I know this has been covered a thousand times but its got me stumped. When my Elco gets hot(200+)it doesn't want to start. When I turn the key the solinoid clicks and that's it. Also the water temp guage and the ammeter peg. This never happened until this summer.
I've replaced the battery and battery cables, installed a Powermaster mini-starter(plenty of header clearance), and installed a new wiring harness including the purple wire to the starter. I've even grounded the neg battery cable to the block instead of the alternator bracket with no luck. When I jump the starter with a screwdriver it turns every time. There's a big car show/cruise this weekend and its definetely going to be hot. Any help would be greatly appreciated.

1001. You are getting poor voltage on the purple wire. The screwdriver trick bypasses the purple wire, thats why it works everytime. Since you already replaced the harness, check the IGN switch and the neutral safety switch. Bad contacts in these switches put resistance on the purple wire circuit.

Thanks for the reply undee70ss. I've replaced all the underhood wiring but I haven't touched the mess under my dash. I'll start with the ignition switch and nuetral safety switch.

I would install a "hot start" solenoid. It is very simple to install using a constant duty type solenoid and some simple wiring that I can tell you how to install in about an hour. The purpose of the hot start is that it puts full battery voltage and amperage to the "start" side of the starter solenoid. Let me know if you want me to tell you how to wire it.

Hey Randy, that sounds like a good idea. Can you tell me how to wire it up? Thanks...Chris.

http://www.novaresource.org/images/solenoid04.gif

The original purple wire goes to 86 on the relay.

I'm watching this post closely as I'd like to resolve my "heat soak" issue as well which it doesn't help that I've got 22 initial timing either. How do I know if my selonoid is one of the constant duty type that Randy mentions? Also, do I have the 30 amp relay already in the car(firewall?) or does that need to be purchased? What gauge wires should be used?

Sorry to jump into your post BigBlock but maybe we can learn together.

http://www.novaresource.org/images/solenoid01.gif

This diagram is the stock wiring. You need to add the relay and the associated wiring. The relay will provide a direct path from the battery to the solenoid coil. I would use 10 gauge wire from the battery to 30 and from 87 to the solenoid. The other wiring can be smaller as the current is much less.

Thanks a lot.

I just replaced my ignition switch and nuetral safety switch to be safe because they looked like they had seen better days. The starting problem hasn't returned yet but I'm going to add that relay just for some extra insurance. Thanks!!

I thank you too as I'm calling about a 30 amp relay today and will hopefully resolve this issue. My neutral safety switch has been removed by previous owner and jumpered but that doesn't change anything, correct? I will still hook the purple to 86 on the relay?

You can get the relay in any auto parts store or Radio Shack. Just ask for a 'Bosch' relay.

Does it need to be grounded with a wire or does attaching it to the rad support or firewall ground it? Napa has a 4 wire relay instead of 5 as on the diagram and I don't want to screw it up.

Does anyone have the part # of the Bosch relay I need? Napa is trying to cross reference it for me.

thanks

Got the correct relay from NAPA but I've got one more question: What kind of connector do I use to hook the 10 gauge wire up to the battery terminal/cable? I already have one small wire coming out of the cable end going to the radiator support but it's built right in to the cable end.

No such thing as a hot start relay. Undee70ss answered Bigblock71SS's question.

Originally posted by John_Muha:
No such thing as a hot start relay. Undee70ss answered Bigblock71SS's question. Maybe we could call it a 'cost effective' relay. The $8 part will do the same thing as replacing all the wiring and components.
You really don't have 'poor voltage' on the purple wire, you have insufficient current flow. Solenoids are current operated devices. Changing the circuit load from the low resistance of the starter solenoid to the relatively high resistance of the relay coil makes the series resistance of the original circuit minor and significantly reduces its current requirements. Instead of having to carry 8 amps reliably, you need only carry 100 miliamps to energize the relay. Once the relay is energized, it will easily supply the necessary current.

Just a magazine myth to Band-Aid an existing problem.
Fix the real problem and the car will start. I don't need a relay to operate another relay. At least I haven't yet.
JMO
Don't remember when GM started adding a Ford relay under the hood.

I recently installed some performance parts on a 2004 Silverado - you wouldn't believe how many relays the General puts in cars these days. All kinds of little electrical functions are controlled with relays, even the nitrous system.
I never said anything about a Ford relay, a little overkill although they do work well.
I helped my garage landlord rewire his 41 Chevy, no relay problems here. It's a direct acting starter switch, you mash the pedal on the floor and it engages the starter and powers the motor. Simple as it gets. Makes you wonder why GM had to add the extra solenoid circuitry? Maybe so you'd have to replace the wiring and components every 20 years or so? Or add another relay.

Originally posted by onovakind67:
Makes you wonder why GM had to add the extra solenoid circuitry? So women could drive. ;) Plus, it WAS a cumbersome system. An extra pedal.

Sorry for the delay in responding, I had a death in the family and was away for the past couple of days. The above diagrams are true and correct but involve changing too much wiring. Purchase a Cole Herssey contiuous duty (is designed to handle voltage/amps for a long cycle and has a larger contact area) solenoid, part # 24059 from any parts store. The solenoid looks similar to a Ford starter solenoid but is zink plated rather that the black body. I'll try and explain this, but if you have any questions let me know. There is 2 large studs (5/16) on the sides. Run minimum of a 12 gauge wire from battery to one stud, run another wire from the large stud to the (S) terminal on the starter. These large studs are the "contacts" and allow full battery amperage to your starter. Now, the wire that runs to the "S" terminal is removed and gets extended and installed to one of the small studs on face of the solenoid. The remaining small stud simply runs to a ground source (make sure it is a goood ground). The small studs are the "coil" side and when you turn the ignition switch to start, will pull the coil in and close the contacts sending full amps to the started. No nead to interupt the nuetral safety switch, because the small wire already runs through it. This solenoid also is designed to take the heat under the hood. We run this setup at O'hare field on hundreds of pieces of equipment that stop and start in the heat several time a day, it works, is approved by Cole Herssey and is simple to install.

And there is such a thing as a "hot Start" relay, and sometimes it isn't possible to "fix" the problem. Heavy equipment and many race guys run the setup. Also high compression race engines often have problems starting when hot. I am not sure what engine setup that he is running, so I jsut ofered some proven and approved (by Cole Herssey and several manufactures) help.

Old Hot Rod readers have probably read this setup several times in the past too

How does the wiring on the C-H relay differ from the diagrams that involve "too much wiring"?

Don't know why it wouldn't be possible to fix the problem rather than fix the symptom.
(We are talking about Chevelles here, not heavy equipment, right?)

Anyway if I was going to fix the symptom by adding another relay, I personally would go ahead and use the heavy duty solenoid that Randy B suggested or at least a standard Ford starter solenoid rather than the dinky little Bosch relay.
I mean if your going to all that trouble, why not?

Sorry onovakind, after sending my post, I realized your diagram is the same. I just crawled out of bed and didn't look close enough. Sorry, didn't mean to do that to you!!

Dean you are right, we are talking chevelles, I just used that for an example to the post that said that there wasn't such a thing as a hot start. Hot start is simply a generic term, I don't mean to be controversial, just trying to help out. Thanks.

Originally posted by Randall B.:
just trying to help out. Thanks. And everyone certainly appreciates that !

graemlins/thumbsup.gif

OK, I did everything according to onovakind's diagram using 10 gauge wire, grounded it to the firewall and only exception is I got an Echlin relay from Napa that cross-referenced the bosch. I just got in from taking for a test drive around the block. Pulled in the driveway, shut it off and tried to start. No change. Will turn over very slowly but will not start. I had my alternator and battery to Autozone also and both checked out good. I'm getting frustrated. Can't take the car anywhere unless you plan on letting it run or waiting until things cool down. Do I try Randall B.'s suggestion next? Would someone explain to me what exactly is causing this? Never had a problem until I installed headers. Are they heating up my cast iron starter? I do have a shield on the selonoid already but still having a problem. Will a high torque mini starter solve it?

Originally posted by Dean:
Don't know why it wouldn't be possible to fix the problem rather than fix the symptom.
(We are talking about Chevelles here, not heavy equipment, right?)

Anyway if I was going to fix the symptom by adding another relay, I personally would go ahead and use the heavy duty solenoid that Randy B suggested or at least a standard Ford starter solenoid rather than the dinky little Bosch relay.
I mean if your going to all that trouble, why not? If we were to use the same 100 amp standards for repairing the problem would we add a 100 amp ignition switch and a 100 amp neutral safety switch? Rewire the entire circuit with 8 gauge wire? Probably not. We would find a stock ignition switch and a stock safety switch, the same kind that failed once and put them in.

The circuit current is about 10 amps max - I think a 30 amp relay would be up to the task. What kind of relay(s) would you use on an electric fan that draws 30 or 40 amps? C-H 100 amp relays in parallel?

What's going on here? Left it cool down a few hours and still could barely turn over. Hooked jumper cables up from running car and started right up. Backed it in the garage and checked/rechecked all my connections. Wouldn't start. Put my 50 amp boost/starter on it and started right up the first time. With booster still hooked up, tried to restart and would only click and hum unless it was the booster humming. What next?

I only assumed that we had checked the starter motor amp draw before I left my posts with regard to adding the solenoid. Scott, find a shop that has a true VAT (volt amp tester) that can check starter draw when it is hot and cold. Chances are you have a bad starter. not a wiring problem.

Originally posted by Randall B.:
Old Hot Rod readers have probably read this setup several times in the past too Hate to disbute Old Hot Rodders and Shade Tree mechanics.

Ok, John what's the point? The article ran in Hot Rod magazine, I said nothing about "old hot rodders" or "shade tree mechanics". I was simply trying to offer some help from the information that was provided! I read all of the way back to the begining of this mess and I see no offer of opinion from you other than short comments. Aren't you supposed to be the "moderator" for this? Enough! Offer some assistance if you know aht problem he is having, and if you can fix it over the computer, you are the best thing to happen to cars since fuel injection.

Well, the starting problem is back again even after replacing the ignition switch and nuetral safety switch. I've been reluctant to install the extra relay("hot start") because I really want to solve the problem, not cover it up.(no offense)

I need to get my multi-meter back from a friend so I can check and see where the voltage drop is.
What else can it be? I've replaced/cleaned just about every componenet that I can think of.

For a recap, I've replaced the battery and cables, installed a mini starter, new M&H engine harnesses, new ignition and nuetral safety switches, checked/cleaned grounds and connections.

Like wolfehunter, I can't really drive this thing untill I figure this out. Just when I got my car running great and I thought everything was fine, this has happened! Thanks again everyone for all your replies.

It's not like you're cutting the car up to install a relay. You can do a temporary installation in 20 minutes and see if this cures the symptoms. If the problem persists, you know that the internal wiring in the dash is okay. If the relay cures the symptoms, then you know you're not getting enough current through your brand new switches. Then what?

Originally posted by onovakind67:
.
If we were to use the same 100 amp standards for repairing the problem would we add a 100 amp ignition switch and a 100 amp neutral safety switch? Rewire the entire circuit with 8 gauge wire? Probably not. We would find a stock ignition switch and a stock safety switch, the same kind that failed once and put them in.

The circuit current is about 10 amps max - I think a 30 amp relay would be up to the task. What kind of relay(s) would you use on an electric fan that draws 30 or 40 amps? C-H 100 amp relays in parallel? Sorry onovakind67, I didn't mean to imply the "dinky" Bosch relay wouldn't do a good job of bypassing the control circuit and like you said certainly it would be the most simple and cost effective "first try test" then if it did fix the problem, you're done.

As I said "IF I was going to do it "I personally" would just go ahead and use the Ford type solenoid and bypass the high amp load too, sorta like in Wes Van's tech ref article (http://www.chevelles.com/techref/ftecref4.html).

That's just my personal opinion of how I would do it, not trying to say your way wouldn't work OK or other people should necessarily do it "my way".

graemlins/beers.gif

Originally posted by BigBlock71SS:
Well, the starting problem is back again even after replacing the ignition switch and nuetral safety switch.

For a test you could run new wire from the battery to the IGN switch to replace the power wire (always hot wire). If problem goes away the trouble is upstream of the IGN switch. If it continues its downstream. Use at least a 10 ga wire and put a inline fuse close to the battery.

Originally posted by wolfehunter:
I just got in from taking for a test drive around the block. Pulled in the driveway, shut it off and tried to start. No change. Will turn over very slowly but will not start. Originally posted by wolfehunter:
What's going on here? Left it cool down a few hours and still could barely turn over. Hooked jumper cables up from running car and started right up. Backed it in the garage and checked/rechecked all my connections. Wouldn't start. Put my 50 amp boost/starter on it and started right up the first time. With booster still hooked up, tried to restart and would only click and hum unless it was the booster humming. Your problem is different BigBlock71SS. After reading some of your past posts (http://www.chevelles.com/cgi-bin/forum/ultimatebb.cgi/topic/4/22199.html?) , I would first retard the IGN timing. If it cranks then you may need a retard module.

Sorry onovakind67 I see your point as using the relay as a troubleshooting tool not necessarily a permanent solution.

Here's an idea:

** Use caution** This could be dangerous.

1) Disconnect the Negative battery cable.
2) With the engine cold, using a 4 foot length of #18 or bigger wire and a ring terminal, connect the wire/ring terminal to the "S" post on the starter solenoid.
3) Take whatever means necessary to prevent contact of the wire installed in step #2 to ground.
4) Reconnect battery
5) Start/Drive vehicle and get it up to temperature where problem occurs, and return to your shop.
6) Shut off the engine, then put the key back in the "run" position.
6) Using appropriate safety gear, touch the conductors of the wire installed in step #2 to the positive post of the battery.

A) If the engine cranks and starts, you have a problem in the circuits feeding the starter solenoid.
B) If the engine cranks slowly or not at all, there is a solenoid problem, a starter problem, or a starter/engine block to chassis ground problem.

"A" is difficult. You'll need to eliminate each break in the circuit individually. Your post states you've replaced the "components" of the system. What about checking what is feeding them. Voltage drop, connection integrity, etc.

"B" is easy. You've got a bad starter, solenoid, or combo of both, OR an ineadequate ground from the engine to chassis/body/battery.

My .02 - Sorry for the CYA text, but I'm in that kind of mood. I failed to mention that the Positive connections are as valuable as well! ;)

The most important thing to remember when doing starter cranking tests is to make sure the transmission is not in gear first.
Double check, heck triple check it.

My son's friend (the same guy that started his 69 Chevelle and started filling the automatic transmission that he had just finished installing with fluid and when it had enough fluid the car took off and smashed my battery charger up against the work bench) crawled under his Chevy van to bypass the starter solenoid and when it started it ran over and killed him.
:(

Although not the same problem as BigBlock it is similar in that I had problems when the car was hot(heat soak). But now I think my starter is DONE as it will only turn over very slowly when cold. I've got 11.40 volts at the battery and ran a jumper wire(10 gauge) to the "S" terminal on the selonoid and touched the + battery cable with the same results. When a starter or selonoid "dies", are these the symptoms? It will give one initial groan but can't turn over. That selonoid is only 3 months old but it is a "cheap" Autozone product. Guess I need to pull the starter & selonoid and get them tested. I even backed my timing off but just won't turn over.

I've been watching this post because I was having the same problem with the engine not wanting to turn over when hot.
I solved my problem by upping the size of the battery cables from 4 gauge to 2 gauge and making sure that the negative wire had a good ground to the engine block and chassy.
Autozone sells the 2 gauge battery cables for around $10 to $12 apiece with molded ends on them.
As a funny side note: today when I finished putting the new battery cables on I took the chevelle to return a rented movie. A guy with a '70 elky (BB and tubbed) pulled up next to me at the video store. We talked and exchanged "nice car" graemlins/thumbsup.gif . Then I went in to rent a movie. When I came out his car would not start! He said he was having the same problem when it gets hot. We put jumper cables on it and it fired right up graemlins/hurray.gif When was the last time you seen a '70 SS 396 jump starting a '70 SS elky? smile.gif

Let's all take a deep breath.

- We all know Chevy solenoids and starters have always been prone to heat problems, especially when stock exhaust designs changed and are run close to the staters. My old 73 Monte went thru 4 starters in 100K mi. That doesn't included the ones that I put on that didn't last more than a couple of months and got returned. The only ones that lasted were genuine NEW GM high torque starters. Most garages I know wont use a substitue due to the high failure/return rate. Moral = Don't trade price for reliability.

- The reason there are so many relays in todays vehicles is because it's a safer, more reliable and more cost effective method of current switching than running the juice thru feet/yards of wire all over the vehicle, thru multiple contacts and then to the load. Every pair of contacts degrades the electrical performance and reliability of the circuit. This is a fact, not opinion. However, with a relay controled circuit, there is generally only one set of contacts between the supply (battery) and the load, and as little wire as possible. Thus, there is less current loss in the circuit (read more efficiency). There's also the safety thing of not running high current circuits all over the place. Go back and read these posts; "Is it the netral switch, the ingitioin switch, the wires, the connectors, etc etc???" Relay-switched circuits use low current "signals" to control high current load circuits. It's sound electrical engineering. Now before everyone jumps on me about originality, or reminds me that this has worked just fine for 30 years when everytinng is in prime condition, let me just say that it's totally up to the individual whether to use a relay or not. The fact GM didn't 30 years ago doesn't mean it was the best, safest or most efficient way. It could mean that it was the cheapest way to do the job with an "acceptable rate of failure". GM was/is after all, in business to be in business, to maximize profit, minimize cost/expense. Every $.50 saved on 2 million cars was another $1M in the bank. But we also know that these cars for the most part, started and ran just fine in their originally designed configurations and were extremely reliable.

In my humble opinion, both solutions are perfectly acceptable. Let's focus trying to help our friends solve their problems.

Scott, I think you have a weak solenoid, starter (or both) provididng your battery and cables (and connections) are sound. You may wish to consider a NEW GM unit or a NAPA high torque, lifetime unit. It isn't Autozone that's going to be stranded due to an inferior grade of starter. BUT, be sure to load test the battery, and the cables first. Make sure the GROUNDS are solid too. Let's see, battery, cables, connections, solenoid, starter motor. There ain't nothin' else it could. Your "hot wire" test eliminated the switches and other wiring.

Bigblock, you may want to also measure the current draw of the "mini" you installed (as undee suggested to Scott also).

There's no such thing as too large a cable when it comes to DC (providing you can mechanically terminate it reliably). #2 is better than #4. Glen's tip is a good one. Also, it's almost impossible to assess the health of a battery cable that appears to be solid and clean. It could be terrible electrically. Only a device called a "megger" can do that. Not auto shop I know of has one. So if in doubt, do as Glen suggested, replace.

Hope you guys let me know what solved your problems.

If I may add my 2 cents. If you are trying to crank a hot BB with anywhere near 20* initiall your time would be better spent looking for a way to retard the timing at cranking rpm. There are dozens of ways to do this. I have my dist setup with manifold vac advance rather than ported. that allows a lower initiall setting(read cranks OK hot)and my weights dialed in to a good advance curve. Others here have their way. but I say fix the high cranking timing that will fix everything else. good luck

Milan

My 454 set up would be hard to start after warmed up. Has hooker headers very close to the starter and solenoid. Even though hard to start it didn't take too long to get it started, so I lived with it. I just detailed the engine and engine bay, and while I was at it Added the heatshield to the starter and one to the solenoid. Replaced both battery cables. These particular heat shields are aluminum with some type of heat resistant material glued in side and they wrap around the starter and solenoid, From The Muscle Factory. They have been on for 2 weeks now and the starter works perfect. After a long ride, shut the engine off, and turn the key back on with out giving it gas and feels like a brand new battery started engine up. Works for me, eng. temp always 180.