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Discussion Starter · #1 ·
Guys,

Happy New Year!

I posted this item a little while back: http://www.chevelles.com/forum/Forum22/HTML/002576.html

67 SS 396 ... 4 spd ... PS/PB/Air Cond

With the holiday and some free time I have done some trouble-shooting. Using a multi-meter, when the problem occurs, I am seeing approx 8.5 volts when the key is turned ... I am getting about 5 volts at the starter. At the battery, I have a full 12 volts. At the alternator I see a full 12 volts ... ( these readings are with the car off ) . With these readings, I have not enough juice to start the car. I can use a booster and start the car. The question is how do I go about finding the cause for the current drop. The battery, alternator, and voltage regulator are all less that 1 yr old .

Could the ignition switch be the problem? I am going to swap the battery. I could try the Ford Solenoid trick, but how much juice is necessary to trip the relay. As a temp bypass, I may "hide" a remote starter type switch in the glove box jumping the battery/starter cable to the start pole on the starter solenoid.

These are all ideas running thru my head... The real question is, how to I trouble shoot a current drop? Should I approach this like a current drain and look to disable any circuit drawing juice with the car off ? Any ideas or suggestions would be greatly appreciated. Thanks in advance ... sdtsdt
 

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“I am getting about 5 volts at the starter”

I’m assuming the 5V reading is on the S terminal of the start solenoid while trying to start.
I recommend you inspect the start circuit wiring. Starting at the battery you should have a #14 fusible link from the positive post to the J-block, it may have been replaced with non fusible link wire, either way make sure both ends have good clean connections. The next section is from the J-block to the horn relay (#10 red) this wire has a soldered junction about 6” from the horn relay the alternator output and one voltage regulator wire connects, it is typically not a problem connection but could be. Then horn relay to bulkhead connector (also #10 red), you can disconnect the bulkhead connection to inspect for good clean connection. Next section is inside under the dash, you have a connection from the bulkhead connector to the ignition switch (#12 red). If you 67 came from the factory with a manual trans, the next section will be from the ignition switch to the bulkhead connector (#12 purple/white could be just purple), if it had an auto trans the wiring will be ppl/wh to a neutral safety switch connector then ppl to the bulkhead, if this is the case you should have a jumper in place of the switch. I’m sure you know, the wiring under the dash is not easily accessible. Back under the hood in the engine harness you will have a wire from the bulkhead connector to the S terminal on solenoid (#12 ppl).

You can inspect the accessible wiring/connections but before you tear into the under dash wiring you can measure voltage when the problem occurs. When it happens connect your volt meter to the horn relay then try to start. If you measure a significant voltage drop the problem is between the relay and the bat. Next read the voltage at the fuse block, at the IGN FUSED terminal. Again try to start, a voltage drop at this point would indicate a problem from the horn relay to the bulkhead to the ignition switch. If you have a neut safety switch connector you can measure the voltage at that jumper location.

” Could the ignition switch be the problem?”

Yes the problem can be the ignition switch. And a ford solenoid has been used to correct this type of starting problem, usually hot starting problem, on many Chevelles.

From the factory with new wiring and good clean connections the start circuit worked fine. However this type of starting problem was common when these cars were just a few years old. GM changed the main power feed to the bulkhead on the 72’s, it eliminated about 10 feet of wiring and was an improvement.
 

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make sure that you confirm the battery is good before you dig too deep. Try another one
or try that one in another vehicle. Just because its reads 12 volts does not always mean its ok. The only way to really tell is to load test it. After that roll up your sleeves and dig in with Elrees post in hand.
 

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Discussion Starter · #4 ·
Elree, thanks for a great post . You too turbo ... I am going to start by replacing the battery and then walk thru all of the easily accessible connections. If the problem re-occurs, I will then go under the dash. Once again, thanks guys for the helpful and informative posts .... Steven
 

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Another way to troubleshoot is to put connect the meter leads across the item you want to test. ie, at the switch, connect to the red power wire and the purple start wire. Ideally, there should be no voltage measurement when you switch to start but at any rate should be less than something like 1/2 volt.

The other thing that could be the problem is the starter solenoid. Sometimes, when they go bad they begin to draw a higher current and that makes the voltage drop high which them means it won't engage. I just changed the solenoid in my car and it's worked good since then. It would never energize while hot and was a crapshoot when cold.

Peter
 
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