'68 Emerg. brake causes GEN light to come on [Archive] - Chevelle Tech

: '68 Emerg. brake causes GEN light to come on


68Phoenix
Dec 14th, 08, 6:55 PM
Fought this long enough. Need help. When my emergency brake is on, the Generator idiot light comes on at a very low level. The brake light also comes on almost imperceptibly.

This occurs with key in ACC position, or in ON position with engine running or not. Take of the emergency brake, and the GEN light goes out. :confused:

I did just re-wire the fuse panel :D, but everything in fuse panel and bulk head has been double-checked. In fact, I've been going through my entire electrical system (2-wire alternator) cleaning and tightening connectors after I had a short-circuit a month ago that melted my high-beam "dimmer" switch and headlight switch which have been replaced. As I understand it, the GEN light grounds through the voltage regulator. The brake light grounds through the emergency brake switch, or the distribution valve. Checked those and they look OK although I haven't tested the VR.

Ark68SS
Dec 14th, 08, 10:56 PM
Are you saying that the "BRAKE" light is barely on? If that's what is happening, then I suspect that the BRAKE light isn't getting a good ground from the switch at the parking brake and it's back feeding through the cluster into the GEN light. Pull the wire off of the parking brake switch and ground it. See if that makes the BRAKE light brighter and the GEN light stay off. If that's the case, then your switch isn't making a good ground.
BillL

68Phoenix
Dec 15th, 08, 12:44 AM
I grounded the feed wire to the switch, but it didn't change anything. The Generator idiot light comes on about one-third. The BRAKE idiot light is on about one-tenth. These come on when the key is in the ACC position, or when the engine is running and only if the emergency brake is on. The emergency brake indicator (idiot) light has always worked fine in the past.

Both lights go out when the emergency brake is released. All other lights work. In fact all other electrical circuits appear to be working. However, I have noticed one end of the "accessories / tail" fuse is getting hot. It's only the inside end, near the center of the fusebox. I noticed when disassembling the old fusebox, this connector looked like it has been hot for while. I re-cleaned the connector and tightened it even more, but it hasn't changed anything. I'm not sure if these are related problems, or just co-incidental. This is possibly related to the meltdown I had coming back from Little Rock.

It DOES seem like there's a poor ground somewhere. I'll triple check the brake distribution valve ground in the AM.

Thanks for the suggestion Bill.

68Phoenix
Dec 15th, 08, 1:38 PM
Well I forgot to check the distribution valve this morning as it was zero degrees with the wind chill and I locked my self out of my running work car and the house. Great Monday morning. :mad:

Anyway, a related question is: What would cause one end of a fuse to get hot?

If the fuse was hot at both ends, or if the fuse blows it would suggest a short. In this case, a lot of resistance at that point in the wiring is the best answer... right? (Elree?). Since cleaning the fuse clip-holder didn't help, the resistance may be in the wire. So, should I try replacing that wire-end and fuse holder? This (hot) side of the fuse has a clip connected to an orange wire that I believe goes to the ignition switch (I'm going from memory here after pouring over the wiring diagrams last night). Maybe I should replace the entire wire from the fusebox to the ignition switch? The non-hot, other side of the fuse connects to a large Red wire supplying multiple fuses.

Note that my working accessories (tachometer, tach and gauge lights, radio, etc) are connected to the fuse box at the appropriate busses, not spliced into wires. I have removed all these connections, but the problem persists. When the GEN and BRAKE lights go out, the fuse cools down.

Suggestions? (Yeah I know.... all I need is $400 to buy new wiring, but it's a recession). Thanks!

68KMENO
Dec 15th, 08, 2:03 PM
if you cleaned the connection for the fuse & still have one end getting hot .... more then likely its where the wire itself is crimped to the end that's the poor connection

68Phoenix
Dec 15th, 08, 10:20 PM
if you cleaned the connection for the fuse & still have one end getting hot .... more then likely its where the wire itself is crimped to the end that's the poor connectionWell I changed out the end of the orange wire and checked the brake distribution valve connector. The brake distribution connector is clean and the new connector didn't get hot but it was because of the dead battery....

Dead battery. New symptom... Not completely new as it happened once since the last trip where all the switches were fried in the headlight circuit. I thought the short was one of the switches I replaced (the dimmer-switch). Now I have a short to search for outside of the switches. :sad:

68Phoenix
Dec 17th, 08, 12:32 AM
Okay, new fuse end, battery charged, turn on lights, heat is gone from fusebox. Forget that issue.

So I'm back to having my Generator light on when the emergency brake is pressed. Only occurs when key is turned to ACC position, or to "ON" position. I also may have a short somewhere. I need some guidance chasing down the short. Do I pull the Negative battery terminal and start checking the fuses at the fusebox one at a time for voltage/current?

I'm not stupid about wiring, but this car was a mess when I got it. Below is a picture of the wiring shortly after I got the car and AFTER I cleaned things up to get the car running. :sad: That was 5 years ago. Now, the only circuits that aren't correct is the backup-light circuit, which is still operating off a toggle-switch (as were the wipers, the interior lights, etc.), and the hazard blinker, where I haven't dug into it but the switch has always been obviously broken. I'm pulling the backup wires now and found they have been spliced, but until I get them all exposed I won't know how bad it really is.

Help me get over this hump! The wiring is almost fixed! :yes:

68Phoenix
Dec 17th, 08, 1:00 AM
Just for a laugh, how about these posts from ME in September, 2004.

"I noticed a couple other slight oddities: When the ignition is turned to ACCesories, the generator and brake light both come on very VERY dim. Only a couple of volts. Otherwise all the lights work fine. ":(

*************

"My service manual says that the wiper motor should have a dark blue, yellow, and black wire, and the washer should have a light blue, and yellow wire. But on my car the light blue and the dark blue are reversed. Which is correct? How can I fix this?" :confused:

*************

So I still have weakly glowing GEN and BRAKE lights, and guess what happened after replacing the headlight and dimmer switch, then rewiring the fusebox.... yep, the wiper motor blue and light blue wires had to be reversed for the wipers to work properly. :cool: Of course, there's been a LOT of re-wiring done in between. Mostly at Chevellabration(s). If this stuff wasn't so much fun it'd be a d@#$ shame.

__________________

undee70ss
Dec 17th, 08, 4:39 AM
I was reluctant to post earlier since Im guessing............................

Do all the other idiot lights work?

The way its supposed to be
Key on and engine off... GEN light on, oil light on, temp light off

Key in start position, engine cranking... GEN light on, temp light on, oil light may or may not be on depending on how fast starter spins.

Key on, engine running, all lights off unless theres a problem.

If your idiot lights do not work exactly as posted above, check the gauges fuse, and/or wiring.

The E Brake light is fed from IGN switch (black/pink) and grounded at parking brake switch. The GEN light is fed from IGN switch (black/pink) and grounded at VR. (brown) There is also a bypass wire from IGN switch (brown w/whitestripe, which is also a resistance wire) that ties into the GEN light between the GEN light and VR. (this is for keeping the charging system working in case GEN bulb burns out.) I suspect you don't have any power on the black/pinks (thats comming from IGN switch). With power comming from the brown w/whitestripe, it will backfeed the GEN bulb, ground through the black/pinks to the E Brake bulb to the parking brake switch when it is grounded. Both bulbs will be dimmly lit (since they would be in series and only getting power from the resistance wire.)

68Phoenix
Dec 17th, 08, 9:07 AM
Greg,
You are correct that the idiot lights are NOT working correctly. I had actually just checked them late last night but was too tired to post the description.

I did check the gauges fuse for continuity before I installed it (it was a used fuse from the donor fusebox), but there's no reason I shouldn't put in a new one. Bill L also suggested earlier I might be getting this current backfeed. Since I know that I don't know and know you do know, I know you're right.:yes:

Time to pull the gauge cluster and trace the pink/black and find the brown with white stripe wire. I wouldn't mind pulling the gauges if it wasn't for prying all those dang light sockets off the back (or I could just let the bulbs all fall inside). When you have a convertible :thumbsup:, this is what winter is all about. At least I had enough common sense to pull the seats out before I started this.

THANKS!

Ark68SS
Dec 17th, 08, 12:24 PM
Pete, a 12v test light is your friend, an ohmeter can be your enemy. Use the test light or a DVOM to check the fuses, be sure you have a bright light and/or 12v on both sides of the fuse.
To test for your short, pull the - battery cable, clamp the test light to the battery post, put the probe end into the cable. If it lights up, you have a draw or a short. Pull the fuses one at a time, if the light goes out, that's the circuit with the problem. If you pull all the fuses and the light's still on, then disconnect the power wires from the horn relay and the junction block behind the battery. If it remains on after that, unplug the voltage regulator, then pull the wires off of the alternator.
Be sure that the doors are closed and no lights are left on before doing these tests.
Give me a call if you need to, I'll try to help you out.
BillL