Charging/brake light question

[johnnydisco]

Recently, my Tercel, upon starting, has had the charging and brake light
on. After a few high revs, it would go out. I would also notice a slight
increase in brightness of the headlights when it happens at night.
The belts are tight and battery terminals tight on a new battery.

Any help ?

[Neu]

Hmm..my brake light stays on for a few seconds.

I'd top your brake fluid reserve with dot 3 and see if that helps with the brake light.


The brightness thing is normal.

[Logbear]

With my main "86" Tercel sick with a bad tranny, I was going to use my sons "83" that we just got through working on. And then just the other day I go to drive it and I got the same thing. Both the charge light and the brake light are on. When I pull the parking brake both lights gets a little bit brighter. Brake fluid level is fine and a quick check with a volt meter shows 14.45 running with lights and heater fan blowing, and 12.57 not running so I'm pretty well convinced that I don't have a brake problem or a charging problem.

I found some other threads that talk about a charge light relay being the problem, but I can't locate this mysterious charge light relay on my "83".

To make this mystery more intriguing the fuel gauge also doesn't work. But the fuel gauge didn't work before the charge and brake light came on.

I've replaced the fuel tank sending unit with one that I knew worked from another tercel and the gauge still doesn't work. And then I replaced the instrument cluster with one that was working from another tercel and the fuel gauge still doesn't work.

Are these things all somehow related, or is the fuel gauge problem separate from the charge/brake light problem.

I've been thinking some sort of ground problem. Or is this a sign of something about to go bad with the alternator. I could swap alternators and see.

[takza]

Recently, my Tercel, upon starting, has had the charging and brake light
on. After a few high revs, it would go out. I would also notice a slight
increase in brightness of the headlights when it happens at night.
The belts are tight and battery terminals tight on a new battery.

Any help ?

Regulator about to go out? I had a Nissan that did this for maybe 2-3 winters...and I never fixed it.

[Neu]

its a ground issue.pull the instrument cluster off and check around

[Logbear]

I've been looking at the wiring diagram looking for ground points to check. The "fuel level sender" shows two wires going to ground (or is it one depending on the vehicle?) The wires are labeled "For S/D" and "For W/G". What does S/D and W/G mean?

I'm also trying to figure out if this "83" has a charge light relay. And if it has one, where it is.

[ARCHINSTL]

"S/D" and "W/G" are probably "sedan" and "wagon." "Sed" and "wag" would seem more logical, though.
Tom M.

[SynthDesign]

its a ground issue.pull the instrument cluster off and check around

Most likely not the grounding points, but other wires grounding out. Right?
This can happen because wires may of got crushed, worn, or over heated/fried or oily/dust/contamination is conducting and grounding. My incline-o-meter stopped working thanks to host of dust and turpentined grease. Quick blast of denatured Alcohol and HS2000 and back and working great.

[Logbear]

Well after a short afternoon fiddling with the "83" I don't have a solution yet. But here's what I have done.

I discovered that this car has the external voltage regulator. It looks like sometime in the poor Tercel's past something bad happened with the battery. The radiator fan relay has been rewired due to some damage to the fuse box under the hood. The fan relay now hangs underneath the fuse box with a line drawing on the fuse box pointing to the Rad fan relay. And the voltage regulator looks like an aftermarket replacement with individual wires using push on connectors instead of the big round plug. I looked at one of my parts cars and noticed that there is a condenser mounted under the voltage regulator behind the battery. The car I'm working on had a wire that went nowhere and had no condenser. The wire had the right connector. My son remembered that we found the old condenser all corroded when we did an engine swap. I put the condenser on and plugged it in. But the charge and brake light stayed on. Next I swapped alternators. Still the brake and charge lights are on when the car runs. I checked voltage with the engine running and the voltage increases with the car running. I suppose it could still be the voltage regulator but swapping that would mean snipping the wires off the plug.

After some coffee I'm gonna check the wiring to that rad fan relay and see if something is messed up there. I pulled the gauge cluster since I am also looking at the fuel gauge problem and found no wiring or ground defects.

I'll start a new thread about the fuel gauge.

[Logbear]

Well I've tried a lot of different things and checked out a lot of stuff. The only thing I haven't done yet is replace the voltage regulator. I did find something that I don't quite understand. I disconnected the sensor from the brake fluid reservoir to check for continuity to ground. According to the wiring diagram the Wht/blk wire goes to ground on the left side baffle. I found that ground point and cleaned it up. I had continuity between the brake reservoir plug and the wire that goes to the ground point. With the wire off of the ground point the connector on the plug still found ground. And there was continuity between the two terminals on the plug. I'm thinking that the Red/wt wire shouldn't be ground. Isn't that what makes the light come on? When I pull the parking brake both charge and brake lights get brighter. All other warning lights work normally.

[Logbear]

Laying in bed last night fretting about this problem I realized that I can use my other car to compare wiring/grounding issues. How did I forget that!

[Logbear]

OK, I checked the brake light connector in a car that I know works correctly and found that "83" is working OK. Time for a voltage regulator change.

[Logbear]

The voltage regulator was the problem.

I found a loose and corroded wire on one of the connectors that was used to replace the stock plug. As I was pulling the push on connectors apart the wire came out of the connector.

So either the voltage regulator was bad or the bad wire caused the problem.

At any rate the final solution for the Brake/Charge warning lights on at the same time was voltage regulator related.

[takza]

The voltage regulator was the problem.

At any rate the final solution for the Brake/Charge warning lights on at the same time was voltage regulator related.

That is supposed to be a classic symptom...getting it fixed can be a little harder. I've had 2 regulators stop regulating allowing the alt to boil the batteries. Aftermarket regs...the cheap ones...don't last.

[johnnydisco]

FIXED THE PROBLEM!

After deciding it was the alternator, purchased one from Autozone for about $50.
From a few bad experiences, I matched it up before leaving the parking lot, and
realizes it was the wrong one. The parts guy failed to ask me and I didnt know
there were 2 different types; one with and one without a built-in voltage regulator.

2 days and $90 for the rigt one I was off to install it.

It took me about 15 minutes to R & R it I also noticed while removing the positive
cable, it was very loose. This was probably due to the new battery that was installed
2 weeks prior. Maybe I should have checked it after the shop installed it.

Thanks for everyone's advise. Im back on the road again!


Johnny