Battery Dash Light & Charging Issues - HELP

[vesnyder]

Was driving over the weekend in my '83 SC and noticed my tach going crazy before it finally died. Got home (thank God) and the bater was dead. Recharged the battery and checked the charging system and all seems OK. Did notice that the battery light on the dash is not working.

Someone told me that this is the problem? That this light completes the circuit and when it is burnt out the charging system is squirrely?

Any confirmation of this? Anyone experienced the same problem? I do remember seeing in previous posts a connection between the light not working and charging problems?

HELP??

[vesnyder]

Just to clarify problem - light in dash is not burnt out, just not lighting, even when the ignition is turned on and not started?

[Roy M]

When this happened to me the connection between the starter and alternator was broken at the starter motor so no charge was getting through. I have an '88 Carrera with the integral regulator which is slightly different from your system so there may be otehr reasons but it would be worth checking!

Still don't know why the open circuit running didn't affect the alternator but it's been ok since.

[Jdub]

Diodes dead at the alternator? Brushes on slip ring defunct? Wire broken at alternator? Was the car's entire lighting system "strobing" from dim to bright at times (at night, naturally)?

In all events, it is time to have the alt. looked at I would think. What sort of voltage are you getting (if any) at the battery terminals from idle up to 4K or thereabouts?

John

[vesnyder]

I was getting what I considered normal voltage at the battery - 13 - 13.5 Volts? The dash battery light not coming on has me stumped?? Saw in a previous post where a guy had the exact symptons and found a bad connection between the alt and starter? The car starts fine after charging the battery so not sure that is it? Will check everything before tearing out the alternator and realizing that is not the problem!

[vesnyder]

Roy M - Just printed out your post from Sept, 2000. Did your car start. Mine starts fine and runs fine after recharging battery?

[Jdub]

Heat may play a part in this. For example you charge the battery and everything is fine, but later, as you drive and temps come up you begin to maybe lose a needed ground or create a bad bridge. I am not sure, but certainly if you don't know the history on the alternator it can't hurt much to pull it and have it rebuilt. That should be about $125.00 or so.

Also, I don't thing your alternator has the remote regulator? It would be easier if you could pull just that item and have at it.

Good luck,
John

[vesnyder]

John - You're right about the integrated voltage regulator, other wise I would have changed it.

Roy - Checked the starter connection and it looked fine - darn!

Here is the latest. Went and checked the voltage at the battery while I was at the wheel and here is what I found. Looked normal when I first started, ~13.5V. As I started to load the system; lights, fog lights, flashers, and radio, the tach went crazy. The voltmeter dropped to around 10V. After shutting down the battery was dead.

Also the alternator/battery light on the dash does not light up when I turn the car on and it is not started.

Should I have the alternator rebuilt?

[Early_S_Man]

Vance,

You are a long ways from being able to make an intelligent decision about having the alternator rebuilt ... you really ought to try troubleshooting to the point of being able to say whether the problem is 'IN' the alternator or not.

1. Pll out the comination gauge.

2. Pull off #61 Blue wire and check the Blue wire continuity to ground. The reading should be staedy and a resistance value ... I'm not sure what the field winding should read on a Paris-Rhone or Valeo.

3. Connect a temporary ground jumper to the lamp holder terminal where the Blue wire connects with the ignition switch on, but the engine not running. If the alternator warning lamp lights, at least you won't have to troubleshoot dash wiring! If the lamp doesn't light ... you son't have to worry about rebuilding the alternator, yet!

[vesnyder]

Warren - Thanks. But don't you think the voltage drop at the alternator under load shows the faulty alternator? Do you think the dash light could be causing this as opposed to the other way around?

[Early_S_Man]

Vance,

There is evidence that the field winding in your alternator is not getting pre-excitation current from the #61 Blue wire ... and, if that is the case -- there is NO OUTPUT from the alternator!

Do the tests I suggested, and let us know what the results are ...

[Jorgeman]

You mentioned the dash light wasn't burned out--just not lighting. Since field excitation occurs thru the dash light (or so I seem to remember)--I'd check that dash lite socket very carefully and also do a continuity check from that spot to the alternator field coil.

[vesnyder]

There are two blue wires attached to the back of the battery/alternator bulb. One showed no continuity to ground the other showed some resistivity. When I connected a temporary ground to the bulb it lit. What does that tell me? What should I look at next?

[rombeiro]

Vance,

It is probably terrible etiquette for the PO to jump into a thread posted by the new owner, but hopefully I can help.....

The same thing (wild gauges, headlights dim, then dead battery)happened to me last May - see the service log printout I gave you with the car. I was also grateful I made it home before the car died. Ed Pimm replaced my alternator and regulator ($400 repair), then everything was fine and no problems after.

If the alternator really IS bad, it seems like the symptom and not the problem. You also might want to call Ed @ his shop (look up EPR Automotive on McKitrick), because I seem to recall there was at least a one-year warranty on the parts? Don't know if it was transferable but it is worth a shot. E-mail me at "rombeiro@yahoo.com" and I will give you his phone number, or I am sure it is listed on one of the service receipts.

Good luck with the repair.

Randal