1981 Fiat Spider 2000

[AlaskanFiat]

Red Battery light comes on. 1981 Fiat Spider 2000. The red battery light on the dash cluster comes on when I turn on the headlight switch, or wiper switch, or heater fan switch. None of the above work when switched on. If I turn these off the red battery light goes off. I have a new battery that puts out 13.04 Volts when not running. When running the battery shows 13.97 volts so I think the alternator is charging OK. The starter turns the engine over fine, starts and runs great. When the key is turned on (not running) I get power to the fuse box on fuses: A. Turn Signals, B. Windshield wiper/Heater Motor G, Front Right parking lamp/rear left tail lamp, H, Front left parking lamp/Parking tail lamp indicators, I. Clock/courtesy light/hazard flasher, L. Horn/Engine Fan Motor, I do not get power to fuses: C, D. E. F. Seams strange that I get power to fuse terminal B. Wiper Motor/Heater Motor and they don't work. Any good ideas on what is wrong with this electrical system? Almost seems like low voltage (Voltage drop) but engine spins over fine when starting??? Any idea if there is an electrical relay that is shutting down these components. All other electrical components like horn, radio, blinkers, marker lights, tail lights, cluster lights, are fine... Confused in Alaska. Thanks Brad

[spider2081]

I think Fuses C,D,E,F are the headlight fuses. They get power with the headlight switch turned on which is with the bat in the down position. Up is off.

[seabeelt]

I have been through this recently, and still not fixed btw. There are a couple of good you tubes from Eric the car guy on testing your battery and alternator. Not all inclusive mind, but a good start. I'm guessing with an 81 you have a 65 amp alt which should be more than adequate to run the systems in the car. Start with the basic tests and clean connections and isolate issues, fan, wipers etc one at a time. If they share the same fuse, that is a good place to look as well.

More details please

[wizard124]

Your first post, so I will assume the car is new to you..

Do a search and download the wiring diagram for your 81; artigue.com

Next, get on your back and look for ugly wire splices from a PO. Loose wire connectors, anything amiss under the dash on the driver's side.

Then, attempt to narrow down the issues. I would pull the B fuse then work the wipers and heater fan on that circuit to see if the results change. Same with the headlights circuits.

If you find a source of your problem, trace that circuit. Look for shorted wires, bad connections, faulty switches...

[AlaskanFiat]

I've had this car for about 10 years. Bought it as a basket case with engine all in parts. Took about a month to get all back together as previous owner had no idea what was going on. Body and interior perfect. Now this electrical issue.... I will follow circuits under dash panel. Maybe something to do with the brown wire to ignition switch causing low voltage to only a few components. Good battery/charging system. The starter motor would take by far the most amps and it turns over fine....
Found this article that makes some sense on voltage drop. http://www.mirafiori.com/faq/content/bwfix/bwfix.htm

[bradartigue]

When this has happened to me it was the voltage regulator.

[seabeelt]

I replaced the voltage regulator on mine and it did not fix the problem. Ended up being the triodes inside the alternator. Fixable, but not by me, in the short term anyway.

[spider2081]

One of the most common causes for the windshield wipers not to work is not electrical. The linkage rusts to the point the motor does not have the power to move the blades. Usually the shaft that passes through the mount on the cowl that the blade attaches to. Some folks drill an 1/8 inch oil hole in them and keep them lubricated once freed.

[Zaffer]

Alaskanfiat, did this fix your issue or are you still hunting it down? It seems like quite a few people (me included) are having this issue at the moment. I done quite a few things including replacing the voltage regulator and the issue is sporadic, but mainly the issue is there. The things I have done are here: http://www.fiatspider.com/f08/viewtopic.php?f=3&t=30868 .

I haven't had much time to work on the car, so I haven't made much progress.

[AlaskanFiat]

Sorry I haven't replied for a while. I'm still in the states but return this week. The alternator is charging as I tested it with a volt meter but I'm not sure if it's enough. I did replace the brushes/voltage regulator three years ago but now I have the red battery light indicating low voltage. If the brown wire splice to ignition switch doesn't change anything (see link earlier) I'm going to take the alternator to an auto electric house in Anchorage.. Thanks