More electrical gremlins

[sierraspider]

Was and probably still am suffering intermittent starting problems, but first I'm not getting any charge or oil idiots lights when key is on. Also voltage at battery drops to below 12 when running. How do I check and fix idiot lights and test alternator output. About 2 weeks ago I went through every ground and connection (one at a time ) in engine bay and cleaned, sanded tightened, and non-oxed aluminum ones. I charged battery (new) and have 12.5 when key off, but when it starts and I put it under load (lights,fan) voltage drops. Alternator seems obvious, but I'd like to thoroughly test it before I replace it.

So I guess I'm looking for a logical way to test systems. any help would be appreiated>

[bradartigue]

The last time I saw this the owner had a new battery, new battery leads, and the new battery terminal connectors were painted on the inside, making the connection under heavy load drop to about 8V, it would kill everything in the car. So start there, make sure the terminals and connectors are very well brushed and snug. Then follow the wires - to the engine bay, check for a voltage drop at the alternator, then to the ignition switch, check for a drop there, then to the starter, etc.

I doubt the idiot lights themselves are the problem; it sounds like a low voltage issue to me.

[wizard124]

If the alternator warning light is inoperative, the alternator will not charge! So your problem could be as simple as a broken filament in the warning light bulb. Fix this first.

My oil pressure warning light is a bit tempermental. Sometimes, just reaching up under the dash and pushing on the socket gets it to light up.

[sierraspider]

Brad & Wizard
Thanks for the responses. I have a difficult time with electrical stuff (something to do with my ADHD) Brad do you have a link for your wiring diagram for 82 spider. Do I check voltages with key in on position or while running? Wizard, can I get to bulb from under dash or do I have to pull 4 thumbscrews and remove instrument panel (is it a pain?) Any logical steps/tricks would help.How do I test alternator output? At battery or alternator when running? Sorry for the dumb ?s

[jandarah]

Hi, my Spider has the battery in the rear (boot in Australia, trunk in US). Fiat, in their wisdom, just grounded the battery at the battery box. So, it might be an overkill, but I purchased some bulk welding cable and ran the negative up to the front chassis and engine. I have retained the original ground at the rear, but now full battery at the front. One hole to drill at the front and rear, but overall an easy and satisfying job.

Cheers,

[sierraspider]

Brad?Wizard
Put up a post asking for a little help, as I'm an electrical newt. If you get time please respond.

Thanks

[Ptoneill]

Try this link to the various electrical diagrams. http://www.artigue.com/fiat/

Also be advised that there is a ground lug like the ones in the engine compartment under the dash, it Is towards the top.


Removing the front wood gauge cover is not hard you don't need to pull all the gauges just remove the bulb in the alt gauge, very simple....it is helpful to remove the steering wheel to give more working room but not necessary.


Good luck!

[sierraspider]

Thanks Pat
I'll get after it this weekend.