Fiat Electrical Challenge with Light Signals

[Fiatbrit]

Hello,

I hope this group can assist me. You have all been great in helping a number of times in the past. I have a 1981 Spider that I just had repainted. I received it back from the paint shop and there is a challenge with the lights and signals. They all work fine with the car not running and ignition on. Once I start it and it is running the signals no longer work and all the driving lights look like they are getting a low level of current thru them almost like a short. I think everying is hooked up right but I wonder if the ignition switch went bad again of if there is some other part that failed or that was reconnected incorrectly. WIth the car running and when I turn on the lights it will not run as smooth either like it is drawing current from the ignition. The body shop told me they accidentally left the car ignition on overnight and the battery went dead but after charging it seemed to be fine. Not sure if leaving the ignition on overnight might have fried something that would cause these symptoms? It is almost like with the car running there is a small short. Again not sure if the ignition switch might have fried or something like that?? Please advise and thanks everyone for the help in advance.

[fredguaz]

Did problems start after you had car repainted? First place I would check is all the grounds. Metal to metal contact not metal to paint.
Hope this helps.

[So Cal Mark]

probably bad grounds with fresh paint. You'll need a voltmeter to do any troubleshooting

[DieselSpider]

Yes check for bad grounds, the connections at the battery/starter and also check the voltage at the battery after you start it as it should be over 13 volts and if not then the car is running off the battery not the alternator so that the battery is not getting recharged when the engine is running.

[Fiatbrit]

Thank you for the replies. I did have it repainted and it was working fine prior to that. The shop also switched out my transmission. Is there a ground wire in that vacinity that could have been missed? Where are the grounds? I know of the two on the front vendors, battery box but my guess is there are several others? Please advise when convenient. Thanks again to all.

[aj81spider]

Make sure the ground straps from the engine and the transmission are in place. I suspect you have a couple of problems - the lights sound like they are grounded through fresh paint, and the fact that things get worse when you are running the engine might point to missing ground straps from the engine/transmission to chassis (or paint under those connections as well).

[Fiatbrit]

Agreed. I spoke with the shop that installed the transmission and they advised that there was no ground strap on the transmission. Can someone please advise where the main ground straps are located. Engine to chassis and tranny to chassis for example?

Thanks everyone.

[Fiatbrit]

Hello, I checked and cleaned the grounds and added one from the alternator tension bracket to the inner fender. I have nearly 14Volts at the Battery when running but still falters when the headlights are on and i still get a dim lighting of the driving lights when running and no turn signals when running?? I noticed when i disconnected the front passenger side light connection the engine wanted to quit. Could something in the ignition switch be causing this or a short somewhere? What should i check with my voltmeter? Seems like the engine is getting power thru a reverse circuit since disconnecting the green yellow wires on the passenger side caused that issue. I also don't think there is a ground on my transmission. The shop did hook up my reverse lights and the work but they were not connected prior. Not sure if that could be the issue? Any thoughts??

Thanks again,

[Frog2Spider]

My thought is:
If the back-up lights were disconnected, and if everything worked before they were re-connected, the previous owner may have found the 'simple' solution. Disconnect them again, and see what happens.
Hope you find the problem, but until you do, I'd not leave the battery connected in my absence.

[spider2081]

Can you tell us exactly what (where they are) grounds have you cleaned and or checked. Also you seem to have more than one problem and therefore more than one cause.
Are your running lights,front parking lights, tail lights, and license plate lights dim with the headlight switch in both the parking light position and the headlight position?? The parking light position is powered from the "hot all the time" circuit and the headlight position is powered from the "hot in start and run position". So if they are dim in both positions one might suspect poor grounds, however the tail light and license plate light and rear running light is a single ground is in the trunk and the front parking lights and running lights grounds are at the grounding pods on each fender well under the hood.

Have you removed the front signal/parking light bulbs from the sockets to see if that changes anything. The dual filament bulb can fail by shorting the signal and parking filament together causing strange symptoms.
What RPM is you car idling at with headlight off and on??

[Fiatbrit]

I have cleaned the front pods on each fender, added a ground from the alternator to the inside fender inspected the pod under the dash. I have not done the rear grounds. The parking lights are only very dim when the car is running and the light switch is off. Below are they syptoms with ignition on not running vs. car running.
Ignition on engine not running:
Turn signals work properly. When i turn on the parking lights the turn signals stop working. The headlights are bright with the ignition on and work properly (although the driver's side low beam appears to be burnt out. All the parking and side marker lights work fine with the first click and headlights come on with the switch. Low high also works. The car seems totally normal other than the turn signals not working with the parking lights on.
Car Running:
Light switch off but the parking lights/taillights all around glow very dimly as if they are getting very low voltage. Also the car idles like it should but when i turn on the parking lights or hit the brake lights it wants to stall out. The idle seems to be at normal speed at warm up. The turn signals do not work at all when the car is running. Voltage at battery is around 14 volts.
Would the switch do this. It is not old and has been replaced and worked fine up until the work was done. It is very strange. Lights are never dim except when the car is running and the light switch is off. Also strangely when I disconnect the passenger side front lights the car does not want to run. Thanks for the replies.

[spider2081]

Parking lights glow dimly with switch off.

Can you drop the switch out of dash and unplug it. If the lights still glow dim there is a short in the wiring somewhere.
Was there body work done in the area of the rear wheel arches. The light harness passes by the left side wheel arch on left side drive cars. The harness also contains power wires for radio antenna and the wires for the fuel gauge.

[azruss]

This is still a ground issue. the dim lights just mean the circuit is finding a ground thru the light bulb. Get the back lights operational to see if a proper ground back there solves the issue. Start looking at what got removed with painting and make sure nothing was wired backward. If you have a hot wire/ground switch at one of the devices you will find your problem.

[Fiatbrit]

There was some body work done on the back part of the wheel arches. I did a bit more investigating tonight since it is dark. WIth the ignition on I found the following:

Turn signals work
Brake lights work (outer two bulbs and bright) BUT the rear side marker lights also glow dimly when the brake lights are activated.
Also when the Brake lights are turned on the turn signals stop working.
Same issue with the turn signals when the parking lights are turned on (inner two rear bulbs) the turn signals stop working
When parking lights are tuned on the brake lights go from bright to very dim and the rear side markers are dim as well.
Would this all be a grounding issue at the rear of the car or wires not hooked up correctly? I will have to reinspect all of the rear connections and grounds but any guidance would be helpful. Thanks everyone.

[124JOE]

it sounds like they crossed the wrong wire
now witch one?

I bet its the one for the cig lighter ring light
if you feed power to a hot wire the system freeks out