Technical Fiat Uno electrical issues

[capers626]

Hi all,

I'm having some electrical issues on my 1993 Fiat Uno Mk2, they're affecting a number of functions including hazard warning lights, heated rear window, horn and interior light. Plus the in car radio/cassette. All are currently out of action .

I've checked all fuses which are good and substituted the three pin blue coloured flasher light relay, which slots on the side of the fuse board, with no change.

One thing I have noticed is that the direction indicators work on both sides (front and back) ruling out any problem with the bulbs. Perhaps this indicates the hazard warning switch itself is faulty?

With the horn there is the possibility that the two copper strips under the steering wheel have become flattened, breaking contact. The connections to the horn at the front of the engine may have corroded too.

Otherwise, it will be a case of using a multi meter to check connections for power. Unless mistaken, horn and hazard warning circuits are constant live feeds even when ignition is off.

Any thoughts or feedback welcomed.

Cheers,
Andy

 

[bugsymike]

Hi all,

I'm having some electrical issues on my 1993 Fiat Uno Mk2, they're affecting a number of functions including hazard warning lights, heated rear window, horn and interior light. Plus the in car radio/cassette. All are currently out of action .

I've checked all fuses which are good and substituted the three pin blue coloured flasher light relay, which slots on the side of the fuse board, with no change.

One thing I have noticed is that the direction indicators work on both sides (front and back) ruling out any problem with the bulbs. Perhaps this indicates the hazard warning switch itself is faulty?

With the horn there is the possibility that the two copper strips under the steering wheel have become flattened, breaking contact. The connections to the horn at the front of the engine may have corroded too.

Otherwise, it will be a case of using a multi meter to check connections for power. Unless mistaken, horn and hazard warning circuits are constant live feeds even when ignition is off.

Any thoughts or feedback welcomed.

Cheers,
Andy

Many different issues.
Re the hazard lights, I have often found taking the switch out and giving it a good spraying with electrical cleaner (not WD40) work the switch multiple times, reconnect and fixed the problem.
Wiring at tailgate hinge can upset many things and I have also found issues with the aluminium connectors on the rear lamp units on those models.

 

[capers626]

Thanks Mike. I will take a close look and clean the hazard warning switch. Tailgate wiring is not something I had considered so will investigate. The aluminium connectors, not so sure, as the direction indicators are all working.

 

[bugsymike]

Thanks Mike. I will take a close look and clean the hazard warning switch. Tailgate wiring is not something I had considered so will investigate. The aluminium connectors, not so sure, as the direction indicators are all working.

One of my daughters had intermittant issues on rear indicators which was caused by the aluminium connector plug connection on the lamp unit, it just gets white powdery on one connection, cleaning only worked for a while, but a good s/h lamp unit solved that problem.

 

[capers626]

Yes, I've had a similar issue in the past but all direction indicators working correctly at the moment - except in hazard warning mode.

 

[bugsymike]

Yes, I've had a similar issue in the past but all direction indicators working correctly at the moment - except in hazard warning mode.

Try what I mentioned re the Hazard switch as they are only used on odd occasions they do dry out the contacts, so electrical switch cleaner and working vigorously may make a difference.

 

[capers626]

Yes, as I mentioned earlier, I will try and clean the hazard switch contacts, they do sound a bit dry when the switch is pressed.

 

[The Panda Nut]

Tail gate contacts on this can also get dirty affecting the heated rear window, contact cleaner and or some brass leaner on both parts while the tailgate is open may help.

 

[capers626]

Thanks for your advice. It could well turn out to be part of the solution. I will need to buy some electrical contact cleaner to see if it makes any difference.

 

[portland_bill]

Check all the body earth points. A bad earth at a multi-connection will have current trying to flow back along all the other circuits.
Many years ago, a friend had an Uno, suffered multiple electrical issues, caused by a bad earth connector, somewhere near the battery, I believe, but definitely on an inner wing under the bonnet.