Short in instrument cluster (Page 1/1)
1MontanaFiero SEP 26, 09:26 PM
I have an 86 Fiero GT and I’ve been busy troubleshooting an electrical issue in the left turn signal circuit. Bulbs out, I have isolated it to the cabin side of the firewall, with the steering column harness disconnected.

There is a short to ground that disappears if I disconnect the connector from the instrument cluster (turn signal indicator bulb has been removed). Reappears upon connection.

I have a cluster from an ‘84 available. Will my gauges go right in that one? Is the printed circuit plastic wrap on the back the same? Can I make this work for me? Sure hope I’ve isolated this thing.

(Symptom was no front turn signal lights, except for the indicator, which was steady on all the time.) Traced the entire front harness and took it out of the picture.

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1986 SE 3.4L Pushrod swap, 4spd
1987 GT 2.8L Auto
1986 GT 2.8L, 4Spd factory wingless, factory sunroof delete
1984 SE 3800, Auto

sanderson231 SEP 27, 05:54 PM
The copper foil on the plastic can come loose where the plugs insert and create a cross connection. That's the first place I would look.

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formerly known as sanderson
1984 Quad 4
1886 SE 2.8L
1988 4.9L Cadillac
1988 3800 Supercharged

theogre SEP 27, 06:28 PM
The (symptom) at bottom are often iffy front bulb/socket problem.
See my Cave, Sneak Path
Unless you pull C100 near gas pedal then iffy front bulb can still be a headache.

Big plugs on back of dash have copper on the "board" that get loose and bend and can short out when you remove and reinstall the plug(s).
use a mirror or camera to look at the back of dash.
1MontanaFiero SEP 27, 11:57 PM

quote
Originally posted by theogre:

The (symptom) at bottom are often iffy front bulb/socket problem.
See my Cave, Sneak Path
Unless you pull C100 near gas pedal then iffy front bulb can still be a headache.

Big plugs on back of dash have copper on the "board" that get loose and bend and can short out when you remove and reinstall the plug(s).
use a mirror or camera to look at the back of dash.



Thank you so much. I was troubleshooting down a rabbit hole, because I removed the wrong bulb out of the dash. I even removed the dash, which tested fine. After reading your "Sneak Path" troubleshooting notes, It took me a mere 30 seconds to find the bad 1157 socket with no internal ground. Wiring was good. Now to put things back together. At least I was able to clean behind things.