1986 Pontiac Fiero FUEL & TEMPERATURE GAUGE

MATT P.

MEMBER
1986 PONTIAC FIERO
6 CYL
2WD
AUTOMATIC
119,000 MILES

Both my fuel & temperature gauge stop working at the same time. The temperature gauge is resting below lowest temp reading and the fuel gauge is highest the needle will go. A few days later the speedodomer gauge stoped working as well. What could be causing all these problems at the same time?
I took the dash apart and all the wiring looks good and can't see any burns on the ciruit boards. Also something is causing all my lights and gauges flirter at night. I'm out of ideas what to do next.

1 Reply

HMAC300

MECHANIC
48,601 POSTS

First thing to do is disconnect the coolant temp switch and turn the key on and grond the temp sensor wire out. If the guage goes up then your sensor is bad. Then go to your fuel sending unit and disconnect the wire. If the guage goes down then it's the sender there. Make sure that your battery cables are clean and tight to stop the flickering of your lights. Check your fuses though to make sure you haven't blown a fuse as well. Your speedo has a sending unit off the trans that may be bad, so you'll have to try replacing that as I don't know the hom resistance for that.