1986 IROC gauge issue
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Junior Member
Joined: Jul 2016
Posts: 47
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From: Rosenberg, Tx
Car: 1986 IROC Z28
Engine: 305 TPI
Transmission: auto
1986 IROC gauge issue
Hi folks, I had my tach repaired in the process of restoring my 86 but think I have discovered more problems with my gauges. My fuel gauge seems to hang around half way up but fluctuates just a little back and forth (I have new pump, hanger, sending unit - everything) but the car sat out in the sun for prob 8 years before I rescued...it ran dry on me and when I filled up it stays around that same spot, just a little movement.
the temp gauge was acting a little squirrely when I drove the other day, seemed like it started running hot when I had gotten off the freeway and took an abnormal time to climb back down.
I am wondering if I should pull the cluster apart and rotate needles around to free things up ? I don't want to mess anything up but wondering
could the needles just be stuck from not being in use for a while ? I am just not sure where to hunt first...I have read the wiring posts through searches but since gauges seem to operate "some" I don't think it could be a ground/wiring issue.
thanks for any pointers you can give.
the temp gauge was acting a little squirrely when I drove the other day, seemed like it started running hot when I had gotten off the freeway and took an abnormal time to climb back down.
I am wondering if I should pull the cluster apart and rotate needles around to free things up ? I don't want to mess anything up but wondering
could the needles just be stuck from not being in use for a while ? I am just not sure where to hunt first...I have read the wiring posts through searches but since gauges seem to operate "some" I don't think it could be a ground/wiring issue.
thanks for any pointers you can give.
Last edited by Lethalv6; Jul 13, 2017 at 11:25 AM. Reason: addition
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Joined: Jan 2006
Posts: 3,341
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From: Mooresville NC
Car: LOWERED ♦ CRIMSON METALFLAKE
Engine: ► 400 KUBES ◄
Transmission: 765R4
Axle/Gears: EATON POSI 4.56
Gage Rage
Here’s how to test the fuel gage.
Remove the sender wire going to the gage.
Tape the bare end of the sender wire and put it aside.
Use a potentiometer with a value of 100Ω or the closest you can find.
Connect one end the potentiometer to the gage from the location you removed the sender.
Connect the wiper of the potentiometer to ground.
Turn the key to RUN.
Slowly adjust the potentiometer from 0Ω to 90Ω.
If the gage is bad it will exhibit the problem you have.
If the gage is good it will display a smooth transition from one end of it’s range to the other.
Therefore the problem is with the sender or wiring going to it.
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Here’s how to test the temperature gage.
Disconnect the green wire from the temp sensor.
Clip in a potentiometer with a value of 200 ohms or the closest you can find
from that wire to the ▬ battery terminal.
Turn the key to RUN.
Now remember, these gages are intentionally made to respond slowly to prevent them from wiggling to road undulations.
Slowly adjust the potentiometer from min to max.
If the gage is good it will display a smooth transition from one end of it’s range to the other.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing !
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Don’t Fuss Paintin’ Your Back Bumper, Cause B4 The Race Is Over I’m Gonna Be Pushing You Out Of The Way
Remove the sender wire going to the gage.
Tape the bare end of the sender wire and put it aside.
Use a potentiometer with a value of 100Ω or the closest you can find.
Connect one end the potentiometer to the gage from the location you removed the sender.
Connect the wiper of the potentiometer to ground.
Turn the key to RUN.
Slowly adjust the potentiometer from 0Ω to 90Ω.
If the gage is bad it will exhibit the problem you have.
If the gage is good it will display a smooth transition from one end of it’s range to the other.
Therefore the problem is with the sender or wiring going to it.
▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
Here’s how to test the temperature gage.
Disconnect the green wire from the temp sensor.
Clip in a potentiometer with a value of 200 ohms or the closest you can find
from that wire to the ▬ battery terminal.
Turn the key to RUN.
Now remember, these gages are intentionally made to respond slowly to prevent them from wiggling to road undulations.
Slowly adjust the potentiometer from min to max.
If the gage is good it will display a smooth transition from one end of it’s range to the other.
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Happy Racing !
◙◙◙◙◙◙◙◙◙◙◙◙◙◙◙
Don’t Fuss Paintin’ Your Back Bumper, Cause B4 The Race Is Over I’m Gonna Be Pushing You Out Of The Way