Temp gauge... argh

[MR 325]

My temp gauge has never worked. When the ignition is on "run" and the motor is off, the temp gauge will peg out at the red. Once I start the car, it goes back to nothing and stays there. I know for a fact that the car is running at the temps it should be, no problem there. I replaced the gauge sensor with a brand new one today and no luck.

Any insight? My next step is another cluster. After that, time to check my wiring I guess.

[Jason89i]

a little to vague. it would be helpful to know what you did, year of car to help diagnose. cheers, jason

[Mike B.]

Are you running an OBD-II to OBD-I conversion?

[static]

just get an aftermarket gauge - the stocker is almost useless anyway

[cahomey]

are you sure you have a e30 temp sensor?

[nando]

just get an aftermarket gauge - the stocker is almost useless anyway

yeah, that's the solution - something isn't working, so just hack the old one out and replace it with a cheap aftermarket gizmo.

[BDSax]

im guessing a bad gauge

[ldsbeaker]

SI board?

[static]

yeah, that's the solution - something isn't working, so just hack the old one out and replace it with a cheap aftermarket gizmo.

where did you see "cheap" or "gizmo" in my post? if he already is spending time chasing this problem, might as well upgrade the temp indicator to something more meaningful than the factory 'idiot' gauge.
IMO of course.

[nando]

where did you see "cheap" or "gizmo" in my post? if he already is spending time chasing this problem, might as well upgrade the temp indicator to something more meaningful than the factory 'idiot' gauge.
IMO of course.

this isn't the E36 - the gauge actually moves with the temp. the only difference is an aftermarket one has numbers. yay!

[MR 325]

It's an S50 in my 89. The sender is an E30 part and the SI board is fine.

[nando]

doesn't the temp gauge have the nut on the back for the ground wire?

[asubimmer]

shitty wiring prob

[lateapex31]

Any insight? My next step is another cluster. After that, time to check my wiring I guess.

Kinda backwards logic don't you think? Pull out your multimeter (you have a DMM, don't you? Anyone working on a car should have one), and check the resistance from the cluster to the sender and check for continuity to ground and +12V. It's probably a short that can be resolved by fixing it or at least pulling a new wire. Hold off on buying a new cluster....

[WillisE30]

You may have an issue at your C101 connector, I don't recall which wire(s) dealt with temp signal but that would be the first thing I'd check. I know I had a few wires incorrect when I started my swap the first time. I still haven't bothered to fix my oil level sensor wiring, but that's another story.