Temp gauge broken???

[Joker Z28]

Ok the guage on my dash does not work anymore.
It just sits down the lowest point it can go and never moves, even after driving.
I recently replaced both coolant temp sensors, (the one that goes into the head, and the one below the thermostat housing area.) What could be the problem now?

[Joker Z28]

bump

[chris]

Sounds like a wiring issue. Do you have a scanner to look at the pcm temp gauge to ensure its not over heating?

Ill get ahold of a diagram for you tomorrow

[Joker Z28]

Sounds like a wiring issue. Do you have a scanner to look at the pcm temp gauge to ensure its not over heating?

Ill get ahold of a diagram for you tomorrow

No I don't have a scanner, right now im just driving and praying that it doesn't over heat haha.

That would be sweet, I dont know how the wiring would just mess up like that. I had the car for 2 years without any problems.
I guess shit happens.

[Huff035]

did it work at all right after you put the sensor in the head? because at one time i put one in from autozone and it shit out pretty much right away. i went to the dealer and bought the next one, been fine ever since.

[Joker Z28]

It worked for a few minutes (I think)
The bar was moving up very slowly but after I turned off the car it never worked again.

[Huff035]

Where did you get the sensor from? If it was anywhere but a GM dealer I would go and get one from a dealer. It will be easy to try and you wont have to chase down the wiring issue. I wold almost bet that is your issue.

[Joker Z28]

The first one I replaced was from Advance AP, the other one I replaced was from Autozone.
Kinda sucks im out $40 bucks and now I need another $40.

[Huff035]

$40? Just replace the one in the head first. Dont buy both yet.

[Joker Z28]

Arite good to know.
I will try to get it done this week.

[Joker Z28]

So I am guessing the one next to the intake manifold connects to the PCM while the one in the head is for the gauge or do I have it the other way around?

[Huff035]

I know the one in the head is for the guage, I'm not 100% on what the other is for sorry.

[ksmyss]

the head sensor is for the gauge. the other is in/on the waterpump

i broke my head sensor and replaced it twice and both were jacked up so i replaced the sensor in the water pump with a dual purpose sensor so it controls both the computer and gauge.

[Joker Z28]

Where did you get a duel purpose sensor from?
I know one is for the PCM and the other for gauge.

BTW do you have a ford 8.8 on your car?

[ksmyss]

Where did you get a duel purpose sensor from?
I know one is for the PCM and the other for gauge.

BTW do you have a ford 8.8 on your car?

i got the sensor/sender from gm.

Part No Description Cost
10096181 PCM/Gauge sending unit
12102748 Connector pigtail (incl. terminals)

i used to have a pic of the way to wire it. the harness/pigtail only has white wires.

Black=PCM sensor ground
Yellow=coolant signal to PCM
Dark Green=to Gauge

yes, i have an 8.8 under my car.

[Joker Z28]

Nice, what all did you have to do the make the 8.8 work?

[ksmyss]

Nice, what all did you have to do the make the 8.8 work?

i machined 2 collars to mate the 10 bolt axle tubes to the 8.8 axle tubes. the 8.8 tubes are bigger. welded a brace on the top and bottom just for extra insurance and made a torque arm mount.

the 8.8 28 spline diff will accept the stock 10 bolt axles. that is what i have been running since i got a free 8.8 posi. have since got custom 31 spline moser axles and a 31 spline trac loc. i just need to pull the rear out and have it all put in.

[Joker Z28]

I need more ideas, I replaced the head sensor with an OEM one from a GM dealership.
Now it acts very weird, sometimes it temp gauge's needle just sits at the very bottom and doesn't move. Other times it would move up just a little bit and stay right on the 160 line.
I checked the fuse for the dash and it was fine.


Is it possible I just need to recalibrate the needle?
When I put on the white gauge faces I did take the needles off then back on.