Temperature Gauge Problem

[94blu1500]

The temperature gauge in my 94 1500 has never shown anywhere near the correct temperature with the original thermostat it would show 160* when the truck was running. i checked the temperature of the sending unit with a laser thermometer and it read 210*. i have tried three different sending units all with the same results, i grounded the wire and the needle moved all the way to the right side of the gauge. any help would be appreciated thanks in advance.

 

[tattooed4life]

Sounds like your cluster is bad. I am not sure if it is serviceable or not. I am doing a little searching now.....

 

[94blu1500]

i swaped in a different cluster this morning and got the same thing i dont think its the gauge.

 

[Marcos]

I am having the same issue, I check my computer water temp and its its not showing the correct temp on the gauge but its getting the right temp to the pcm. You change the temp sensor on the head already?

 

[94blu1500]

yep i've tried three different sending units (the one that came in the truck, one standard electric, and the last was a ac delco from the local dealership) every one does the same thing. mines the same way the pcm sender is right and the one for the gauge will not do right.

 

[///RAGMC]

You might want to try installing a mechanical temp gauge temperary just to see where your at. Also Ive seen a few places out here that will repair stock gauges but its not cheap

 

[KevinL1987]

Are you checking the temp of the sending unit in the head, or by the water neck on the manifold?

If anything I'm thinking you have some resistance in the wire between the sending unit and the cluster. Since you said you have tried new sending units, and a new cluster.

Also, It's the sending unit in the head that gives you the reading on the cluster, and the one in the water neck is for the ECM (Which controls how much/less gas to feed the engine) Just incase you didn't know.

 

[94blu1500]

Yeah I'm definelty checking the one in the head, I haven't tried anything in the last few days but I'm gonna get it sooner or later.

 

[94blu1500]

I just rememberd this thread on fsc
http://www.fullsizechevy.com/forums...mp-gauge-despite-normal-coolant-temp-pcm.html

cliff notes: a sending unit with slightly lower resistance was used to correct the gauge problem

i think i might have to try this

 

[bump530]

any update on this? my truck only gets up to 160 also. i think it started readin that when i changed t-stats one time. and im pretty sure ive gotten the 195 t-stats when ive replaced them. also, the guage only got up to around 110 or so when my failsafe t-stat failed open. i always thought it would run a lil hotter than that if it was stuck open