Temp Guage (1 Viewer)

[PITT94]

Hello all,
I have a question with troubleshooting my temp guage. This is for a 1980 FJ40 stock 2F. The other day my temp was higher than the previous day. It was at the 3/4 mark and the guage in the vehicle only has C, 3/4, and H. No signs of overheating just the needle being higher than normal. It did this for about a day and then the next evening with the engine cold the needle went straight to H on start up. Now every time I start it goes to 3/4 and then to H within 2 min.
I removed the cluster and cleaned the contacts and terminals and it still does the same thing. Could my water temp sending unit be bad or something else. All other guages work fine and again no overheating problems.
Any advice would help.

 

[BladeRunner80]

From what I have read, a majority of the people on this board find the stock temp gauge to be mostly worthless. If I were you, I would go down the your local auto parts store and purchase a decent aftermarket temp guage that actually gives you numbers to reference rather then a "L" and "H". They're pretty cheap (10-20 bucks) and its a lot cheapter then putting faith in a faulty gauge that could possibly lead to more trouble if your engine isn't cooling right.

 

[cruiser88]

get new aftermarket guages

 

[splitshot]

X2, My guage starts at 1/4 (when the ambient outside temp is in single digits) and tops out at just over 3/4. I changed the sending unit, seemed to fix the problem, but just for a couple of months. In my opinion, go with at least a back-up unit.

 

[bsevans]

Hello all,
I have a question with troubleshooting my temp guage. This is for a 1980 FJ40 stock 2F. The other day my temp was higher than the previous day. It was at the 3/4 mark and the guage in the vehicle only has C, 3/4, and H. No signs of overheating just the needle being higher than normal. It did this for about a day and then the next evening with the engine cold the needle went straight to H on start up. Now every time I start it goes to 3/4 and then to H within 2 min.
I removed the cluster and cleaned the contacts and terminals and it still does the same thing. Could my water temp sending unit be bad or something else. All other guages work fine and again no overheating problems.
Any advice would help.

It sounds like your temp sending unit has failed. I would go to NAPA or the like and get another sending unit.
This is exactly what happen in my '78 and a new sending unit fixed the problem..

 

[PITT94]

Update

Changed the WTSU and the problem is fixed. Thanks for the information.