Another FJ60 over heating...well sorta

[BigSur]

Down here in TX it gets freaking hot...when i drive around without my AC on my trucks temp is right below the middle mark. But when i turn the AC on the engine temp goes from below middle to 3/4 on the gauge. Why? Is this normal? It doesn't go past the 3/4 mark though and that seems weird to me.

Thanks

 

[accasbel]

Valley of the Sun

I went wheel'n Monday, it was 105+, way too hot for my blood. Since we were stop-n-go, crawl'n along, the gauge was going wayyy up. On occasion with the AC running and the truck going slow or on idle, the gauge would climb up between the top marker and the red-zone. I'd then turn off the AC and the gauge would drop to or just below the top line. The oil temperature hardly ever budged.

When it's 105+ and I'm running around town with AC on, the gauge roams between 1/2 and 3/4.

 

[mpetersrx7]

Does your fuel gauge move at the same time? You may have the common problem where the 12v regulator on the fuel gauge which also supplies to the temp gauge needs to be cleaned or replaced. The add load on the alternator from having the A/C on may be enough to affect this. I know mine tends to act up more with more accesories on (ie A/C, lights, stereo).

To fix either repalce the fuel gauge or clean the contacts on back of fuel gauge.

Hope this helps.
Mark