temp gauge problems

[easyrider]

I asked about temp gauge problems a while back and was given a chart to follow as to what the problem might be and I followed it and found that the sending unit was good, the gauge pegged out when grounded, so it shows up good. What is happening is that the gauge is setting at bottom when cranked up, then once warm, the gauge comes up to about a quarter of the gauge and about half way to mid point temp. That is as far as it goes. I got my a/c working over the weekend and figured that with the extra pull and heat that the gauge would run hot without my fans on. Temp stayed about the same and never ran into the hot zone with or with out the fans on. So, my question is can anyone explain what is going wrong? I doubt that I have that perfect a cooling system that it never runs over a quarter cool. Since this all works off resistance, could the gauge be working but not working correctly? Any help or suggestions would be appreciated. Thanks!

[mikey531]

One way to check is when the engine is cold take off the cap and put a thermometer in the antifreeze. Let the truck run and see what the thermometer reads. If you want to get it hotter put a piece of cardboard in front of the radiator but watch your TEMPERATURE!

[mclairmo]

That's what my truck does, too, and I think everything is fine with it. It may be that this is where your truck normally runs.

[Longhorn Man]

if your "with a/c on" numbers are the same as your without a/c numbers, while you are moving.... then it's fine.
If it is while you are parked, then you may have an issue.

go to wall mart and get a cheap sun pro guage and hook it up to the other head. Look to see what it says verses the stock one.

[69GMCLonghorn]

I like Andy's idea, but keep in mind it IS possible that the actual temp only climbs a 1/4 of the way up the gauge. I started a "bragging" thread last week with a pic of my temp gauge. It was 104° outside and the gauge was at the first white line off of the "C". So it IS possible, but not be probably...