I have a 4 core desert cooler radiator with twin derale puller fans cooling my big block, with a 180 thermostat. My temp gauge is an auto meter phantom electric with the auto meter sender in the manifold port on the passenger side. When it warms up, the gauge reads about 195 (the hash mark between 180 and 210) and usually fluctuates between 195 and 215 while driving. I just put in a new summit electric fan sender, 200 on and 180 off, and the fans do not come on until about 220 and turn off at 195. My question is which temp should I believe, and how do I get my temp gauge to read more accurately? Thanks for the help.

I'm not a big fan of electric gauges, i don't find them very accurate, machanical gauges are mor relieable. The best way to check your water temp. is to let it warm up and record you gauge reading.... carefully remover the rad cap and place a meat thermometer into the water and record the reading and see if there's a difference in the readings. If your able to use more then one thermometer to chesk the temp then do so.

It's a common problem in electric gauges but can be fixed. Go to Radio Shack and pick up a 0-100 ohm pot and wire it in series with the temperature sensor wire. Warm up the engine and trim the pot to make the gauge read correctly. I did this on a street rod not too long ago where the owner threw lots of cash into a new radiator and puller+pusher fans and it still "overheated."

For me, replacing the sensor has never worked to cure an over-temp reading gauge.

Trim pot, meat thermometer. I've done it also................ DON'T GET BURNED!

Interesting.....I have that same gauge, and with three different big blocks in my car, I have always had a problem with it running hot, or so I thought....same exact readings as Nick mentions. I have been thru radiator changes, regular fans, electric fans, everything. I guess I never gave a thought to the gauge as I bought it brand new, it's not like it was already in the car. Im going to try this also and see what's up. Maybe I'll try a mechanical gauge, I have one available just as a checker. John

It's a common problem in electric gauges but can be fixed. Go to Radio Shack and pick up a 0-100 ohm pot and wire it in series with the temperature sensor wire. Warm up the engine and trim the pot to make the gauge read correctly. I did this on a street rod not too long ago where the owner threw lots of cash into a new radiator and puller+pusher fans and it still "overheated."

For me, replacing the sensor has never worked to cure an over-temp reading gauge.

Can you give me a link to the part you're talking about? I don't know what it is but I still want to give it a shot.

thanks

http://www.allelectronics.com/cgi-bin/item/LTP-100/470/100_OHM_POT,_LINEAR_TAPER_.html

Likely you will use the center and one end terminal, but verify with an ohm meter before installing.

After the adjustment is complete, you can either make up a resistor pack to match the pot or or leave the pot in place.