ed,s64

Last week l needed to boost my car and l noticed that the temp gauge was pegged to the right. I figured it go down to normal position but it didn,t.But when l turn on my heater fan to low then med. the gauge would drop to normal readings. When l put the fan onto high the temp would peg all the way to the left.The car runs at 190* so no over heating issues.Any sugestions. Thanks P.S. Thanks to the forum member who sugested to Frankie the fink about putting the garage door opener from the middle to the side. Did this today and gained an extra 2 ft. and the door works as normal.Thank You Elio

65GGvert

There's no connection to the fan circuit except the grounds. The temp sensor is grounded at the intake, so that should not associate with the fan either. Make sure the sensor is grounded good via the threads and check the connections at the dark green wire going through the bulkhead connector. The fan motor is grounded (along with the wiper motor) at the starter bolt, I don't know of any reason that a loose ground there would cause a temp gauge problem, but take a look at it. Check the connections at the temp gauge. That's about all I can think of.

ed,s64

Thanks i,ll take a look at the bulkhead, sure don,t understand why the temp needle would move with the running of the fan motor.

65GGvert

Me either, it has 12v on one side and ground (through the sensor) on the other. You can always run a long wire from the green on the gauge to the top of the sensor and bypass all the wire and connector to see if it's a problem anywhere between. The only logical reason to me is if the sensor ground is not good at the threads and the voltage is feeding through the fan ground instead. Make sure you post what you find.

ed,s64

Back from dinner with the wife, now l can head into the garage and see what l can find.It,s odd that a boost would knock my temp gauge out of wack. Was working good before the boost.

ed,s64

Well that was a quick fix. After checking the grounds at starter,blower and temp sender l pulled off the harness at the bulkhead (last original harness to change) did a quick visual, reinstalled it. Put the key in and turned it and presto. The guage reset itself and when turning on the fan there was no movement on the gauge. I can go to work this week knowing another issue has been put to rest. Seems the list never stops.