Temp guage question...what gives ????

[rod locker]

I have changed upper and lower radiator hoses, thermostat, and added fresh coolant. I have looked inside radiator and seen the coolant moving so the water pump is working. However, as soon as I starti up the temp gauge goes dirctly to 250 degrees. How does the gauge get its signal? Where is the sending unit located for temp gauge? What else could it be ??

 

[AdamR]

what motor ? Small blocks have the sender on the passenger side of the intake, BBs are on the water pump housing. Not sure were /6 is

 

[jaws]

Could be the sender wire is grounding some where.

 

[memike]

/6 is on the top in front of the valve cover

 

[67Dart273]

what motor ?

'xacly. And while you're at it, what year/ make/ model AND engine, "we" don't know if you're workin' on a 53 Dodge swap or a 2020 Pree *** conversion, 'er what


When you find the sender, remove the wire. Gauge should remain at cold. try grounding the wire, turn on ignition and it should head quickly for hot. Don't leave it on long. If it passes these two tests, you probably have a bad sender.

If it still heads for the hot zone when disconnected, you have a wiring problem. It's one wire from the sender to one terminal of the gauge, so you'd have a short somewhere. Most likely I'd say is something that got hot out in the engine room

 

[trapster]

It sounds like your dash regulator is not functioning correctly

does your fuel gauge work ?

check the voltage with a meter and the sending unit, with and without it connected.

 

[RedFish]

Wild needle swings are a symptom of a bad instrument voltage limiter. Simple tests with a ohm meter will prove the wiring and sender either good or bad.
It's easy to throw a little money at it too if you want. If you buy a new sender be sure you tell them you have a temp gauge and not a temp warning lamp since the senders are different.

 

[rod locker]

Sorry guys. I have a '74 Duster with a 318. And the fuel gauge along with the other gauges work fine. I have had the car now 3 years and it just started this all of a sudden.

 

[RustyRatRod]

Take an ohmmeter and ohm between the temp sender brass tip and ground. If you got continuity, put a new sender in it.