Temp gauge always reads low - what's the right resistance for the sender?

[davepl]

My 70 402 has gauges and the Temp gauge always reads down near Cold. Not -at- cold as in not working at all, but very low.

The connection is OK, but I'm wondering what the ohm range is supposed to be on the sender. If the truck is up to operating range (let's say 195) what's the ohmmeter supposed to show? If someone knows that value, I can check it to find out if its the sender or the gauge.

Thanks for any help!

Dave

[fixit-p]

I don't know the specs on the sender but if too much sealant is used it could lead to high resistance between sender body and engine which would be additive to the resistance of the sender. So I would check resistance between sender body and engine.

[cdowns]

having sender in the intake manifold at times leaves the sender not in contact with coolant causing bad readings

[davepl]

Thanks! I'll check the sensor-ground differential and report back. Good ideas!

This one is in the head. On my 427 2+2 (Impala) it's in the intake. Had to drill and tap it when I replaced the intake... $40 for the bit and tap, cost more than the intake!