correct temperature sender for a 66 cuda

[Stagger]

hi, my gauges all work beside my temp one. i have a 66 cuda formula s.
i bought a new sender from ebay that should be for my cuda. i measure the resistance in cold 225ohm and in operation it has 33ohms. somewhere i read that the sender operate 73-10ohm.
do i get the wrong sender?
if i connect the the cabel from the sender direct to ground. the needle moves fast to hot mark. of course i switch off the ignition after it moves to hot to prevent a burned gauge.
please let me know the correct part nr.for the sender i have to use.

thanks and greetings from vienna

 

[cudajim]

You didn't specify exactly what your temperature gauge is doing when it's properly connected. Is your gas gauge working properly? If not you should suspect the dash voltage regulator being bad, a common problem.

 

[67Dart273]

All the Mopar gauges of this era use the same sender resistance. "Read your shop manual." LOL. There was a tester that provided test resistances. The are "about" 10-15 or so for full, 23--25 for 1/2, and 70-73 or so

L = 73.7 Ohms (empty)
M = 23.0 Ohms (1/2)
H = 10.2 Ohms (full)

This works for fuel, temp, and oil if equipped.

There is no need to go to ebay to get a temp sender. You should be able to get one from your local auto parts store.

There are several "troubles" that can cause these gauges grief

Bad connections anywhere in the system, the voltage supply to the instrument regulator. If you have a Ralley cluster, the regulator is built into and is part of the fuel gauge. This is also true of the earlier cars, not sure when they stopped this, 65?

The guage unit itself can be out of calibration.

Wiring in the sender line.........and of course the temp sender goes through the bulkhead connector.

If you go to Radio Shack and buy (example) a package of four 100 ohm, 1/2 watt resistors, you can wire all 4 in parallel. This gives you one 25 ohm resistor which should give you very close to 1/2 scale on the gauge. Leave it powered for about a minute to stabilize.

This at least will give you some idea of whether the gauge is anywhere near accurate.

The temp senders are a thermister. If you do enough Googling, you might be able to find a temp / resistance curve for those senders.

 

[Stagger]

only my temp gauge isn't working. the needle stays by Cold. i build in an rt-eng solid state VR because my stock one doesn't work this winter. mine was build in the fuel gauge. i have a ralley dash with a speedometer. know also my speedo works after i changed the driver board. my oil pressure also works like the ampermeter.

only the temp gauge doesn't move.
thanks for your great infomations. i will test it with a potentiometer or a 25 ohm resistor to look what happpens. if i connect the sender cabel to ground (0 ohm) it goes very fast to full scale. so i thing the gauge is ok.