Temp gauge

[xx88man]

So I am pretty sure my temp gauge isn't reading properly. Is there a way to test the sending unit?
Is there a way to test the gauge without pulling the dash apart? Thanks in advance

[Cuda Cody]

Tell me more about your engine.  I know there's a specific temp unit that needs to be used with the gauges and using the wrong one will make the gauge not read right.     I had it happen on my engine run stand a few times.

[xx88man]

Tell me more about your engine.  I know there's a specific temp unit that needs to be used with the gauges and using the wrong one will make the gauge not read right.     I had it happen on my engine run stand a few times.

It is the original 318 2bbl. The only things that don't appear original are the tiny radiator (maybe for a /6 car?), no shroud and I don't know if the 4-blade fan is original.

[DeathProofCuda]

My apologies, I know that I am probably bucking a forum custom by not first posting an introduction, but I saw that you weren't getting much traction on your question and thought I might be able to help out a bit.

To test your gauge:
- Have someone sit in the car with the key in the "On" position
- At your engine, disconnect the wire to the temperature sender
- Use a jumper wire to connect the temp sender wire to the ground side of your battery (do this only for a few seconds)
- If the gauge is working, your spotter in the car should see the gauge peg to the hot side when the wire was grounded.  If there is no movement of the needle, you have a bad connection or a fried gauge.

To test your sender:
Use a multi-meter to check the resistance in ohms between the stud and body of the  temp sending unit.  If I recall correctly, the resistance when cold should be in the neighborhood of around 80 ohms.  Then heat the sending unit up.  You may be able to use a heat gun directed at the sending unit if it is still installed in the car, but I've never tried it this way.  I have removed the sending unit and dropped them in a pot of boiling water.  Recheck the resistance when hot.  Again, if I am remembering correctly, the resistance reading when hot should be about 10 ohms.

[Chryco Psycho]

Welcome to the site from Panama  @DeathProofCuda
Thanks for contributing to helping members here 

[Cuda Cody]

   Welcome to the forum @DeathProofCuda   

[xx88man]

Thank you I will check these out that way. I appreciate your help. Welcome to the forum @DeathProofCuda it is a great place with members always helping each other out. You will be a great contributor I'm sure. Thanks again 

[DeathProofCuda]

Good luck with your troubleshooting.  Let us know what you find.

The suggestions I provided are pretty basic.  If you want to have a better understanding of old Mopar gauge operation and troubleshooting check out the Master Technicians Service Conference Reference Book 66-10.  I will try to attach a pdf copy.

You can also download the pdf or watch video copies of the original movies here:

http://www.mymopar.com/index.php?pid=441

These old tech reference movies are a hoot to watch and I've learned a ton from them.

[Slotts]

   Very nicely done set of instructions and welcome aboard! @DeathProofCuda

There is only thing I would like to add for the OP if you do find that the sending unit has failed. I found this by helping a friend replacing one with a repop sending unit that he had as a replacement. The repop read very high, pegging the gauge, after letting the engine warm up. The sending unit at full hot was show 0 Ohms resistance, rather than 10 Ohms resistance. The fix I diid was to insert a 10 Ohm resistor in line and that corrected that issue. You could use a 1/4 watt or a 1/2 watt resistor.

Jim

[xx88man]

Great info! Thanks Jim!   

[xx88man]

Results: I tested my gauge with a jumper wire and it appeared to be working properly. I changed the temperature sender I put in a Standard TS-17T   I only have driven it a short bit but it appears to be working properly. I didn't use a resistor. Thanks for the help