Temp gauge sender question

[Dawso]

I read on another forum recently that you should not use plumbers tape on the sender screw thread into the motor because the sender earths through the motor. Is that correct? Of course I used plumbers tape on mine and the gauge hardly moves. Any thoughts? Thanks in advance.

[Innuendo]

Certainly earths via the thread. They also should be a tapered thread so no need for plumbers tape for sealing purposes.
I assume you have the VDO can type of sender to suit a needle gauge?

[Dr Terry]

It's better to use a proper thread sealant rather than thread tape, but it sounds like yours is making an earth, so your problem may be somewhere else.

If the gauge is only moving slightly either the thermostat is not working, you have the wrong sender or the gauge is faulty.

The easiest test for the DIY/home mechanic is to disconnect the sender wire & get a 25 ohm resistor (if you car is HJ-WB) & connect the sender to ground thru the 25 ohm resistor. The gauge should read around half scale. If it does, your gauge is OK & you need the correct sender. If it doesn't, your gauge is faulty.

Dr Terry

[Dawso]

Thanks for your help, I'll remove the tape on the weekend. Hopefully not make too much of a mess.

[Dawso]

Is a 25 Ohm resistor a gauge you can buy? If so who sells them?

[Dr Terry]

Is a 25 Ohm resistor a gauge you can buy? If so who sells them?

A 25 ohm resistor is just a small electronic component worth less than $1.

I buy that stuff from Jaycar.

Dr Terry

[damienengland]

Is a 25 Ohm resistor a gauge you can buy? If so who sells them?

Something like this should work...
https://www.jaycar.com.au/27-ohm-10-...istor/p/RR3357