Newbie here,

I am doing some troubleshooting on my 78 water temp gauge. I've been through the standard procedures of grounding the sending unit wire (did not peg the gauge), did a continuity check of sending unit wire, snd checked the resistance at the sending unit (seemed normal). I replaced the gauge with a new one, but the one i recieved just came with a white plastic piece that does not seem to be a resistor. It seems to have something internal. Reading across the left and right lugs on the gauge, I am getting 85(ish) ohms which after some research seemed to be close to OEM. After intalling the new gauge, it is not reading correctly and stays steady just over the 200 degree mark, no change if grounded out. I disassembled everything again with no luck on standout issues. Also, after the last install, I melted the top center "line" on the printed circuit board (newly replaced) as a result of incorrect locations of the insulated washers under the gauges.

My questions are:
Is it likely that my new gauge is bad from stock? Is there any good variable resistor set ups out there that can mimick what Wilcox used to sell?

Does anyone know where I can find the information on the exact location for the insulated washers?

Should i save my pennies and swap to Dakota digital?

 

Were there any instructions with the gauge? Have you called the vendor to ask these questions?

 

Unfortunately, no instructions with the gauge. When I called they were surprised to hear there was 1 in stock. I am having difficulty finding info as all the diagrams and referenced info is mostly from Wilcox and they are no longer around.

 

Hopefully, the sending unit was NOT installed with [insulating] teflon tape around the threads. The metal case of the sending unit needs to connect to electrical ground [engine block] to complete the circuit, so only pipe thread 'dope' should be used to seal that joint. The threads will still make enough contact through the pipe dope.

 

Thanks for the info. Im not the one who installed it but I will check when I get home. My sending unit is installed on the intake but I assume it is the same either way.

 

Yes. The metal case on the sending unit must make electrical contact with the metal to which it is assembled.