81 carver aft cabin heat gauge problem

[doc232]

I have an 81 carver with twin mercruiser 470's. On one engine the heat gauges in the upper and lower station do not work unless I disconnect one, then the other gauge will work. Both engines have new sending units and both sending units are the same. Can someone help? thanks

 

[Tommyfmu]

Re: 81 carver aft cabin heat gauge problem

No expert here by any means, but assuming they should both be wired in parallel, perhaps the wires are backwards on one gauge. They would be polarity sensitive being DC. Also if they're Faria gauages, if you put a continuity meter between the positive sender feed and negative/ground, it should read about 110 ohms when hot, so see if you're getting a strong signal.

 

[doc232]

Re: 81 carver aft cabin heat gauge problem

Thanks, I'll give it a try