The Stovebolt Site Forums The Shop Area The Electrical Bay Installing an electrical water temp sending unit

I removed the original electrical water temp gauge from a 51-52 GMC (also, it was positive ground truck..) It was an original gauge/sending unit setup!

I am going to use that electric gauge in my '50 Chevy 3600 restoration, which has been converted to a 12v system. Will any chevy temp sending unit do, or do I need to find a 6v sending unit? If so, it will require a Runtz on the gauge, just like the fuel gauge, right? I did post something about a month ago along these lines, but I don't think I was clear on what I was trying to do.

Any help appreciated. Thanks.

Not knowing GMC trucks, I assume when you say electrical temp sender it is not a bulb type setup.
To address the sender first: To start with, a temp sender does not care about the battery voltage, so 6 or 12 doesn't matter. Your problem is what they call the temp/resistance response curve. The sender changes resistance as its temp changes. You will need this curve in order to buy the correct sender unless use your old one. You can derive this curve with either of two simple tests if necessary.

The gauge is a different matter. I believe it is polarity sensitive but may be wrong. If it has three electrical lugs on the hookup side it should be no problem. I am again assuming that your will be using a 12 volt negative ground setup.

Beltfed, Yes my truck will be 12v negative ground.

Here's a pic of the GMC (on the right) and my stock '50 chevy on the left

Back of gauge clusters- GMC vs Chevy

Took a peek at your build album. Very nice.
I believe your temp gauge will not work with the neg. ground if it came from a pos. ground system. Test with a variable resistor, some wire, and a 12 volt battery will answer the question. You may elect to have it converted or rebuilt by an instrument repair shop. While your at it, both your clusters look to have a capillary tubes for oil pressure. You could also have one of those converted to electric.

Thanks... hopefully Google won't end up messing everything up like Photobucket did for so many people.

I should have researched the gauge issue further and tested before I decided to go with the GMC gauges. I've still haven't inspected the tank, so I'll pull the sender out and test with that. Thanks for your advice- I'll probably just go back with my original gauges if it doesn't work.

Thanks for the 'heads up' on google photo site. I don't post pics on this forum because of all the hassles on doing such. I'm going to look at the hosting site and might give it a try.