Temperature sensor problem

[jaysix]

What size is the piece that I had you take out??

Don't take this wrong, but a lot of folks don't understand pipe thread (NPT) sizes very well. If you do, that's great. If you don't, what is the diameter of the new sender and the old senders? I can figure out NPT from that.

3/8" is what the temp sensor and that vacuum piece are. That new one is 5/8" or bigger.

 

[jaysix]

I think you have the wrong sensor/switch. Do you have a guage or light, usually the single pole is for guage and the light is two pole switch.
The 2 pole should not be affected by sealer it is a separate circuit (unless you goop it all over probe) the guage single pole grounds through the threads so it may be a issue, they usually come new with sealer higher up on the threads.

I have the lights, no gauge.

 

[Big_John]

3/8"

If it measures 3/8" on the outside, it's a 1/8-27 NPT.

1/4-18 NPT is just over 1/2" and 3/8-18 NPT is 5/8".

 

[Big_John]

To give you a reference.. the heater hose connections are 1/2-14 NPT.

 

[Ross Wooldridge]

Perhaps the new sensor was misboxed...

 

[Big_John]

I'm wondering if the '76 water pump housing is different.

 

[jaysix]

Dorman - Champ Water Temperature Gauge - Mechanical 7-120: Advance Auto Parts

I found this one. If this will work, Im ordering it today and getting this land yacht on the road.

 

[Big_John]

I would suggest an electrical temperature gauge over the mechanical gauge you show. My reasoning is that the sender for an electrical gauge is going to be 1/8-27 NPT with adapters to make it larger if needed. The mechanical gauges tend to have larger fittings on the capillary tube.

I don't see any size listed for the gauge you've linked.

IMHO, electrical gauges are easier to install too. The capillary tube has to go through a fairly large hole in your firewall. You can't kink it either. An electrical gauge is one wire to the sender, one to power and one for the light.

Auto Meter 1436: Designer Black Water Temperature Gauge 2-1/16" Electrical | JEGS

 

[70bigblockdodge]

The two pole sender is for the "idiot" lights. One pole is for the cold light and the other is for the hot light. It does depend on ground through the block.

Did not know there was stuff out there with cold light, guess I'm not as old as I thought.

 

[rexus31]

Im going to say both. This new one is absolutely massive. I did find one for a Ramcharger that is 3/8" 18npt with the 2 prongs that should work, I hope.

The old one you removed, was it the closest to the filler neck?

 

[jaysix]

Went and bought an aftermarket temp sensor and gauge. Crisis averted.