aftermarket coolant temperature gauge install
 

Just bought a 1983 RX7 and the temperature gauge isn't working. After figuring out that my temperature sending unit was sending resistance and the wire plugged into it had volts I decided I would install an aftermarket temperature gauge. I heard they are more accurate anyways, even though it would be nice to have all the stock gauges working.. not sure how easy it would be to trace the gauge voltage wire or replacing a stock gauge would be. The temperature probe on aftermarket gauges are much to big to fit where my sending unit goes. Is there any other way to install an aftermarket gauge besides using an adapter to place the probe in the radiator hose? And another question, would a twenty dollar equus gauge be decent enough for a daily driver, or is it actually worth it to spend forty or fifty on a nicer brand?

There are adapters for the radiator hoses but you have to cut the hose, obviously. You have to make sure you have the correct size probe to fit the adapter as well.

Drill and tap the water pump housing at a convenient spot. I prefer at the rear near where the thermostat neck begins.

Placing the temp sensor in the rad hose is fairly pointless as that puts it after the thermostat. In the event of a thermostat failure or coolant leak, the gauge would not read.

The best spot for a coolant temp sensor is on the back of the coolant neck of the engine. You'll see a dimple back there, and that's what you drill and tap for the gauge. As for brand, I usually get autometer gauges and have never had a problem with them. I've never heard of Equus.

Beat me to it while I was typing away! :blush:

I ended up putting on an electronic temp gauge because i was told it would hook up to my water temp sending unit and seemed the easiest way. The gauge works, but the hash marks are somewhat odd.. starts at 100, then is followed by a 150, 180, 210 and then it jumps to 280. There is a halfway mark between 210 and 280 which is right where it sits. Not sure exactly what temperature that is supposed to read as considering halfway between 210 and 280 would be 245... I attached a pic
https://cimg7.ibsrv.net/gimg/www.rx7...5b8b556566.jpg

Well just make sure the needle stays between the 180 and slightly under the 210 mark. Normal operating temperature is 185 to 190, but can vary if you are in a very hot environment. If my car ever touches 200 I pull over and see what's wrong, and I live in Florida.

This is where it sits after warming up
https://cimg4.ibsrv.net/gimg/www.rx7...265c02da1b.jpg sometimes it will go higher. Im going to start replacing parts to get the temperature down hopefully. Thanks for the advice everone

Dang. Hopefully that's not accurate. Does the car have an electric fan or the stock fan?

Im hoping that the 210 hash mark is the last small one. It is the stock one I believe. I spun the fan after it was warmed up and it seems tight, it only spins about half a rotation, that means the fan clutch is good I think. It looks like the shroud is in tact under the front bumber. At highway speeds it gets hotter. So I'm guessing its the thermostat water pump or radiator? That or the oil cooler maybe?

I should sell your silicone tits for your Bull.(chuckle!!)
That gauge is useless.
Spend 50 bucks and get a digital gauge or something that has a good readable sweep.
You have to Stare at that thing to get a "ballpark idea' as to what the temp is and you may as well just place your hand on the engine and say "Ow...too hot!!"..

NO offense but if you think that Nickel and Diming the Reliability of this type of car will allow you to squeak by it will only cost you in the long run.
Knowing the temp would be a bonus at any cost.It could save you a couple grand.

+1 to styx.

None taken I agree. I wanted to get a nicer one but this was all they had. Im going to have to order one online. Do you have any recommendations for brands? That was one of the original points of this post, but I was being inpatient so I bought this shitty gauge

As you've proved, the gauge hooks up and moves. But it isn't accurate because the gauge and sender have to be paired relatively closely to work. As you have it hooked up, the numbers are meaningless.

You can use it like the stock gauge that just has C and H.
Note where it normally sits when idling. That's probably pretty close to 180 when the thermostat opens.
It can fluctuate above that a little while driving hard.
Way above/pegged means something's broken.

Yeah at this point I just want to buy a different gauge. Idk where Styx is finding full sweep electric gauges for 50 bucks though. The only ones I found were made by pro sport and glowshift. All the autometers were 170+ is glowshift a dependable brand?

I got this one and Like it as it has the meter sweep and the Digital readout.,
MaxTow Water Temperature Gauge

The thing about these gauges are they can be adjusted for light separate from the dash lighting,so it can be mounted where you would normally not have a good eye to the gauge.You can also turn the illumination off completely if you so desire.
Mind you that the gauge I am recommending is NEW,but you can get good stuff in the Sec Gen Parts section used,and half the cost.