OK, I only had my Autometer Water Temp gauge hooked up for a while now and I decided to hook both that one and the stock cluster temp gauge up so they both read instead of one or the other. This is how I hooked them up (sorry for the quality of diagram ha):



OK so I have them hooked up and tighten them down so they don't leak and I let the car warm up. I fill up the coolant resevoir tank up a little with water because I leaked some coolant out installing the fittings. Now usually the car would get to about 205 degrees on the Autometer gauge and about halfway on the cluster gauge. Well my Autometer gauge reads 150 degrees and the stock one about 1/3. I decide to go test drive to warm it up. I get on it kind of hard but the Autometer gauge stays at 170 degrees and the regular cluster gauge reads in between 1/3 and 1/2. It won't go past those temps on either gauges.

Now I noticed when I got back to my house and shut it down that I forgot to completely latch the hood, but that shouldn't make that much of difference with temps should it? Did I mess something up or should I not worry about it?

I'd probably latch the hood shut (really shouldn't make much of a difference) and drive it a while. If it continues to fail to warm up, your thermostat is probably stuck open and needs replacing. No biggie.


Brian

OK, I drove it to school today and it still wasn't warming up completely. On my way home though, the autometer gauge warmed up to 180 degrees (straight up and down on the needle) and the gauge cluster temp gauge was at operating temp (horizontal needle). So is 180 degrees where a stock thermostat should keep the engine temp? And if so, why do you think my autometer gauge, when it was hooked up by itself, was reading about 205 degrees?

Well now you're down to if the gauge is reading too cool, or if the motor is running too cool.

IIRC the stock thermostat is 195º. So, if you're running 180, then you're running cool.

I'm assuming the autometer gauge is getting good voltage and a good ground right?

My suggestion (or at least what I would do) is the following:

Turn the car on and just let it idle. See how high the thermostat goes until the fans kick on. If it goes up to around 200 and something, you're good.

Then, drive around, if the temp drops while you drive it around, then your thermostat needs replacing.

If the fans kick on and the gauge is still reading 180, then something's up with the gauge.

As a last resort to test the gauge, you could always take it inside, boil some water (no salt) and stick the end in the boiling water. (You might have to bring a car battery in with you, I forget how the wires go). It should read close to 212, plus or minus depending on your elevation and the crap that's in your water. If it still reads 180, get a new gauge.

Brian