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Discussion Starter #1
Hello,
We newly purchased our 66 Coupe. I drove it for the past couple of days and noticed that the temp guage barely gets past "C". It doesn't reach the normal area. Is this the normal area where the needle sits?
Will the guage work (Go to normal operation tem range) if I clean the contact or will I need to replace a sensor or the guage itself?
I will clean the connection with contact cleaner anyways but need to know if I should order any parts tomorrow before NAPA closes.

Thanks in advance.
Amir
How far does your temp guage go?
 

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How do the other gauges read? If they all read low, I'd say you have either a bad ground from the Constant Voltage Regulator to the dash pillar or the CVR itself is bad. If it's just the temp gauge reading low, you either have a bad sender (in the manifold), or a bad wire leading from it to the gauge.
 

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My temperature gauge barely goes past the line for C which(as my aftermarket gauge tells me) is 130 degrees. I'd say this isn't bad! However, if it NEVER goes into the "normal" area then there's a problem with your wiring...
 

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If it were me I would ad an aftermarket mechanical water temp and oil pressure gauge set. They are much more accurate so you can tell what your engine is doing.


69 Mach 1 427 Windsor
 

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It's also possible your thermostat is stuck or actually missing. The only way to know for sure is to have a look. I bought a truck that was the same way, in the middle of summer! Sure enough, no thermostat. The guage was correct.
Old cars tend to have their own "personality". Your guages will probably never read exactly like a car just like yours. they should be in the ballpark though.
Before you spend any money you might ground the sender wire on the intake. With the key on (engine off) the gauge should peg. At least you'll know the guage is functional.
 

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Discussion Starter #6
I believe that there is a single wire coming out of the sensor. If I understand you correctly, I should connect that to a ground (Engine Block) with ignition on and engine off. This should peg the gauge? If not that wire, maybe another piece of wire.

If that happens the guage is good and the problem is in the sensor or the wiring coming out of it. Correct?

I'll try that and will let you know.
Thanks for your help in all the questions that I have asked. You guys are all very helpfull and I appreciate that.

Amir
 

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Discussion Starter #7
The rest are all fine. Only this one. My old 5.0 Mustang always sat at 1/4 way in the normal, but at least it made it in the normal area. This one doesn't even reach the line. It barely leaves the "C". I want to make sure that it is accurate because this is going to be my son's car and I want to make sure that it works. So he doesn't over heat the engine.

Amir
 

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I know it's a long shot, but a friend of mine just purchased a used Neon. The darn thing never warmed up... and when she checked, it had no thermostat. That way the PO could hide the head gasket problem until it was way too late! I'm pretty sure you don't also have this problem ( I would like to think that there is only one idiot seller out there and you did not buy the car from him)!, but I wanted to give a heads up anyway!/forums/images/icons/smile.gif

Good luck!
 

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You are correct, ground that temp. sensor wire and the gauge should peg to the HOT side, with the key on acc., if it does then probably the sensor is inaccurate, I just finished some rewiring on my 66, and my new Autozone sensor pegs hot when my other mecanical gauge reads 180 degree's. I read in other posts that thoes after market sensors can be off as much as 25 degree's or so. The advice given was to try and get a new Ford sensor if possible, or get one from a reputable Mustang outfit, ie;NPD. Hope this helps. Good luck! James.
 

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All you're checking is that the wire is good and the guage is functioning (but not necessarily accurate). Grounding the wire should have the same effect as if the sensor was reading extremely hot. Make sure the wire is well grounded, the test is easier with a helper in the car to watch the gauge.
The thermostat is still my first suspect.
 

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Discussion Starter #12
ha ha ha.. That is Sneaky!!!

No, the person I bought this car from was pretty honest.

I will probably replace the Thermostat anyways.
It is cheap, easy to do and will give me a piece of mind.
Amir
 

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most gauges are inaccurate. get a Walmart "candy thermometer" for $3, warm car up with radiator cap off, and measure water temperature -should be at your termostat value usually 160 or 180 degree. if OK then use gauge as relative indicator or look further to get correct value (VR, wiring, new sensor).
 
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