Temperature Guage Issue

[styles666]

Hi all. I recently purchased an 85 capri RS. It is in good shape, runs good. The only issue is the temperature gauge always shows cold. I know this can t be right. What should I be checking to correct this? Thanks.

[jrc347]

Well, the first thing to do is to go to the temp sending unit ( should be a brass looking 1 wire sensor on the intake manifold), take the wire off the sensor, then ground the wire to the intake while someone else looks at the gauge. I f the gauge pegs hot, then replace the sender. If it does'nt do anything, then the problem is most likely in the gauge or wiring to the gauge. Hope this helps.

[styles666]

Thanks for the quick reply. Does anyone have a picture of the motor to show the location of this brass sensor. I removed the air filter section and there are many single wire sensors in this area. I used to have the Haynes manual 14 years ago when I had an 84 RS. There is also a cylinder shaped part beside the carb with a blue wire and connector not connected to anything, and I don't see the male connector anywhere for it.

[jrc347]

The temp sender is on the drivers side of the intake Towards the very front of the intake manifold. It's right behind the first bolt on the intake.

[styles666]

Well I grounded the sensor and the gauge went up so I'm gonna get a new sender. Hope that cures it and thanks again for the help!

[bob85gt]

i you wish to test the sender unit , the notes i have say temp hot 10 ohms, temp cold 73 ohms. by reading the sending unit with the engine hot and cold and by using a resistor with the sending unit wire to grd you should be able to trouble shoot whats wrong.

[styles666]

Well bob85gt, that is useful info because I have installed the new sender unit and the gauge goes right up the the L on normal. Before I installed it I checked the Ohms on the old one (0)-no good. The new one was reading 200+(cold). Haven't checked hot Ohms yet. I'm wondering if I have the right part. The old one had a white ring (insulator). The new one has a red ring. They told me both parts are the same. They also have one listed for the car with a green ring....??? I've read over many cooling issue threads here and it looks like I'm in for some fun here...:-(

[Ltngdrvr]

Well bob85gt, that is useful info because I have installed the new sender unit and the gauge goes right up the the L on normal. Before I installed it I checked the Ohms on the old one (0)-no good. The new one was reading 200+(cold). Haven't checked hot Ohms yet. I'm wondering if I have the right part. The old one had a white ring (insulator). The new one has a red ring. They told me both parts are the same. They also have one listed for the car with a green ring....??? I've read over many cooling issue threads here and it looks like I'm in for some fun here...:-(

I just looked it up and the one we(NAPA) offer has the green ring, it is part # TS6628SB.

[haromaster87]

If you wanna make things easy you could just pick up a mechanical water temp gauge. They're cheap, easy, and more accurate in the long run.