bosox_brit1970

i have a 96 escort LX over heating cos the fan won't switch on and the gauge wont movefrom C i have changed the temp sensor to gauge and the one next to for the fan and still not working .also if i jump the relay the fan comes on ,is there another temp sender and if so where is it?

rhandwor

Try another relay they can go bad. I assume you pulled the relay and made a jumper wire.

bosox_brit1970

i did'nt replace the relay just jumped it,but relay would not effect the temp gauge which is'nt moving no? i changed that before on a escort that was over heating and the gauge would go hot then

rhandwor

Pull the one wire from the sending unit and use a copper wire to the block the gage should peg if it doesn't its probably bad in the dash.
Click on escort and about 5 below this post their is a picture of the sending unit. Escort sending unit.Also check for fluid on the wire and clean with brake fluid.
What problem are you trying to correct gage or fan.

bosox_brit1970

did check the gauge sensor grounded it and it did peg so i changed that sensor.
and trying to fix both but not sure its the gauge not working showing engine cold there for not making the fan engage cos it thinks its cold no?

bosox_brit1970

i changed both on them in the picture...but is there another one like the one not circled and if so do you know where it maybe be?

rhandwor

http://fordfuelinjection.com/?p=28
This is a picture of a Ford EEC sensor it is two wire and always is near the thermostat or head. The computer system turns on the fan. It also should turn when you turn on the A.C. If it does swap the normal relay and this relay this way you can check them free.

bosox_brit1970

thank you i will try to find it tomorrow because i have already changed those two in that picture ,autozone says that fan and the ecc one are the same part. but i will look around to see if i can locate this 3rd sensor

mightymoose_22

When the engine is running the fan should come on if the sensor is unplugged... if it doesn't come on then you either have a bad relay or something bad with the computer (which is unlikely).
You say the fan comes on when you jump it so we know the motor is good. Assuming the new sensors you installed are good, then that leaves the relay...
I am not certain where you jumped it at, so if your jumper was after the relay then you still need to check it. If your jumper was before the relay then it has to be good.

Your problem could possibly be unrelated to electronics... I am not certain if the 96 model has the same part, but I know that up to 95 the thermostat housing sometimes fails and allows coolant to bypass the thermostat which creates an undercooling situation. In this case, maybe the fan is not coming on because the engine is not reaching operating temp due to the bypass?

When the engine has been running for awhile does the hose in which the sensors are installed get hot? What about the upper radiator hose? THey should be more than warm... they should get HOT. If not, maybe look into the housing issue.

I suppose there is also the possibility that the gauge is broken too...

tripletdaddy

It would be excessive cooling caused by a bypass of the tstat to the radiator resulting in the below normal engine operating temperature, or it would be premature cooling as it is cooling before it would normally be necessary as when the tstat would open. Not undercooling. That would be the opposite, resulting in the overheating of the engine. Eh?

But that does make one think maybe the tstat is stuck open or opening way too early, ie. too low of a temp.

bosox_brit1970

i'm jumping the relay from the underside of the plug.
and the hoses are warm so i know thats good and working

]

AzTumbleweed

If the heater core is clogged and the coolant circulation is completely stopped then the temp senders will never get warm enough to move gage or turn on the fan. I'd try bypassing the heater core and see what it does.

__________________
Nevada Tumbleweed

mightymoose_22

Well my thinking was straight but the wrong word escaped my fingers :P I never proof read... makes me look pretty silly sometimes

mightymoose_22

Well there is a big difference between "warm" and HOT. Do we know if the car is even reaching regular operating temp?

Does the fan come on with the sensor unplugged?

tripletdaddy

MM22, thanks. I just wanted to clear up that confusing point, but try not to sound picky.

AZ, I can see where you are going with that thought as Ford put those sensors where a blockage would prohibit a continuous flow of hot fluid. Ford came up with quite a Christmas tree arrangement of sensors screwed into that remote tube to the heater and the tstat housing with a 'Y' to the heater hose 'tree'. I agree with others here that there's a good chance of something maybe messing up at the tstat and anywhere through all of that crap. However, I'm not convinced the coolant won't get hot enough for the fan to come on with a blocked heater core. Heat will eventually get there either by heat transfer or by the pressure and flow from the pump. The sensors aren't that far from the head.

Bosox.., you should check to see just how hot the heater hose gets. If you can't hold it for a few seconds and it's similarly hot at the other heater hose that returns to the water pump and you have heat inside, I'm quite confident you're getting good flow through it.

So, did you get a good relay to get it to work?