Cooling System Problem

First time here and first glance says this is the place to ask this, so here goes:

I have a 1995 Contour that blew a head gasket. Had Ford replace the cooling system fan fuse per recall, supposedly. They also told me the gasket was blown. Stripped it down, replaced the gasket, and rebuilt it. Then found what is believed to be the root cause of the blown gasket: the water pump. The water pump had a blown out freeze plug. Replaced that and everything seems to be running fine. Now for the problem: the temp gauge in the dash never registers anything, and the cooling fan never kicks in. The really wierd part is that if I remove the wiring harness from the temp sensor in the thermostat housing, the fan kicks in right away. I am at a loss for what could be the problem. We double checked all the wiring harnesses that were disconnected and all the other ones we could see but couldn't find a problem. Any ideas would be appreciated.

Thanks in Advance.
T.

First time here and first glance says this is the place to ask this, so here goes:

I have a 1995 Contour that blew a head gasket. Had Ford replace the cooling system fan fuse per recall, supposedly. They also told me the gasket was blown. Stripped it down, replaced the gasket, and rebuilt it. Then found what is believed to be the root cause of the blown gasket: the water pump. The water pump had a blown out freeze plug. Replaced that and everything seems to be running fine. Now for the problem: the temp gauge in the dash never registers anything, and the cooling fan never kicks in. The really wierd part is that if I remove the wiring harness from the temp sensor in the thermostat housing, the fan kicks in right away. I am at a loss for what could be the problem. We double checked all the wiring harnesses that were disconnected and all the other ones we could see but couldn't find a problem. Any ideas would be appreciated.

Thanks in Advance.
T.
Hi zombie13

there are two temperature sensors in the thermostat housing, the one to the coolant temp gauge is under the housing and is difficult to see, the one on top of the housing is for the engine managment system. Remove wire from sensor and ground/earth it and the gauge should show hot, if this works then the sensor need renewing.

best of luck.

Hi zombie13

there are two temperature sensors in the thermostat housing, the one to the coolant temp gauge is under the housing and is difficult to see, the one on top of the housing is for the engine managment system. Remove wire from sensor and ground/earth it and the gauge should show hot, if this works then the sensor need renewing.

best of luck.

Thanks, I will try that. I replaced the EMS sensor and it didn't make a difference. Question tho, would the one on the bottom of the housing cause the fan not to work too?

Z

Hi Z

I'm not sure if the temp sensor activates the cooling fan or not but you should make sure gauge works first to determine if engine is running at correct temp. Some vehicles have another sensor screwed into radiator that activates the fan. Have you tried running engine while stationary for a while to get it hot to see if fan will run? Does the fan run when A/C is used? it should. Let me know how it goes.

E.

Hi Z

I'm not sure if the temp sensor activates the cooling fan or not but you should make sure gauge works first to determine if engine is running at correct temp. Some vehicles have another sensor screwed into radiator that activates the fan. Have you tried running engine while stationary for a while to get it hot to see if fan will run? Does the fan run when A/C is used? it should. Let me know how it goes.

E.

Have not had a chance to try anything yet. I did run the engine for about a half hour and neither gauge or fan worked. Tried the heat to see if the coolant was moving thru the system and it got quite hot. Didn't try the A/C tho, that may have other problems since that was not cooling completely right before the gasket blew. I will be able to try this tomorrow and I will let you know what happens. Thanks for all the help.

T.

Finally got a chance to work on the car. You were right. Right on the bottom of the thermostat housing, nestled up against the head was a wiring harness that both me buddy and I missed. It wasn't connected, imagine that. It looked like it was connected into the block the way it was nestled into the corner, which is how we missed it. Anyway, got that connected and the temp gauge moved just fine. The cooling fan never kicked in tho, unless I turned on the A/C. But then the temp never got that hot either and it was a cool night here.

Again, thanks VERY much for the help.

T.

Ok. Everthing works fine now, except the cooling fan. It never kicks on by itself, but it does turn on low when the A/C is on. I tried a code reader to see what was wrong and it didn't report anything wrong. The fan even came on for that. :banghead:

Any ideas will be appreciated.

Thanks,
T.

Hi Zombie.

How are you testing cooling fan and how hot are you letting engine get? :confused:
The best way is to run car till engine is at normal running temp, then let engine idle while stationary and watch temp gauge, fan should cut in when needle is about at the 'a' in normal. My wife runs a 1996 Contour and fan does run at the 'a' in normal.
As yet I've not located the fan temp sensor but a friend says it should be in radiator bottom right corner, look for wiring conector, remove and bridge the 2 wires together, if fan runs then maybe sensor has failed.
Best of luck
Englishman. :wave:

Hi Zombie.

How are you testing cooling fan and how hot are you letting engine get? :confused:
The best way is to run car till engine is at normal running temp, then let engine idle while stationary and watch temp gauge, fan should cut in when needle is about at the 'a' in normal. My wife runs a 1996 Contour and fan does run at the 'a' in normal.
As yet I've not located the fan temp sensor but a friend says it should be in radiator bottom right corner, look for wiring conector, remove and bridge the 2 wires together, if fan runs then maybe sensor has failed.
Best of luck
Englishman. :wave:


I've done that. Also driven it to work, which is about 20 miles of stop and go at rush hour, and to my knowledge the fan never kicked in. The temp gauge sits right about the start of the A, but when I was driving, it crept to the L before I turned on the A/C to kick it on and cool it down. If I leave it sit idling, it heats up to the middle if the A and then cools down a little to the end on the M or begining of the A. Seems that it should be hot enough to kick on the fan, especially since, according the Haynes anyway, the fan should be on like 100 deg cooler than the thermostat will fully open at.

Anyway, I will check the wiring harnesses again and see what I can see. Thanks for all the help again.

T

I am curious to see if you ever found a solution to your fan problem. I recently went through the same problem. The fan would run in low gear with the a/c on, but would not otherwise kick in. The solution was actually quite simple - I replaced the high speed engine fan relay (black), and the problem was solved. Unfortunately for me, even with the fan working properly, my engine still runs hot. I have replaced the thermostat, but the engine temp gauge still goes all the way up when the car has been running for a while. Any suggestions?