Mechanics

OVERHEATING

2003 Ford Focus • 65,000 miles

I just replaced a new expansion tank the other one had a crack on the bottom. Yesterday I took off the water was full. And it was really a hot day also.I went a few places and the temp gauge was normal, everything was fine.I stopped by a friends house and as soon as I left there that gauge went up so fast I couldn't believe it I only got a couple of blocks and I shut it down. It was so hot I could hear boiling.I let it set for a long time put water in because it blew it out being so hot drove home and it was allright. Today I checked the fuses they seemed good.I checked the fan resistor on the bottom of fan shroud. It didn't have any burnt terminals and I checked the resistor for continuity and it had a reading.I looked at the oil for signs of moisture and the oil cap looked good.I even let it idle for a good 20 to 25 minutes today and it was fine. Maybe the cylinderhead temp sensor how do you check them, could that maybe be keeping the low speed fan from coming on it has twin fans?
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Randy sharp
June 3, 2013.




So doen 't one of your fans work? High speed only comes on with a/c. Check relays and also have coolant system pressure checked for head gasket etc. Also check the resistor in pic


Hmac300
Jun 3, 2013.
When I test the relay it has about six or so terminals. Yesterday I tested it with mutimeter, I set it on the lowest setting 200 and the only reading I got was 1 is that right. And the picture you sent me is the fan resistor correct.I did test it. It did have a reading on the resistor I unplugged it and it had no burnt out terminals. And both fans work when you turn on ac. And there is a low speed correct could it be the cylinderhead temp sensor not turning the low speed on?And thanks for all the help I appreciate it


Tiny
Randy sharp
Jun 3, 2013.
Heres a chart to test the sensor the left column is temp in f and c and the far right is ohms what it should be.


Hmac300
Jun 3, 2013.
Also test to see if anything goes to the relay, but if both fans are working then it's not the one relay there are 3 for this.


Hmac300
Jun 3, 2013.
Where are the rest of the relays I only know one?
AD


Tiny
Randy sharp
Jun 5, 2013.
If this is a svt there are 2 if it's not there are 4 if it's a 2.3L there are 3 you test them by replacing with a like relay they are all located in battery junction box. One is called a power hold relay that could be bad as well


Hmac300
Jun 6, 2013.
If I want to test the cooling fan relay. There are six terminals, how do I tell which ones are the control terminals and which ones are the power terminals?


Tiny
Randy sharp
Jun 6, 2013.
Just replace it with a like relay that works is the easiest way all of them have 5posts that work not 6 besides you never told me what system or engine you have or whether it is an svt. Read previous replies.


Hmac300
Jun 7, 2013.
Hello to hmac300. My focus has a 2.3 litre motor dohc thanks for all the help


Tiny
Randy sharp
Jun 11, 2013.

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