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Fan and temp switch

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7.8K views 4 replies 4 participants last post by  4lights  
#1 ·
Last weekend I got stuck in traffic for the first time in a while with my 94. The temp gauge started going up and up so I had to pull over.
When the car cooled down I got it off the highway and went to the shop to check it out and both fans were dead.
I stole the fan from my turbo regal for the time being and started searching the forums for info. What I figured out is the fan motors on these things are junk. Yesterday I bought an aftermarket fan and installed it. It seems to work fine but what I did notice was that once it got up to temp to turn the fan on, it wont shut off. Did this with the original and the TR fan too.

Now the engine on this car has had some modifications from the original owner and the second owner who I bought the car from just drove it and really didn't know much about cars and taking it to a mechanic for any work.

What I am wondering is maybe the original owner swapped in a colder stat at one time and got one of those temp sensors that will kick the fans on early.
I do know that the guy I got the car from had a new water pump and rad put in. I think maybe they put a new stat in it too and more than likely it is a stock replacement.

So now I am trying to decide if I should replace the temp sensor, or put in a colder stat to see what happens.

What is the temp stat that these things like?
What is the stock temp stat?
 
C
#2 ·
Stock thermostat is 180F. The PCM controls the fans. Primary fan turn-on is 225F, secondary 232F. If you have any leak in the system that will keep it from building pressure, it will boil over before the fans turn on.

Your fan motors were junk because they're 16 years old. These cooling systems are actually pretty robust, but age and wear take a toll.

You can get your PCM reflashed to lower the fan turn on temps.
 
4
#3 ·
Same problem, except I'm not 100% sure it's a bad fan motor yet:

1) Driver's side fan is not on when A/C is on. Am I correct in remembering that the A/C being on is reason enough for both fans to be on? (I'm unsure whether the temperature alone at the time I found this was high enough to have on the D/S fan.)


2) Any reason to suspect its anything but the fan motor? I seem to remember it's a two-pin plug, so I can measure for voltage at the plug with the key turned on and the engine off (if 1 above is correct...)

3) I was on the road when I discovered the fan and couldn't look at the actual parts closer, but found in the owner's manual diagram of the underhood fuse box a) a fuse b) another fuse c) a relay, one of each per fan. Is that right? Are those two fuses each for the switch part ad the coil part of the relay, or is there another reason for them, or is the diagram mistaken?

thanks.
 
F
#4 ·
4lights said:
Same problem, except I'm not 100% sure it's a bad fan motor yet:

1) Driver's side fan is not on when A/C is on. Am I correct in remembering that the A/C being on is reason enough for both fans to be on? (I'm unsure whether the temperature alone at the time I found this was high enough to have on the D/S fan.)

2) Any reason to suspect its anything but the fan motor? I seem to remember it's a two-pin plug, so I can measure for voltage at the plug with the key turned on and the engine off (if 1 above is correct...)

3) I was on the road when I discovered the fan and couldn't look at the actual parts closer, but found in the owner's manual diagram of the underhood fuse box a) a fuse b) another fuse c) a relay, one of each per fan. Is that right? Are those two fuses each for the switch part ad the coil part of the relay, or is there another reason for them, or is the diagram mistaken?



thanks.
Click to expand...
1) No, the A/C will cause the primary(passenger side)fan to come on.
2) Yes, the first thing to check is the relays. Pull the pigtail off at the sensor and both fans should come on within a few seconds. If one comes on and the other does not, try switching the relays to isolate a possible bad relay.
3) Just do the above tests for the relays and check the contacts on the relays. If the relays are OK, then likely the fan motor is bad and it is the next thing to check.
 
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