Cooling problem

johnwartjr

Registered User
Now that it's good and hot in Indiana, I'm having a cooling problem with my SC

On a day that is 90 degrees, I can drive across town (10-15 minutes tops), shut er down, and when I fire it back up, the gauge is buried in the red and the check gauge light comes on.

Turn off the A/C, it drops to the left a little and the check gauge light goes out, but it's still on the hot side

The fan in front of the condenser is working.
The fan behind the radiator has not turned on yet, but I've been unable to determine when it should start.

The radiator is dropping the temp of the coolant 25-30 degrees from the top to the bottom.

Is there a relay I should be tripping to see if the fan will turn on?

Or when should the car run the fan?
 
Thought I'd add that the coolant level is fine, is not dropping, and the water pump makes no noises and does not leak.

Radiator was serviced in the last 12 months, meaning it was pulled and the top tank was removed and resoldered to fix a crack.
 
Just found that Mega Fuse 5, 60A for the Engine Fan is blown.

Guessing either a bad relay or fan, does that sound logical?
 
Does anyone know where the relay for the engine fan is located, and how I test it?

Is it one of the relays in the box with the mega fuses? Or is it mounted elsewhere?

How hard or easy should it be to spin the engine fan? I unplugged it and tried to spin it by hand. It wasn't stuck, but it didn't turn very easily either.
 
What year is your car? I just answered someone else with a long write up regarding the 94/95 years about three days ago.
 
I read through this post of yours

http://www.sccoa.com/forums/showthread.php?p=747842#post747842

But it does not indicate where the relay is for the fan - I've found a few under the hood. 4 in the mega fuse box, one located near the front fan, but have not figured out where the fan relay is.

I do not wish to modify my system, the original relay and fan have functioned fine for 13+ years and 125+k miles, just wish to repair the OEM system.

When you say hotwire the windings that don't work - neither winding of the engine fan turns since the fuse is blown. Are you suggesting I replace the mega fuse, then jump 12 volts to each winding of the fan and see if they run?

Or should I just pull the fan out and hook it up to an external 12v source and see what happens?
 
How would you troubleshoot this if it were your car?

A) Replace mega fuse, run KOEO test and see what happens?

B) Remove the fan and connect +12 to each winding and verify it turns?

C) Remove the relay, bench test it and see if it relay works properly?

or D) ?

Just trying to figure out what I need to get and how I need to test things.

BTW, found the relay box, looks like I need to remove the 3 fasteners that hold the air filter box in to get the cover off, not a big deal.
 
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Or should I just pull the fan out and hook it up to an external 12v source and see what happens?

This is how you test the fan motors to see if the low and high speed windings work.

The IRCM is behind the PS headlamp and contains 4 relays, two of which are for the main fan.

If the fuse is melted (typical), splice in a new fuse holder to the fan's yellow power wire and run power off the + terminal on the side of the power dist. box.
 
When you say hotwire the windings that don't work - neither winding of the engine fan turns since the fuse is blown. Are you suggesting I replace the mega fuse, then jump 12 volts to each winding of the fan and see if they run?

Or should I just pull the fan out and hook it up to an external 12v source and see what happens?

Replace the blown fuse and see if the fan will come on. If the fuse blows again, did you check to see if the fan will move freely with no power? If the fan will move freely with no power, but blows fuses, most likely the fan is drawing excess current when it runs that melted a wire somewhere or finally blew the fan fuse.

Replacement fan motors are available in the aftermarket at auto parts stores.

The relays that operate the fan are built into a Module and are not user serviceable.
 
Replace the blown fuse and see if the fan will come on. If the fuse blows again, did you check to see if the fan will move freely with no power? If the fan will move freely with no power, but blows fuses, most likely the fan is drawing excess current when it runs that melted a wire somewhere or finally blew the fan fuse.

Replacement fan motors are available in the aftermarket at auto parts stores.

The relays that operate the fan are built into a Module and are not user serviceable.

The fan turns, but it doesn't spin very smoothly. It feels like it has a little bit of drag to it.

I'm not sure if that's normal or not.
 
How would you troubleshoot this if it were your car?

A) Replace mega fuse, run KOEO test and see what happens?

B) Remove the fan and connect +12 to each winding and verify it turns?

C) Remove the relay, bench test it and see if it relay works properly?

or D) ?

Just trying to figure out what I need to get and how I need to test things.

BTW, found the relay box, looks like I need to remove the 3 fasteners that hold the air filter box in to get the cover off, not a big deal.

A, then B. If the main fan doesn't cycle low then high, test the windings by jumpering them. If they both tst fine, you likely have a bad IRCM.
 
OK folks, thanks for the help, I just had a breakthrough that may have simplified the repair for me.

Went out to pull the mega fuse to see if the wiring had melted near the fuse, and thought I'd spin the fan again for good measure.

Started spinning it, and hit a spot where it just locks up. Guess I'll be hunting a motor tonight.

Advance Auto has a motor for 60 bucks, AutoZone is 90.

Advance has been more helpful with previous problems, and they are less, so I will start there.

The blades slip over a roll pin or spline in the shaft, and an e-clip or something holds the blade on the end, correct?
 
The blades slip over a roll pin or spline in the shaft, and an e-clip or something holds the blade on the end, correct?

Yeah, there is some sort of clip on the end of the shaft holding the fan to the motor. It'll be obvious when you take it out.

To get the shroud out without removing the upper radiator hose can be tricky. If you have enough clearance (automatic coolant lines can make this tougher) you can often rotate the shroud by dropping a corner down an then lift it out rather than trying to lift it straight up.
 
Thanks for the heads up. I can't dig into it for another couple hours, will try to get it out without pulling the hose as I don't want to have to bleed the cooling system :)

If I get it loose, maybe I could change it with the shroud unbolted but still in the car :)
 
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