I believe I need an IRCM

cougarxr7

Registered User
I turn on my ac, rad fan does not come on.
Put temp switch to ground, gauge shows full diflection, fan does not come on.
Put 12v to fan, and it runs.
I believe I need an IRCM, one for a 1989 xr7,
"E9SF-12B577-AB"
 
With the engine running, does the fan come on if you remove the connector to the ECT (over by the A/C compressor)?

Note the wire for the gauge is just for the gauge.
 
KMT, I did not run that test but if I am not mistaken when you turn on the defroster the rad fan should run.

UPDATE:
Just tested IRCM for power, and all power feeds to the IRCM are hot!
UPDATE:
Fan ran with ECT disconnected!
Fan does not run when AC or defroster is turned on.
 
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KMT, I did not run that test but if I am not mistaken when you turn on the defroster the rad fan should run.

UPDATE:
Just tested IRCM for power, and all power feeds to the IRCM are hot!
UPDATE:
Fan ran with ECT disconnected!
Fan does not run when AC or defroster is turned on.

If the fan runs with the ECT disconnected, then the fan relay is fine. At least one of them is ... I forget if it's high or low speed that kicks on in that case.

Did you test both speeds of the fan to make sure they both work? There are two sets of brushes in there.
 
At this point, I'm not sure the IRCM is your issue with the fan not coming on with A/C.

Have you checked the A/C system for pressure? Checked the 15A A/C fuse under the dash? Is the A/C clutch in good shape? Note too that it might take a few moments for the fan to be triggered when the A/C system is operating correctly.

And as S-Mazza asked, be sure to check both Hi/Lo fan circuits - unplug the connector, probe to learn which pins is ground, then jumper a hot 12v to each of the other two in turn to confirm fan windings are ok.
 
Thanks for the help!!!!
At this time here what I have.
Ran the car and fan came on when temp got high!!
My problem now is fan does not come on when ac or defrost is turned on.
I have electrical schematic and can read it.
Not sure what speed is used when but I will test to make sure both speeds work.
Agan, thanks for the help!!!
 
If it runs on both speeds when applied directly, then both parts of the fan actually work.

If it runs when the ECT is unplugged, then at least one of the fan relays in the IRCM is fine.

Try this: Unplug the black barrel connector on the ground wire attached to the negative battery cable. (Running down in front of the battery.) Then turn the key on. Does the fan run?
 
I did what you said and the fan ran when key was turned on!

Well, good news and bad news.

The good news: Your fan seems to be fine!
More good news: Your IRCM seems to be fine!

The bad news: The problem is somewhere else. :eek:

Sounds like your A/C system may be low on refrigerant, as KMT said in his last post.

I think you can jump the wires at the connector for the low pressure switch to simulate a proper pressure condition. The switch is at the accumulator / dryer. Try installing a jumper wire there, then turn on the A/C, and see if the fan runs.
 
"if the A/C system is low on refrigerant", that would prevent the fan from running???
The ac worked last year, so this is something new.
 
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"if the A/C system is low on refrigerant", that would prevent the fan from running???

As I understand it, it would not prevent the fan from running based on engine temperature, but it would prevent it from running based on A/C operation.

To back up a little, if the system is too low on refrigerant, there really won't be any A/C operation, because the compressor will not engage or stay engaged, regardless of the driver's selector switch position. With no pressure in the system, there's no need to run the fan to pull air over the condenser.

Have you checked that the compressor clutch is engaging?
 
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