Electrical fan.

Is it automatically supposed to turn on when the AC is turned on? Mine is not doing that.

Is there a way to test it and what is the most common problem with the electrical fan that I can test and/or fix.

Thank you.

BTW its a 2000 sport I6

Yeah, it should come on when your A/C is turned on. It is just a simple DC motor, so testing it is easy. Just feed it direct power and see if it comes on, if not, fan is shot get a replacement from source of choice. I recently put a new one in my 92' that I got off eBay for $25 using the factory fan housing to hold it so I used factory mounts.

Just remember, the fan ONLY comes on if the temp reaches a certain temperature, which I believe is around 220. On the 2000 - '01, it'll kick on at that temp if A/C is on or off.

Okay well I drove i around the block pretty hard then came home and parked it. Then I popped the hood and the electric fan finally came on. I guess it works but only comes on when the engine get hot enough.

Well, my aux. fan comes on when the A/C compressor clutch locks or when the engine gets to a certain temp. Actually, when that fan is cycling with the A/C clutch, it's rather annoying, it comes on every 2 minutes or so, for a very short time. Is that normal ?

There are two signals that can turn the fan on - although I think both will come directly from the PCM in your case...

1) A/C Select Enabled. The fan will come on to offset the extra loading of the engine, and to help offset the extra thermal load of the A/C Condenser. This will override the lack of a thermal fan signal.

2) Engine coolant reaches 220*F or so. If the A/C Select is enabled (you've got the Aircon turned on, or the windscreen defogger is on - which also turns on the A/C compressor and the A/C Select signal - your fan will be running anyhow.)

If the fan doesn't come on with either condition in place, suspect the fan relay and start there. If the fan will come on with one signal but not the other, deeper troubleshooting is in order...

If the IP gage also does not work, for instance, you've probably cooked the temperature sensor, and it wants replacing.

If the fan will come on keyed to coolant temperature, it's time to check the A/C Select circuit and find out why it's not talking to the fan circuit.

5-90

cherokee steve said:

Well, my aux. fan comes on when the A/C compressor clutch locks or when the engine gets to a certain temp. Actually, when that fan is cycling with the A/C clutch, it's rather annoying, it comes on every 2 minutes or so, for a very short time. Is that normal ?

Click to expand...

Yes it's normal

Thanks for the reply. Hey, where are you at in MI ? I'm not familiar with South Range.

there was a post like this a while ago. i found it when i thought my 2000's fan was broken b/c it wouldn't come on when the a/c was turned on. i think i eventually found out that the 2000s only come on from the temp sensor.

5-90

just to clarify a bit, on the 2000 and 01 the fan doesn't trigger on the A/C select triggered. There is a head pressure switch that triggers it, so the fan won't come on with the A/C if you are low on coolant or if the switch is faulty.

Take a shot at 5-90's ques.....could it be Buck Godet?

goodburbon said:

5-90

just to clarify a bit, on the 2000 and 01 the fan doesn't trigger on the A/C select triggered. There is a head pressure switch that triggers it, so the fan won't come on with the A/C if you are low on coolant or if the switch is faulty.

Click to expand...

Interesting - I'll have to look into that. I wonder why they bothered to change - seems to me it would less irritating (and less electrical load!) to have the fan running constantly, rather than cycling and having to supply startup load at frequent intervals...

5-90

dizzymac said:

Take a shot at 5-90's ques.....could it be Buck Godet?

Click to expand...

Elabourate, please?

Well all I know is I have a 2000 and the electrical fan works perfect.

When it is at 220 the electiral fan will go on and off as it sees fit.

If the jeep is NOT at 220 and I turn the a/c on the fan DOES NOT come on.

When the Jeep is at 220 and I turn the a/c on the fan DOES come on.

fdsa487 said:

Well all I know is I have a 2000 and the electrical fan works perfect.

When it is at 220 the electiral fan will go on and off as it sees fit.

If the jeep is NOT at 220 and I turn the a/c on the fan DOES NOT come on.

When the Jeep is at 220 and I turn the a/c on the fan DOES come on.

Click to expand...

This is normal operation for that year model. I even brought mine in to the dealership to have them change the computer (under warranty) because I thought this was not the way it should be. I had to pay $50 for them to tell me that there was nothing wrong :looser: . I got the FSM and sure enough, the temp switch has to be active for the head pressure switch to pass the signal to turn on the fan:banghead: .

goodburbon said:

This is normal operation for that year model. I even brought mine in to the dealership to have them change the computer (under warranty) because I thought this was not the way it should be. I had to pay $50 for them to tell me that there was nothing wrong :looser: . I got the FSM and sure enough, the temp switch has to be active for the head pressure switch to pass the signal to turn on the fan:banghead: .

Click to expand...

Cool, now we all know.
Now, give me some of that burbon!!!!!!
:guitar: