Radiator fan wont shut off

[kgetchmystique]

Hi all,

Long story short, wife got the car stuck at the ottom of the driveway so I went home to dig it out.

Well I got is out and partically up the drive and started to slip again so I got out to do some more clearing of snow. I left it idleing.

A bit a time later the fans came on...no issue ther it is expected.

Anyway I finally got it up into its spot and shut it down...switch all the way off and key removed.

The fans were still running...I figured it was pretty hot so I went in to change and get something to eat. When I came back out about 30 mins later...fans are STILL running.

I pulled the relay in the fuse box to shut it down.

Any idea what might cause this problem?? I did a couple searches but did not find anything.

Its a 95 Mystique, 2.5L 5-speed.

 

[xtascox]

I would guess a bad relay? I'm not sure how much they run but it could be the culprit. The relay should automatically shut off the fan when power is cut to the motor.

 

[FavoriteMystaque]

Do you need a schematic? It could very well be the relay contacts welded together, I had a brand new one stick in my old Dodge, never stuck again after a tap on the case. Your engine didn't actually overheat, did it?

 

[kgetchmystique]

Do you need a schematic? It could very well be the relay contacts welded together, I had a brand new one stick in my old Dodge, never stuck again after a tap on the case. Your engine didn't actually overheat, did it?

I have a haynes manual but no real schematic.

It did not over heat recently or the incident I described.

This past spring it did overheat when the waterpump went south.

I think it may be the relay cause when I put it back in a few days later, ice cold engine, the fan started right up.

 

[xtascox]

Here you go, they are not too expensive.
http://www.partsamerica.com/Product...&ptset=A&searchfor=Radiator+Fan+Control+Relay

 

[kgetchmystique]

I was just checking one of the schematics in the haynes manual and it appears the high speed fan is only on cars with a/c.

Does this mean the hi-speed only runs if a/c is on?

Can I safely drive the car with just the low speed operational until I get the hi speed diagnosed/fixed?

 

[xtascox]

I was just checking one of the schematics in the haynes manual and it appears the high speed fan is only on cars with a/c.

Does this mean the hi-speed only runs if a/c is on?

Can I safely drive the car with just the low speed operational until I get the hi speed diagnosed/fixed?

No I just believe it is on the same circuit but wired in parallel. I'll double check my manual though. You can run the car without it but be sure to watch the temp. If you haven't had any problems with the car getting hot then you should be fine. Mine on the other hand comes on when I'm sitting in traffic. If you aren't going too far you should be ok. I'll post back in a few minutes after looking at the diagram.

 

[xtascox]

That's just the A/C high pressure cut out switch. I think it shuts the circuit on/off depending on A/C pressure? Anyway, looking at the diagram, the A/C wouldn't have anything to do with the fan running/not running. But it does look like the PCM is on the same circuit and removing the relay would cut power to the PCM. Have you tried to start the car with the relay out? I don't think it would run.

 

[kgetchmystique]

fixed...at least for now.

It was/is the relay. The car will start/run no problem with that relay pulled.

Anyway, when I put the relay back in, fan started to run...engine ice cold. Hadnt run that car is several days. So I pring the relay in the house to check with the DVOM. pin 3 & 5 had continuity when they should be open.

I pryed the cover off the relay to have a peek. Nothing looked odd and when I tried the DVOM again...no more continuity with pin 3&5.

I put the cover back on and put back in the car...this time the fan did not come on. Sooo, the relay must have been stuck closed.

 

[muntus]

I'm going to resurrect this old thread. I need a high speed relay and the local Autozone has the low speed relay. Is the dealership the only place to get the high speed relay these days? Thanks.