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1999 VOLV S 80 Turbo 2.8 L

Hello all, my 1999 Volvo has been diagnosed by a Volvo dealer to have a bad “coolong fan relay”. Another shop analysis states the “cooling motor fan assembly module” is the problem. Are these one in the same? Can I replace it with one from the salvage yard? Are there any bad omens with messing up other electronic componets If I make the repair myself?

I’d see if you can get the parts. I was able to find Volvo parts on the web and ebay. I’d replace the relay first. If that didn’t resolve it then I think the cooling fan assembly module is pretty much the cooling fan motor. If you can get to the parts it should be easy disconnect on electrical connections and remove and replace.

If you want to be super careful you could disconnect the battery to be sure you don’t short anything out, but that seems like overkill. I won’t bother if all the electrical connections on the new parts match the old ones.

You could check whether the relay or fan is bad by taking the relay out and carefully shorting the yellow/red to the red wire. The fan should turn on at some predetermined speed.
Shorting the yellow/red to green should turn on the other fan speed.
Make sure you don’t short against the other yellow/white or white/yellow wires as those go directly to the computer.

No doubt you’ve checked the fuses but you may want to check that ground connection at the fan (black). If that’s not there, that fan will never work.

If you know how to read a schematic and use a multimeter, maybe spend some time with it first, before you replace parts.

Forget what I said above:
An S80 is a bit different than the above schematic (S70).

If I were you, get a multimeter, run the car and briefly turn the AC on. “Briefly” because having a car running without a fan is bad. Running a car with the AC on is even worse. Only run it a minute so it may require two people: one to measure and one to start the car.

You should see 12V across the black and white connections of the fan.
If you do and the fan does not turn on, the fan is likely bad.
If you don’t see 12V, it could be that ‘engine cooling fan module’. In that case, the fan is likely fine. That module could be a simple relay but I suspect it has some sort of smarts in it since it only requires one line from the engine control module and yet your fan likely has multiple speeds… That violet wire may very well be a communications line of sorts, something you may not be able to check with a multimeter.
That module may be at fault.

The fan works. It will not shut off unless you pull the harness apart.

Ah, so it never shuts off, even when you turn off the ignition? You didn’t say what the actual problem was so I assumed the fan wasn’t running.
If the fan never shuts off, it must internally be shorted so it likely is that module.

Yeah, sorry about that. It troubles me that the Volvo dealer said it was the fan relay. I saw the ticket…with a repair quote of $500.00 plus. Most of the cost was for the relay. Last relay I bought (AC relay 1997 pick up) was $15.00. She called Dobb’s and over the phone they told her it was the fan cooling motor module. The owner’s manual identifies the fuses, but not the relays. In order to find the fan cooling relay may be I should start pulling relays. Will I damage any electronics if I start pulling them until the fan stops; and then substitute one of the other relays to see if the fan works and shuts off when temp. is satisfied ? If so I could proove the relay is bad, and possibly find a good used one.

And yes the fan continues to run with the engine off, do not know about ignition.

Fan does run with ignition “OFF”.

I found this site that may be of use to you.
There’s a drawing that identifies where that module is located:

With smart systems like that, it is difficult to tell what’s going on as a system.
If I had to draw from the hip and replace one part to fix your problem, I’d replace that fan module. It is controlled by the ECM and it must somehow issue commands to this module. Of course, it could al could also be that the ECM is hosed but let’s hope that is not the problem.
It looks like it is located in front of the radiator and it just unplugs and unscrews.

Here’s some recall info:

Sounds like another overcomplication of a solution that wasn’t a problem to begin with.