I have a 1993 240 and after I turned the car off the fan in the front of the radiator stayed on until it sucked all the power out of the battery and I had to get a jump. The mechanic took the fuse out, said it could be a faulty relay and it comes on when I have air conditioner in the summer. Can anyone tell me what they think it could be? I was 4 hours away from home when this happened over the holiday. If it's a troublesome relay where is it located and can I put inin myself?? thanks for any info...Lynn

The others got bits and pieces right, but here's the way it works on a '93 240 (and it's different from the other models):

The electric, auxiliary fan is driven by a fan relay (apart from the A/C relay). The relay, in turn, is controlled by a pressure sensor -- the fan isn't supposed to always work when the A/C is on (as has been reported by another), but only when the A/C is working hard (in hot temperatures) and therefore building enough pressure to close the sensor's contacts. And it shouldn't work when the car is shut off.

The fan relay is (on the '93s) located all alone (no other relays to confuse with it) on the driver's side (left) fender just behind the battery, on the metal bar in front of the little black, flat junction box.

By the way, the pressure sensor (the one that controls the fan relay) is located on the passenger (right) side, low down beside the "frame rail" (the car doesn't really have a frame, but it looks like it does). If you look under the lower radiator hose, you'll see a metal A/C lines (don't confuse it with the transmission fluid lines). And on that line, you'll see that there's a branch coming off it (like a railroad's side track diverting from the main track, if you'll forgive this analogy). The branch extends forward, and you can see that it ends at a plug into which a sensor is mounted -- that's the pressure sensor.

Ken,

Excellent information! Didn't realize that the 92 and 93 had such differences! On our 92, if the compressor is engaged on ours (no matter how hot or cold), the aux fan kicks in.

Based on your statement that the AC fan relay/fan is fed through the ignition switch, are you saying that this might be a double fault, ie. bad ignition switch and bad relay or pressure switch?


jorrell
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92 245 245K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently in pieces

re: "...Based on your statement that the AC fan relay/fan is fed through the ignition switch,..."

As I wrote a moment ago, I didn't say that exactly. But I went back to my post and found where we got confused, which is where I wrote, "...And it shouldn't work when the car is shut off...." You thought I implied the ignition switch (which is understandable), whereas I meant the F.I. control module (which should also be off when the car is shut off). A little misunderstanding, easily explained. :-)

Have a great holiday season.

re: "...Didn't realize that the 92 and 93 had such differences! On our 92, if the compressor is engaged on ours (no matter how hot or cold), the aux fan kicks in...."

I also didn't know that the fan doesn't always work -- when I got my first '93, I worried (when it came the summer) and the fan didn't come on (that was before I was able to score the '93 Green book on eBay). But soon, on a hot day, it came on, and I realized it was pressure dependent. And when I finally got my Green book, I could see in the diagram (on pg 112, with references to items by letter for anyone else with the book who is also reading this) that there is the pressure sensor (F) as the direct, sole controller of the fan relay (D).

re: "...AC fan relay/fan is fed through the ignition switch...."

I don't remember writing that about the ignition switch. They aren't, at least not directly.

The fan relay's load current comes directly from the battery, via the later '93s' unique array of 4 fuses (H) on the battery's positive terminal, so it's always "hot". But the relay's coil current actually comes from the FI Control Module (214), via the other pressure sensor (J) in the dryer when its contacts close (btw, this 'close' also powers the heater fan to run, even if it isn't turned on with the switch).

All in all, I agree that the fan relay is the best suspect, since it's "live" all the time -- if its contacts stick closed, the fan will run regardless of anything else except pulling its fuse.

By the way, the fan is run off a different fuse (on the positive battery terminal) than the rest of the A/C system. The fan is run by the Blue 20A fuse, whereas the rest of the A/C system is run off the Yellow 60A fuse (see pg 2).

Happy holidays.

Ken:

Awesome answer! In short, I need to go out and get myself a 92 green book! Excellent detailed explanation of the AC fan circuit... Thumbs up! Think I might need to re-check the charge pressure just to make sure its not over spec (could explain why the fan kicks on every time the compressor kicks on).

jorrell
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92 245 245K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently in pieces

Hi.
Did you ever get the wiring diagram I sent you (a scan, for '93)? I sent it to your brickboard e-mail address, j______ (at) qualcomm.com. Is this still correct (I modified it here so a spammer can't obtain it, but you know what I'm referring to).
If you had any difficulty opening the attachment, let me know. It's a jpeg file about 333KB.
Happy New Year.
Ken

I don't know if the '92 is like that -- thers I've owned jumped from '84 to '93, so I don't know anything about the in-between years. There's always the possibility that what I described is unique to '93 because it's the first year that they switched to the R134a (although I don't know if this has anything to do with what we've been discussing). Anyway, I'm going to try to e-mail you a scan of the page when I can get to a scanner.

Happy holidays.

Ken:

Got the email and thank you! I just assumed that little pressure switch was a safety shutdown. Now that I have reviewed the schematic you sent, its obvious that you were right and my assumption was a POS! I'll be ordering a 92 green book tomorrow!

Once again, thanks for the info and correcting my post!

jorrell
--
92 245 245K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently in pieces

I haven't ever had this failure on a 240, and so haven't looked at a 240 wiring diagram but normally these fans are permanently live. I'd have a measure of the fan switch in the rad as these are known to fail

Peter

Peter:

The 940 has an electric fan only. The late 240s have a mech fan and an aux electrical fan in front of the radiator. On the 240s, the aux fan is only tied into the A/C system and does not use a thermostatic switch in the radiator. The aux fan only comes on if the AC compressor is running.

jorrell
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92 245 245K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently in pieces

The relay is actually clamped to the ignition coil. Every once in a while my fan will reamin on after shutdown, as well, and the 'cure' is to simply give the realy a smart rap with a screwdriver handle. If it's happening all the time, then replace the relay.
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Thank goodness we don't get all the government we pay for. -- Wiley Post

Lynn:

First off, Merry Christmas. Yes, there is a relay for the fan, it is #114 in the
Bentley manual, unfortunately, the manual does not show the relay location, and there are typos / omissions in the schematic, so I can't trace it back to the proper fuse or main power tap.

Due to the schematic issues, I can't tell if that fuse is always powered, or if it is switched through the ignition switch. If it is "switched" through the ignition, then it might be an ignition switch problem, or a fan relay problem.

Hopefully, someone out there has a set of 93 Volvo Green book schematics to track it down for you, all I have is for a 90 which doesn't include an aux fan.

The relay should be pretty easy to swap once it is located, ignition switch can be done in a couple of hours with a Torx screwdriver set and a little patience. If you have a lot of keys on your key ring, suspect the ignition switch even more... this wears out the switch pack. I'm sure someone out there will step up with the relay location and main power source for that fan.

jorrell
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92 245 245K miles, IPD'd to the hilt, 06 XC70, 00 Eclipse custom Turbo setup...currently in pieces