Cooling fan issues!

[Fuzzdog]

One more question! Just one fault remaining on the newly acquired 406, which is... The cooling fan!

It doesn't appear to do much, and there's a 'Fan speed does not match the requested speed' permanent fault logged, with a couple of other fan-related codes. I had a good search for a troubleshooting guide, but of course, being a lateish D9 110, it doesn't appear to be as simple as checking the relays and resistors on the fan, because...



Nope, they're not there. Any ideas where the associated gubbins is located?

[Fuzzdog]

While I'm thinking about it, could the grey 3652 relay be the source of these issues? I may have just answered my own question, as that relay seems to be not particularly healthy.

[GingerMagic]

Hi mate, yes the relay by the battery box is the one for the fan. There is also a plug on the left of the radiator about half way up, where the feed is plugged in.

A fellow member has tried to get a new motor for his but they do seem to corrode and fail over time, it is an easy job to remove fan with surround, to test it, as you can get to the screws through the bottom bumper grill.

I think if you put the aircon on, the fans should start so could be a good way to check??

[Fuzzdog]

Yup, I think that relay may be the problem...





It had fallen off the clip and had obviously got rather wet at some point. Now it's more like an Oxo cube with contacts.

[grasmere59]

I think the fan motors are a problem with later D9's,they have a PCB within the motor which corrodes badly and also the bearings seize up,the rear bearing is sealed but I've managed to keep it going just by drilling a 2mm hole in the rear of the motor and putting a few drops of oil in it but it's on borrowed time.GingerMagic kindly let me have one but that wouldn't run and I dissected it and found the pcb corroded and the brush holders disintegrated,my neighbour has a 52 plate and his fan is u/s aswell.When you replace the relay the easy way to tell if it's working is as Ginger Magic says is to put the A/C on full and the fan should spin.

[Doggy]

A much more certain test is via the actuators test function in PP2000.

Unlike earlier semi-mux cars, the fan won't automatically operate if the A/C's on - it only runs if condenser pressure demands it.

[rwb]

Ah, mux fan
Why the hell a fan needs electronics... :/

[Doggy]

Why the hell a fan needs electronics... :/

Efficient speed control

[Fuzzdog]

Relay arrived this morning, fan fired up with no problems when the air con kicked in. At this rate, my formerly poorly 406 is in danger of becoming a fault free daily drive!

[Fuzzdog]

At this rate, my formerly poorly 406 is in danger of becoming a fault free daily drive!

Famous last words!

I notice that the fan, although now working, comes on whenever the ignition is on and stays on for a few seconds when the car is turned off, even if the engine hasn't been run for hours.

Now it's had both a new relay and a new coolant temp sensor - anything else to check?

While I'm here, what the heck is this little black box clipped down by the engine bay fuse box? Can't find any mention of it anywhere, but it has a hell of a lot of wires disappearing inside.

[GingerMagic]

Hi, not sure what the box is but when I sold my ECU,BSI and transponder, keys locks etc from my donor car - the buyer said this was quite important to go with the ECU as it is coded..?? There are some mighty big fuses in there...

Maybe I was robbed

[Fuzzdog]

It's a box of relays and hefty fuses, all of which test perfectly. Hmm.

Any more fuses or relays tucked away in odd places that I don't know about?

[benczuk]

Apologies for resurrecting a marginally old thread.

After my engine got a little too toasty on a recent towing trip I decided to test the cooling fan using PP2000.

Neither the low speed or high speed actuator tests activate the fans what I do hear however is the fuel pump run?????

Can anyone with a working fan tell me if the fuel pump activates on theirs when they test the fans or is there something very wrong here?

(remapped 2.2 hdi)

[benczuk]

turns out the relay is hosed so guess i will start by swapping that out...

[steve_earwig]

Not sure if that should power up the fuel pump, but if it is well and truly goosed then perhaps it's putting 12 volts into the system.

It's a box of relays and hefty fuses, all of which test perfectly. Hmm.

Any more fuses or relays tucked away in odd places that I don't know about?

I only just saw this, any luck chuck? I posted a few fan schematics on this thread viewtopic.php?f=1&t=18699&hilit=cooling ... g&start=15 if they help.