406 phase 1 heater fan

[moizeau]

The car has auto a/c, so just buttons on the fascia. The heater fan goes flat out when the ignition is on and can't be lowered. Having done a quick read up I believe the problem is down the the fan resistor unit, or rather a transistor within the unit. On phase 2 models it is separate but apparently on phase 1's it's built into the fan assy and can't be repaired. I've unplugged the fan to protect the ignition barrel connections (replaced only a couple of months ago due to a melted wiring block). Could someone confirm or otherwise the above please. Also as there are only LHD cars in our tat yard, is the fan assy the same and mounted in the same place?
Going to bodge a toggle switch in to the loom temporarily to help demisting in the morning until I can get one at the weekend
Thanks very much in advance

[Oldpug]

I`ve only ever removed a RHD motor and it was easy,located under the glove box,a few screws and it drops down into the foot well. I have a feeling that LHD 406`s its the same,but on the other side?
I`ve just checked with Peugeot Service Box. LHD and RHD motor assemblies are different so this backs up my thoughts. The motor resistor IS sold separately,part number 6441.78,but its very difficult to replace it.
You will find it a lot easier just to swap the whole fan unit with a used one.

[xantia_v6]

It is not clear whether your car is LHD or RHD.

If you have a reasonable tool kit, you should be able to replace just the transistors in the speed controller, I imagine that it is the same as the Xantia one, and there are several descriptions of that job on this site if you search.

[moizeau]

Thanks very much both of you for your replies. Mine is RHD, so getting a 2nd hand one will be nigh on impossible unless I order it from the UK and pay the shipping. I imagine that would sting a bit. I'll have a search later for the repair when I get back from work.
Regarding a good tool kit, what would be a special tool here apart from de-soldering and soldering tools, which I have?
Would the resistor be the same for LH and RHD? If so I could still go the LHD blower and use it for parts, I'm guessing the mountings and outer casing are different but internal components are the same otherwise it would get expensive for Mr Peugeot to produce.

[Oldpug]

The resistor unit is the same on RHD & LHD, so either buy a new one (part number 6441.78) or get a used LHD motor and pull it apart. I`m trying to remember? its a tricky fiddley job and I think you have to remove the fan blades.

[Paul-R]

If you do go down the S/H route you'd have to be sure that the resistor came out of a non-dual zone A/C unit. I'd be willing to bet that many breakers would not be aware of the difference.

[moizeau]

Thanks for the info. I've read up on the Xantia threads. Apparently the only difference is that they spin the other way. If they are fundamentally the same the motor with fan blades is removed as a unit ( 3 screws) exposing the transistors mounted on the heatsink. Is there any way to confirm the transistors are open circuit without removing the blower using the various plugs and sockets?
Something to play with on Saturday.
Thanks again

[moizeau]

Right, the transistors should arrive today. I want to do the relay mod whilst I'm in there. Been checking all the posts but they are related to the Xantia and the wiring is slightly different. Could someone confirm what I'm about to do is correct please? In the Haynes BOLs is says wire KK! comes out the ignition then splits in to two, one going to the passenger fusebox (fuse 21) the other going to connector 4 om the module . This would be the correct wire to cut and use for the relay signal, using connector 2 wire as the relay earth? Then splice into the red wire that feeds the ignition from fuse 2 (battery fuse box 1) and send that through the relay and join it the the wire going to connector 4 (the other half of the wire previously cut) By using the above method of cutting and splicing, the new heavy duty motor feed is using the original fuse that protected the circuit (fuse 2), so I wouldn't need to add an inline fuse?
Would this be the right way of going about it?
Confirmation or criticism and corrections greatly received.
Thanks .
https://www.frenchcarforum.co.uk/forum/ ... ew&id=5270

edited due to putting wrong wire colours in original post

[moizeau]

Updated with a scan of the BOL's to assist any gurus that didn't ave access to the 406 book.
Thanks

[moizeau]

Just to say the heater is now working normally, got the parts off ebay using the part no. Jim gave in the xantia thread. 8 quid shipped to France for 2. Only one transistor was knackered but I changed both as a pair Once the blower is removed it took about 30 mins to dismantled, desolder, clean than rebuild. About 5 minutes to refit the blower once you know how it fits.
Not had chance to do the relay mod, so I've left the cowling off for the moment. Can anyone confirm my wiring idea above please? The colour coding is different to the Xantia thread and a lot of the links don't work due to them being posted 10 or so years ago.
Thanks