Thread: hvac system

Hi Mate

Sadly i think you may have blend motor problems

More info here

Blend Motor Diagnosis and Replacement

Good luck
Steve

In the bonnet fuse box rl 6 and 7 are the two relays that supply power to the two fans. You could jumper both of these and see how it goes. These are feed by two 25a (I think) fuses.

Is the temperature left and right the same?
When you turn the fans right up is there any air coming out at all?

The blend motors change the temperature and which vents the air comes from.
The temp can differ side to side but if all is well the selection of vents should be the same both sides. There are however two independent fans, one for each side. Is the passenger side fan running at all? If not there lies the problem. The part of the fusebox that burns holds the relay for the fan.

The fans take 12v from the relay and the speed is controlled by regulating the resistance to earth via the hevac unit. Start checking the + to the fan. Its easy to get at.

been reading up, looks like I might be in the market for a new fuse box as well as the blend motor, or maybe the fan.

I will go through the options for trouble shooting tomorrow and will post my findings so hopefully I will at least know which way to go.

thanks for all your help already

I doubt very much its the fan,
Drop the panel / glove box and you will see the fan. There are two plugs going to the fan. The multi plug goes to the hevac, The single plug is the Poss+ feed.
Check you have 12v power here. If you do undo the 3 screws holding the fan in place, remove the plugs, remove fan assy and put it on the bench and test it. If the fan spins up look at the fuse box.
Beware the fan has a serious kick to it when you connect 12v across it. Hold it down firmly

This afternoon I got a chance to test things.

Turned the car on, usual check book and exclamation mark and drivers side only getting air conditioning, started trying all the settings as per fault finding guide and low and behold there is air blowing low, then high and then it looks like I made up the whole thing, could something have just got stuck and needed to be moved?

Visual check of the fuse box and the usual offending relays showed everything looking very clean, unburnt and fine, is there any easy way to clear the fault symbols and see if they come back?

Think this is my proper welcome to P38 ownership!

Originally Posted by finallyrangie

This afternoon I got a chance to test things.

Turned the car on, usual check book and exclamation mark and drivers side only getting air conditioning, started trying all the settings as per fault finding guide and low and behold there is air blowing low, then high and then it looks like I made up the whole thing, could something have just got stuck and needed to be moved?

Visual check of the fuse box and the usual offending relays showed everything looking very clean, unburnt and fine, is there any easy way to clear the fault symbols and see if they come back?

Think this is my proper welcome to P38 ownership!

For me, I carry the Blackbox FCR in the glovebox. It won't fix any problems or let you change any values but it will identify the faults and also clear them.

https://blackbox-solutions.com/shop/

Good luck

Gary

HI

As far as i know there is no way to clear the book symbol except by fixing whatever it thinks is wrong.

Have you tried swapping the relays around or replacing them?

Steve