kenfrancis57
New Member
Have you tried shopping switches around to find out if the switch is faulty
Datatek
Well-Known Member
The rear windows are controlled by the BCU (under N/S front seat), and the relays, (if you can hear them), are in this unit...
If the window goes down OK, but not up, it could be the anti-trap function not allowing the window to go up...
These anti-trap switches are a rubber coated contact strip which is installed along the top of the window frame. This can be over-ridden by holding the window close switch in the one-shot closed position until the window goes up...
Being under the seat, the BCU is very prone to water ingress, so this should be checked properly ....
If the window goes down OK, but not up, it could be the anti-trap function not allowing the window to go up...
These anti-trap switches are a rubber coated contact strip which is installed along the top of the window frame. This can be over-ridden by holding the window close switch in the one-shot closed position until the window goes up...
Being under the seat, the BCU is very prone to water ingress, so this should be checked properly ....
Datatek
Well-Known Member
Sorry, on the P38 it's not a BCU, it's the BECM and it's under the drivers seat on RHD. Never known the trap feature to be a problem.The rear windows are controlled by the BCU (under N/S front seat), and the relays, (if you can hear them), are in this unit...
If the window goes down OK, but not up, it could be the anti-trap function not allowing the window to go up...
These anti-trap switches are a rubber coated contact strip which is installed along the top of the window frame. This can be over-ridden by holding the window close switch in the one-shot closed position until the window goes up...
Being under the seat, the BCU is very prone to water ingress, so this should be checked properly ....
I don't even want to go down the becm route datatec but I've done the contact cleaner and hit the switches a few times and they work intermittently that will have to do trying to sort the rear subwoofer now had a amp bloke look at it today for me and says he finks the amp is ok do u no I've they have a digital on of signal as they have got power to the amp constant even with the ignition of
martyuk
Well-Known Member
The subwoofer is permanently powered, yes. There is a remote 'wake up' wire which then turns the amplifier on when the head unit is powered up.
On the P38 the 'remote on' wire is Grey with a Black stripe. The head unit powers this wire with 12V when it turns on and gives the signal to the door amps, FM receiver amps, and the subwoofer to all power up and start doing some work.
If it's just the subwoofer that is playing up, then it could be that the Grey/Black wire has a fault in it in the loom somewhere (it will splice off the loom - possibly in the loadspace near the FM receiver/amp).
If you have a mulitimeter, then you can test the remote wire by putting the negative probe on the black wire and the positive probe on the Grey/Black. On a voltage reading you should get 0V when the radio is off, and 12V when it is on.
If you get power there when it's on, then the issue is either the sub amp, the subwoofer unit itself - or the signal wires (orange and orange/black) not passing the signal to the amplifier to be processed.
In the LH (UK Passenger) footwell, behind the kick panel there are a couple of connectors in there which are known to get damp and corrode. The signal wires (and I think the 'remote on' wire from memory) go through one of these connectors - so this is also worth checking out. If the pins are looking green, then a lot of people (myself included) cut the connectors out and resolder the wires together and heat shrink them so they can't corrode in the future.
Hope this helps,
Marty
martyuk
Well-Known Member
Probably worth pulling the head unit out. Chances are the signal wires (orange + orange/black aren't connected to anything. If your head unit has a pre-amp output (RCA terminal) then you could wire the sub lines to a connector and plug it in - most head units have a selectable sub/rear for the pre outs. If you don't have a pre-out then depending on how the stereo is wired, you may be able to put the subwoofer signal wires in parallel with one of the rear speaker lines (assuming they have used pre-amp outputs for the door speakers - and not bypassed the amps in the doors and wired the door speakers direct to the head unit amplifier.
Would really need a bit of hunting around to see how they've wired in the head unit to see what your options are...
Would really need a bit of hunting around to see how they've wired in the head unit to see what your options are...
