Help....P38 Interior lights always on

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Hi,
After a break form most things.

Back to the problem interior lights still on.

Batteries changed replaced charged, switches checked, plugged into faultmate,

Still the interor lights are on.

I looked at the wiring diagram and the bcem controls the ground to the lights looks like one of the power "transistors" in the becm has failed or is pulled to ground.

Or the main wire to the interior lights is shorted to ground.

Strange but the puddle lights work
 
have you try the delay relay that could be bugger , have to look it up in manuel because i got a classic and their in different place to yours
 
bubbleless said:
As Far as I know there is no delay relay its controlled by the bcem.

Which is a very complicated control unit
Click to expand...
No delay relay, it's done by the BECM. Your diagnosis is correct, you just have to find out if it's a component failure or a wire short. I suppose you have tried the push and hold the interior light button for 10 seconds or so?
 
On mine the puddle lamps are specific to the doors but the interior lights will come on when any door is opened. Have you investigated all four doors and their wiring?
 
I'm having this exact issue with the lights staying on. The plugs at the bottom of the A pillar appear dry, but right now can't unplug as car running to charge the battery. It seemed to start with the tailgate micro switch. Gate closed, hit a bump lights on. Every bump would cause an on or off situation. I kept the gate closed but pulled at it to see if the latch was lose. No, but the lights did go off. When I pushed, they came back on. So I pulled the plug to the micro switch and this seemed to tell the bloody lights to stay on, forever! Killed the battery.

I've "instructed" the car to switch all lights off. But all that went off are puddle lights.

The problem then is either a wire or the BECM. Any idea where on the BECM so I can replace the transistor?

Thanks all.
 
Doo said:
I'm having this exact issue with the lights staying on. The plugs at the bottom of the A pillar appear dry, but right now can't unplug as car running to charge the battery. It seemed to start with the tailgate micro switch. Gate closed, hit a bump lights on. Every bump would cause an on or off situation. I kept the gate closed but pulled at it to see if the latch was lose. No, but the lights did go off. When I pushed, they came back on. So I pulled the plug to the micro switch and this seemed to tell the bloody lights to stay on, forever! Killed the battery.

I've "instructed" the car to switch all lights off. But all that went off are puddle lights.

The problem then is either a wire or the BECM. Any idea where on the BECM so I can replace the transistor?

Thanks all.
Click to expand...

You are a brave man! Marty might know or Rick the Pick.
 
Doo said:
I'm having this exact issue with the lights staying on. The plugs at the bottom of the A pillar appear dry, but right now can't unplug as car running to charge the battery. It seemed to start with the tailgate micro switch. Gate closed, hit a bump lights on. Every bump would cause an on or off situation. I kept the gate closed but pulled at it to see if the latch was lose. No, but the lights did go off. When I pushed, they came back on. So I pulled the plug to the micro switch and this seemed to tell the bloody lights to stay on, forever! Killed the battery.

I've "instructed" the car to switch all lights off. But all that went off are puddle lights.

The problem then is either a wire or the BECM. Any idea where on the BECM so I can replace the transistor?

Thanks all.
Click to expand...
You will need to run the car for a very long time to fully charge the battery.
 
Datatek said:
You will need to run the car for a very long time to fully charge the battery.
Click to expand...

I did, then I took it for a drive. Removed fuse 15 and it started 1st thing this morning. I still can't be sure if the BECM is faulty or a wiring loom fault or an earth fault....

It "seems" to have started about 6 weeks after the steam clean o_O

However, it also seems to have occurred when I fitted the new wind deflectors then got the car jet washed thoroughly...

So, could be a dodgy earth or water got into the BECM/Wiring/Multiplugs in the "A" pillars :confused:

Still, all easy enough to check, but what will I find?

And I love a good resurrection :cool::D
 
Doo said:
I did, then I took it for a drive. Removed fuse 15 and it started 1st thing this morning. I still can't be sure if the BECM is faulty or a wiring loom fault or an earth fault....

It "seems" to have started about 6 weeks after the steam clean o_O

However, it also seems to have occurred when I fitted the new wind deflectors then got the car jet washed thoroughly...

So, could be a dodgy earth or water got into the BECM/Wiring/Multiplugs in the "A" pillars :confused:

Still, all easy enough to check, but what will I find?

And I love a good resurrection :cool::D
Click to expand...
Steam cleaning the interior is death to a P38 or any modern car for that matter. There will be condensation in all sorts of places, even in the switch for the interior lights. The electronics work on low voltages and very low currents for switching, so just a little condensation will activate things.
Jet washing can also be risky if the under bonnet area is done without care.
Best I can suggest is stick a de-humidifier in the car for a few days. You could also take the BECM out of the car and leave it in a warm place like an airing cupboard for a few days.
 
Datatek said:
Steam cleaning the interior is death to a P38 or any modern car for that matter. There will be condensation in all sorts of places, even in the switch for the interior lights. The electronics work on low voltages and very low currents for switching, so just a little condensation will activate things.
Jet washing can also be risky if the under bonnet area is done without care.
Best I can suggest is stick a de-humidifier in the car for a few days. You could also take the BECM out of the car and leave it in a warm place like an airing cupboard for a few days.
Click to expand...

No no no, you misunderstand! I didn't do the interior (even I'm not that desperately stupid :eek:). No, I cleaned underneath the car! The gearbox cooler had been leaking for a while and it had run down, then back, helped by the fan and the wind at the blistering speeds I would drive...:p

So, it was coming up for mot time, I decided to bite the bullet & clean her up, trace the leak and replace the cooler.

I just wondered if steam cleaning had had an effect on the earths perhaps? Or if the wind deflectors have allowed lots of water to enter the door and into the wiring there (or the micro switches...) which could have an effect. The door still appears to be holding some water or condensation.

I'll be out checking today as it is a sunny breezy day :cool:

EDIT: But I'm still confused about the ABS & TC warning. Did steam cleaning the gearbox cause a problem or perhaps one of the ABS sensors? It only does it when going backwards. Sometimes It'll happen soon as I start to move back or it'll happen when I bump up the kerb behind me (grass bank, up the kerb onto the grass, reverse to clear the cars in front and back into "D" and away...stop...engine off...engine on, drive and clear, but Traction Control warning still appears on the dash).

I wonder if perhaps a bearing needs looked at as it only seems to happen in reverse and I am steering so when I hit the kerb it nudges the bearing? Only a guess at this point. o_O
 
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