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Discussion Starter #1
Here’s my situation: got water into the pack and the windows, mirrors and sunroof started acting, until they gave up totally. I pulled out the pack, all 12 and 5V power seems correct, the IC seems to follow all the switch actions correctly and I’m getting both 5 and 12V at the regulator exactly as excpected. Yet the light bulb is dead and none of the switches work. I checked out the rear window cancel switch and it seemed super clean so I haven’t opened the other ones. Mirrors work normally when switching to reverse and back.

Any ideas where the 12V for the light bulb might die along the way? I suppose there is only one 12V power feed into the pack?

br,

Robert
 

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1995-2002 Range Rover P38A
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Since the switch pack sends a serial signal to the BECM, I would look for problems in the output.
As you say you were able to check the outputs from "the IC", You sound like you would have the gear to look for the serial output signals?
 

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The single light bulb is wired into the dash light circuit and has feed in the main harness for the centre pack. There is window switch pack repair stickie at the top of this forum. Sometimes these packs just give up even when they stay dry. Although cleaning all the switches can be done I would never spend that much time. I've had one fail I just purchased a known good one and replaced it.
 

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LEGACY VENDOR
1995-2002 Range Rover P38A
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4,215 Posts
There are 2 usual failure modes for the window switchpack... One the switches fail, which is what I did the writeup on repairing and is in the sticky section.

The second is more complex, as it involves failed tracks/through board connections on the PCB which have corroded and broken a circuit, which then stops the switchpack from communicating with the BECM properly - whether all your switches work or not.

The illumination for the switchpack, as RRTH mentions, is on a separate wire and is switched from the BECM, rather than internally in the switchpack.

If you have 12V feed in, a good ground, and are getting 5V out of the regulator, then the issues will be a bad track/through board connection which has caused it to fail.



I repair switchpacks in the UK and sell them on exchange for the dead one back, so have pretty much seen every failure mode of these units - and out of 30-40 of them now, I've only not repaired 2 - because there has been some major PCB damage from where someone has had a go with trying something before.

If you have the electronics knowledge to repair through board connections etc, then my advice would be to inspect all of these closely.

Hope this helps,
Marty
 
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