odd electronic faults 4.6 p38. 1997

dougdotcom · Apr 24, 2011

this is a odd one, the radio only works if the fag lighter is powered by a battery booster pack, the Hevac only has the back light to the Led display nothing else showing or working on it, the electric windows don't function or sun roof or mirrors, (Tested the switch pack socket with a replacement known working switchpack) still dead.

All fuses are ok in the Becm as are the ones under the bonnet, is there a junction behind the drivers right side cover panel near the accelerator pedal from the engine fuse box that goes to the Becm plugs? this would be the cable that runs under the kick strip to feed the becm, Also has a leak from the "o" rings from the heater matrix as i can see the carpet wet just below the heater box, he also says just recently he's noticed damp under the drivers carpet too.

When connected the the Obd2 socket (faultmate) i can get all windows, mirrors, and sun roof to operate via the laptop. and no faults are stored, it dose not show the switch pack on the search.

He also told me a friend had the exact same problems as he has and when checked via circuit tester there were brakes in the wiring between the engine fuse box and the becm. I see there is a multy plug under the engine fuse box, if i remove this and the feeds to the becm should it be possible to check for brakes in the wiring or as stated at the start of the question is there a block connector behind the cover in the drivers footwelll?

Any help would be good and i will welcome any other thoughts on this

.

JohnP38 · Apr 24, 2011

dougdotcom said:
this is a odd one, the radio only works if the fag lighter is powered by a battery booster pack, the Hevac only has the back light to the Led display nothing else showing or working on it, the electric windows don't function or sun roof or mirrors, (Tested the switch pack socket with a replacement known working switchpack) still dead.

All fuses are ok in the Becm as are the ones under the bonnet, is there a junction behind the drivers right side cover panel near the accelerator pedal from the engine fuse box that goes to the Becm plugs? this would be the cable that runs under the kick strip to feed the becm, Also has a leak from the "o" rings from the heater matrix as i can see the carpet wet just below the heater box, he also says just recently he's noticed damp under the drivers carpet too.

When connected the the Obd2 socket (faultmate) i can get all windows, mirrors, and sun roof to operate via the laptop. and no faults are stored, it dose not show the switch pack on the search.

He also told me a friend had the exact same problems as he has and when checked via circuit tester there were brakes in the wiring between the engine fuse box and the becm. I see there is a multy plug under the engine fuse box, if i remove this and the feeds to the becm should it be possible to check for brakes in the wiring or as stated at the start of the question is there a block connector behind the cover in the drivers footwelll?

Any help would be good and i will welcome any other thoughts on this

.

When you turn the key to pos3 to start the vehicle,you should see the symtoms on the radio and hevac you describe.Which means the feed to the radio and hevac in key pos 2 is not being received.Could be ignition switch or anywhere else in that circuit.

Derek Ward · Apr 24, 2011

The switchpack is powered from F1 which also feeds the radio, clock, instrument cluster and footwell lamps. Are any of these (apart from the radio) working? Do the windows work with the booster pack plugged into the cig lighter socket? The earth for the switchpack is located at the back of the BECM. Possible this could have come adrift. As the windows etc are working with the faultmate, the problem has to lie with the switchpack somewhere.

The power for the radio etc come from a different connector than the switchpack. There is a splice (S205) to feed the radio etc. I don't know where this splice is though unfortunately.

According to the diagrams, there should be nothing between the engine fuse box and the above that would give you these problems. Check if the clock and the instrument pack are working OK. That would at least tell you you have power up to that splice.

odd electronic faults 4.6 p38. 1997

dougdotcom

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JohnP38

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Derek Ward

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