electrical help required

bluebaron · Post by **bluebaron** » Mon Feb 07, 2005 6:42 pm

my brother has a 1994 mk3 coupe which had a small electrical fire in the scuttle area.

after the fire with the burnt out wiring still in the car the following was happening:-

1) fuel pump under the car constantly running
2) radio turned off when you opened the door

we removed the burnt out parts of the harness and replaced them with good wiring from another polo of the same year. all the connections are good. when the battery was connected the pump didnt run, result.

turned the ignition on and there was no life from the pump at all. so the relays were checked with a multimeter, no obvious problems with the relays. next was the fuse. across the 2 wires the meter picked up around 6v (seemed odd to me).

then we checked that the fuel pump actually worked, so a feed was taken direct from the battery, +ve to +ve earth to earth and the pump ran.

upon closer inspection of the harness to the ECU the number on the replacement harness was 357906373 and on the original harness was 3A0906373 - does the fact that these number are different make a difference?

i'm quickly running out of ideas about this so any help is greatfully received.

amstrange1 · Post by **amstrange1** » Mon Feb 07, 2005 7:03 pm

What year and model of Polo did the new wiring loom come out of?

bluebaron · Post by **bluebaron** » Mon Feb 07, 2005 7:17 pm

it was a hatch in a scrap yard unfortunately, all the badges had gone and i forgot to take note of the engine numbers on my brothers car and the " donor" vehicle

metz · Post by **metz** » Mon Feb 07, 2005 10:49 pm

Are the ECU's the same shape?

As it sounds like the new wiring is out of an older polo. the 1994 car has the weird looking ecu with the soldered in chip..wonder if that makes a difference andy?

amstrange1 · Post by **amstrange1** » Tue Feb 08, 2005 5:00 pm

Absobloodyexactly Mr Metz. Guess that could be the problem - but neither of those part numbers come up on ETKA as a wiring loom. One does, but it just says it's a 'cap'. Hmm... Weird!

bluebaron · Post by **bluebaron** » Tue Feb 08, 2005 10:01 pm

looks like i'm off to the scrappy again on my day off to check the engine numbers and the ecu.

bugger

bluebaron · Post by **bluebaron** » Fri Feb 11, 2005 10:17 am

just found out that the donor vehicle was a multipoint injection, but looking at the wiring diagram in the haynes manual there doesn't appear to be that much difference to the wiring.

i've scanned the pages from the haynes and i'll post em up once i got em coloured.

bluebaron · Post by **bluebaron** » Mon Feb 14, 2005 10:25 am

Here's the pics of the haynes (with color). On the first image, fuse 1 voltage reading is around 6V, any ideas as to what could be causing this as I'm told that I should be getting 12V? The wire to the Lambda probe is a twin core wire with waht appears to be shielding on the inside of the main cover. Should this shielding be connected to itself (I had to cut it and strip it back to facilitate the reconnection of the enclosed wires)

My brothers 1.0 Coupe

Donor vehicle

ste mk1lx · Post by **ste mk1lx** » Mon Feb 14, 2005 10:40 am

I recon you've got the wrong there appears to be no inlet manifold heater system in the multi-point loom.

bluebaron · Post by **bluebaron** » Mon Feb 14, 2005 11:04 pm

Spoke to a guy at GSF, he told me to ring a bloke at my local indie vw garage who said he needed to see the car. The car doesn't move cos the fuel pump doesn't work.

RIP L2** CHD, time of death 15:07.

86C · Post by **86C** » Wed Mar 16, 2005 12:40 am

The 3A0 and 357 part numbers are actually Passat part numbers

Polo numbers for a Mk.3 start with 86 and usually a 7 thereafter for the hatch bodyshape and general Mk.3 parts. Coupe only parts had numbers starting with 871 and saloon's 873...

pete69zx · Post by **pete69zx** » Wed Mar 16, 2005 5:47 am

bluebaron wrote:RIP L2** CHD, time of death 15:07.

Funny that... my reg plate is L3** CHD (& it's a silver 1.3 CL coupe)