Hello and help! I need a wiring diagram!

Post by **asahartz** » 26 Nov 2007, 18:45

Hello everyone, my name's Chris and I've just bought my first VW, a T25 watercooled 1.9:

[img:400:300]http://www.b0lus.com/images/cars/vw/samantha1.JPG[/img]

She's misbehaving a lot right now; all manner of electrical problems, and I could really do with a wiring diagram.

Yesterday I fixed the dash lights and installed a stereo. However even though I checked what I was connecting to with a multimeter (and I'm an ex-sparky), the radio loses its settings if the ignition is off for more than a few minutes. But at the end of the day everything else was working right.

Today I went to work in her, drove to a meeting, drove to the shop. At the shop she refused to turn the starter at all - not for the first time this weekend, but I though I'd fixed it. After half an hour of fruitless wire-fiddling, she suddenly started. I switched the headlights on; the dsah lights went out. The radio went off. The indicators stopped working. The wipers wouldn't work either. I was so nervous that she wouldn't start again I just drove home regardless!

I'm a fully competetent electricion, but without a diagram I'm just shooting in the dark; as an '84 bus the wiring has been mucked about with by bodgers in the past and it's like a birds nest under the dash.

Samantha is going nowhere until I'm happy I've fixed it properly, even if that means rewiring it all! Can anyone point me in the direction of a diagram?

Post by **Westy.Club.Joker** » 26 Nov 2007, 18:50

Bentley (OE VW) manual has the wiring diagrams that will cover your van. They are about £60 but cover everything about the thing (except turbo-diesel engines)

There are a few spurious CD copies doing the rounds

Post by **Dan Wood** » 26 Nov 2007, 19:12

The haynes manual also has wiring diagrams that are mostly correct for the pre-1985 wiring.

The rats nest you mention is probably as it left the factory though - nice bundles of cable threaded here and there! It's worth giving all the connectors a damn good clean, as they can look ok physically, but be a little furred-up and high resistance. (Especially if your windscreen has leaked in the past!)

If you haven't found it yet, to the left of the fusebox on the pillar is a major earthing point. Start there and clean it all up. Take the silly pointy fuses out and check that the holders are clean and bright. We managed to melt our fusebox cover just because one end of the fuse holder was dirty!

With patience and a multimeter, it will all start to come good. There's not that many circuits on the pre-1985 models! (Which is why things always break in groups!!)
Have fun!

P.S. On the starter front, have a look at the state of the thin wire on the back of the solenoid. A favourite for corrosion, and symptoms are often "works fine one day, nothing the next!"

Post by **Mocki** » 26 Nov 2007, 19:19

also with reference to the non starting when you turn the key, check the switch itself, often the cause on intermittent nogoness

Post by **asahartz** » 26 Nov 2007, 19:40

Thanks for the tips. I don't think it's the switch, as the relays click when I turn it, but I'll take a look.

Haven't crawled under to see the solenoid wiring, but the Green Flag man did on Friday and commented that the starter looks new - didn't mention the wiring though.

The earthing point is a bugger to get to, isn't it? I don't like spades for earths, I can see me chopping them all off in favour of loops to bolt to the body. Might even replace the entire fusebox too; pointy fuses are nasty, and you can't easily see which is which anyway. Good job I work near VWP!

If that's how the wiring is from new, it will end up a whole lot better when I've done with it! My main automotive passion is Minis, not without their own wiring issues, but I have one that's 40 years old, the wiring is much neater, mostly original (except where I converted the starter and alternator), and all working reliably!

Post by **Rozzo** » 26 Nov 2007, 20:30

asahartz wrote: My main automotive passion is Minis, not without their own wiring issues

spit on the fuses and it will be fine

Post by **madmyk** » 27 Nov 2007, 03:09

Where are you?

Maybe someone close could pop along with a book?

Myk.

Post by **tonytech** » 27 Nov 2007, 09:14

Your radio loosing its settings problem is almost cirtainly down to the way its wired.
Most radios need a permanent +ve feed for the memory.
They have a separate +ve feed for the actual operation.
It sound like you have wired both to the ignition switched +ve.

Was it the first time you had used your head lights?
Check the earths behind the grill.

T