Electrical Gremlin [Archive] - VW T4 Forum - VW T5 Forum

Electrical Gremlin

white van Al
06-04-09, 08:59
Driving back from Liverpool the other day i got within spitting distance from home and i started to get warning lights on the dash.
Firstly the rev counter dropped to zero then the oil warning light came on. Every time the counter sprung back into life the oil light went off. Also after a while the battery warning light came on but again went off when the rev counter starts working again.
Came to work in it this morning and all seemed ok again but then just before i got to work same thing happened.
Any ideas whats causing it so i dont have to spend a fortune getting a mechanic to fault find??
By the way its a w reg 1.9td if that makes any difference.

Any Help much appreciated fellas.

06-04-09, 16:51
loose connection on the alt or the alt or regulators on the way out

11-04-09, 16:30
Did you get anywhere with this?

I'm new to the forum and have the same issue, except that my rev counter is now spurious. To get it working at all I've had to re-run new wires from the small plug on the alternator (red and blue) into the plug on the other end, now I've got some jerky movement on the rev counter with the oil light flashing and alarming. Previously it would only alarm on start up because the rev counter didn't work at all.

What is odd is that if I disconnect the blue wire from the alternator I still have the jerky movement, wheras the red one loses it altogether. Does anyone know for sure if both wires are required for the rev counter to work properly?

11-04-09, 18:59
blue is the charge indicator red/colur is the rev counter

11-04-09, 21:49
try looking for loose connectors in rear of fusebox

13-04-09, 10:17
Thanks for the info. I've given it a good go and have identified what I think is the snag.

Basically with everything wired up the counter needle still jerks around but if I jiggle the plug on the side of the alternator, depending on the position it holds steady; however once I release it it starts jumping again.

I've disconnected the plug and put some tension into the female connectors and had a go at cleaning up the male connectors on the alternator but it's still no better. It appears to be a contact problem either in the plug or possibly wherever the plug terminates inside the alternator.

Short of taking off the alternator and stripping down/continuity checking I'm now stumped but a new alternator seems a bit of an extravagance especially as there are no charging issues. My only concern is that should I get a genuine oil pressure failure I wouldn't know.

Thanks again for the help, this is an excellent forum particularly being type specific; Is the tenner for the full registration worth the expense btw? With money being tight it'd be good to know that the cost would pay dividends, what does full membership get me that I don't have now?

13-04-09, 15:08
The black pastic cover comes off and the small nuts hold the regulator in place it is probably these that are loose.
Yes the subs are worth it

15-04-09, 11:58
Thanks Davie, exactly the problem; the nuts were slack as a yak.

Rev counter now steady and the oil warning light and beep has gone.....just got to try and get rid of the brake wear indicator light now and hopefully the only time I'll hear that beep again will be if I have a genuine snag....Cheers for the help once again.

15-04-09, 17:11
easy passanger wheel arch front. I shorted mine out and sealed it up no more beep beep as I have it serviced annuallly Im not worried about the wear.

18-04-09, 07:22
I'll have a look and give it a go this weekend.

18-04-09, 17:38
Found the cable in the wheel arch.

It had been severed so I thought my luck was in. I first re-attached the cables and then tried shorting out but i've still got the light and the annoying beep on start up.

Does anyone know where to look next?

Apologies for hijacking someone else's thread btw!!

18-04-09, 19:43
poor connections improve them and that should sort it

19-04-09, 07:51
Davie, when you refer to poor connections, at which point can I do anything about them.

I intend stripping back a bit of the cable where it is now hanging down anyway. The wires that were exposed, that I've now shorted out may be suspect as they looked quite corroded.

After that point when the cable goes up into the van I've got no idea where to start looking.

I've just got the T4 workshop manual but can't find anything in there to help.