Page 1 of 1

early diesel glow plug wiring

Posted: 22 Apr 2014, 19:52
by rikpal
Temp gauge not working on dash, so following wiki etc found needle didn't move when connector put to earth, so ran new cable from sender to dash, temp gauge now working but glow plug light flashes on briefly then goes out. glow plugs not heating.
from wiki I've noticed there is a blue /white wire from glow plug relay labelled to" temp sender". I'm guessing there is a connection somewhere that I've bypassed!! Does anyone know where there is a wiring diagram, or can tell me where I went wrong. : :?
Its an early type dash with temp gauge and fuel gage on left hand side, original engine was 1.6 d cs engine

any help gratefully received
thanks

Re: early diesel glow plug wiring

Posted: 22 Apr 2014, 21:28
by syncronized
Not sure about the early diesel but guessing its similar to the later in having 2 senders. One (yellow/red wire I think) connects to the temp gauge & the other with the blue/white wire connects to the glow plug relay. All that does is cut the glow plugs as the temperature rises & the sender resistance drops, so if its not connected you get full glow plugs even when hot.

Re: early diesel glow plug wiring

Posted: 23 Apr 2014, 15:16
by rikpal
So there are 2 senders, couldn't see any other so I've back tracked,
I also changed the oil pressure sensor as the seal was leaking, disconnected the wire and hey presto glow plug light comes on. put old pressure sensor on and all working fine ( must be wrong sensor).
Still surprised that sensor does both jobs, or has there been some inventive wiring going on in the past? it could also explain why the glow plug light stays on until engine is started.

Does anybody know where the second sensor is located? if not as above

Thanks for the help

Re: early diesel glow plug wiring

Posted: 23 Apr 2014, 18:15
by bigherb
It should have two sensors. The glow plug sensor is in the top hose flange on the side of the engine (blue/white wire).
The temperature gauge sensor is in the heater hose flange at the rear of the head (blue/yellow wire).
Check the wires are not mixed up especially with the oil switch blue/black wire.

Re: early diesel glow plug wiring

Posted: 24 Apr 2014, 20:31
by rikpal
finally tracked it all down, theres no sensor for the glow plugs (no sensor on top hose flange) , blue white wire has been linked to the oil pressure sensor on oil filter housing, so glow plug light stays on until engine is started.
At least that's the way it looks.

Re: early diesel glow plug wiring

Posted: 25 Apr 2014, 16:06
by Aberdeenbus
Hi,

have a look here

http://www.cs.rochester.edu/u/jag/vw/en ... plugs.html" onclick="window.open(this.href);return false;

Helped me no end with mine.

Cheers
Si