Glow Plug Light....

for questions and answers about alternative power transplants on the T25, GTi, Porsche,Subaru etc, this is the place. You must register to post but anyone can read.

Moderators: User administrators, Moderators

Post Reply
sundial
Registered user
Posts: 43
Joined: 02 Jul 2007, 20:45
80-90 Mem No: 4778
Location: Devon's Atlantic Coast...

Glow Plug Light....

Post by sundial »

hi

I guess its simple but..

I have just replaced all my water pipes etc on my AAZ diesel...

Why...does my 'glow plug light' know take ages to go out.even when the engine is warm?

Am I right in saying that the glow plug relay is controlled a temp. sensor on the coolant system?

I'm sure if I investigate it I can resolve it but maybe a simple answer may safe some time...

many thanks Keiron

User avatar
ewenmaclean
Registered user
Posts: 293
Joined: 16 Nov 2006, 19:32
80-90 Mem No: 7306
Location: Edinburgh

Re: Glow Plug Light....

Post by ewenmaclean »

Hello,

the glow plug duration is controlled by a water temperature sender on the head - there are a few different implementations depending on the engine, but it's always a white/blue wire that goes to the glow plug relay from the temperature sender. If it's taking ages to go out it's because it's not connected - it's possible you've not plugged it in again, the temperature sender has failed or the wiring is loose, or possibly the system is not yet fully bled yet and the water isn't reaching the temperature sender. The sensor on mine is a 4-pin plug on the flange on the head - if it like this you also need an earth connected, so worth checking this hasn't been disconnected - if you find the white/blue wire it should lead you to it!

Good luck

Ewen

sundial
Registered user
Posts: 43
Joined: 02 Jul 2007, 20:45
80-90 Mem No: 4778
Location: Devon's Atlantic Coast...

Re: Glow Plug Light....

Post by sundial »

thanks Ewen, I was sort of hoping it was like this, all the the plugs/sensors 'look' intact but knowing it was working ok before I'm sure I'll find it with a little more effort..

User avatar
ringo
Registered user
Posts: 2245
Joined: 14 Oct 2005, 05:41
80-90 Mem No: 1375
Location: Nottingham

Glow Plug Light....

Post by ringo »

Bet it starts better when warm though?

Ringo
Now driving a big bad VW LT Florida.

Grumpy Midget

Re: Glow Plug Light....

Post by Grumpy Midget »

ringo wrote:Bet it starts better when warm though?

Ringo

Does Yourssssssssssssss-------------------------- :mrgreen:

sundial
Registered user
Posts: 43
Joined: 02 Jul 2007, 20:45
80-90 Mem No: 4778
Location: Devon's Atlantic Coast...

Re: Glow Plug Light....

Post by sundial »

I guess I've found the problem....

Please correct me if I'm wrong....

The sender is located on the rear of the head within the flange for one of the heater hoses..?

It has a red/brown? wire and a blue/white wire..

The Blue/white wire returns from the sender but is hanging loose out of the loom with a proper VW inline yellow connector on it?

I cannot find the other end of this connector anywhere, therefore it looks like my problems diagnosed..but not resolved!!

but, I'm sure its alway been like this and I know my glow plugs used to switch of earlier, especially when the engine is warm....


Any ideas may help...........

Ta , Keiron

User avatar
ewenmaclean
Registered user
Posts: 293
Joined: 16 Nov 2006, 19:32
80-90 Mem No: 7306
Location: Edinburgh

Re: Glow Plug Light....

Post by ewenmaclean »

Hello,

that white/blue wire goes to the T pin of the glow plug relay - it goes through a 3 pin connector in the black box in the engine bay first - see if you can trace the other end of it from the relay. I don't know the exact sensor you've got but the other temperature sender is yellow/red which goes to the temperature gauge - not sure what the red/brown wire is connected to I'm afraid without seeing your setup.

Hope you find the other end of the white/blue wire

Ewen

sundial
Registered user
Posts: 43
Joined: 02 Jul 2007, 20:45
80-90 Mem No: 4778
Location: Devon's Atlantic Coast...

Re: Glow Plug Light....

Post by sundial »

Just to conclude...

Cut back to wiring loom earlier and found the other end of the missing wire.....

All good again and working well..

Must say though, due to time I didn't change the water hose's myself, I could assume that the wire may hve been snagged and damaged accidentley by the mechanic...



Never mind, all sorted know, thanks to Ewen for the help... :) :)

User avatar
ewenmaclean
Registered user
Posts: 293
Joined: 16 Nov 2006, 19:32
80-90 Mem No: 7306
Location: Edinburgh

Re: Glow Plug Light....

Post by ewenmaclean »

well done for sorting it, and thanks for the follow up post :ok

User avatar
steveo9007
Trader
Posts: 318
Joined: 21 May 2019, 17:49
80-90 Mem No: 16902
Location: Cornwall

Re: Glow Plug Light....

Post by steveo9007 »

I Have this connection in my engine bay please see pics below, the wiring goes to the electrical box in engine bay, the connector is red and has Blue/white and brown wire coming from it, on my engine itself from the coolant tank there are 2 connections available one has the temp connector connected and the other one doesn't, am i correct in assuming this is the glow plug sender ??

Image

Pic above is the connector which has not been connected since i owned this vehicle. Below shows the 2 connections on the coolant pipe mounting to the cylinder block.

Image

Should this connector with red plug on be connected, i have never seen my glow plug light on dash light up, what potentially could happen if i plug this in, any help appreciated but i think i am in the right area when it comes to the glow plug sensor as the colour of the wires match what is showing in my Vanagon repair manual.

i am hoping because the original engine was a 1.9 petrol and that the person who changed the engine to a diesel forgot to plug this in or didn't cos it caused a problem(I don't know who done the engine conversion btw).
1985 RHD Pop Top Autosleeper, 1.7D KY Engine 4 Speed ALD Gearbox (Bertie)

User avatar
steveo9007
Trader
Posts: 318
Joined: 21 May 2019, 17:49
80-90 Mem No: 16902
Location: Cornwall

Re: Glow Plug Light....

Post by steveo9007 »

Further update to my glow plug light not coming on, i have testing the glow plugs with a ammeter and a light wire and they all check out good for light and 36 amps as i have the silver nuts on top, each glow plug lights the wire when connected from ground to each plug with the bus bar disconnected so they all good. so i don't think my problem is in the engine bay. I have checked the fusebox and all 12 fuses are in tact, i have 1 blade fuse rated at 10 amps to the right of the bullet fuses and that's ok, to the right of that i have 2 white bullet fuses and they are ok, is there anywhere else i should be checking...perhaps maybe the dash panel is the faulty bit and not wired up to receive a signal to light the glow plug led..i aint sure
1985 RHD Pop Top Autosleeper, 1.7D KY Engine 4 Speed ALD Gearbox (Bertie)

User avatar
Oldiebut goodie
Registered user
Posts: 7243
Joined: 18 Apr 2008, 01:19
80-90 Mem No: 11135
Location: Eastern Angle

Re: Glow Plug Light....

Post by Oldiebut goodie »

Are you certain that the dash has been set up for diesel? If it is still a petrol dash it will not have a glow plug light and wiring to start with.
1.6D 2019 VW T-Cross
200hp VW T6
1̶Y̶ ̶1̶9̶8̶7̶ ̶H̶i̶-̶t̶o̶p̶ ̶C̶a̶r̶a̶v̶e̶l̶l̶e̶
5̶0̶8̶d̶ ̶M̶e̶r̶c̶

User avatar
steveo9007
Trader
Posts: 318
Joined: 21 May 2019, 17:49
80-90 Mem No: 16902
Location: Cornwall

Re: Glow Plug Light....

Post by steveo9007 »

Defo got the yellow light on dash, have done some more investigating and it seems I don’t have the wire in position 14 of the connector block so it seems I am going to have to wire this in myself. Everything in the engine bay is all there and connected to the relay and this does click when ignition on. Can I assume that the plugs will work albeit i won’t know cause I have no light ??
1985 RHD Pop Top Autosleeper, 1.7D KY Engine 4 Speed ALD Gearbox (Bertie)

User avatar
Oldiebut goodie
Registered user
Posts: 7243
Joined: 18 Apr 2008, 01:19
80-90 Mem No: 11135
Location: Eastern Angle

Re: Glow Plug Light....

Post by Oldiebut goodie »

Still a petrol dash then and isn't set up for a diesel.
1.6D 2019 VW T-Cross
200hp VW T6
1̶Y̶ ̶1̶9̶8̶7̶ ̶H̶i̶-̶t̶o̶p̶ ̶C̶a̶r̶a̶v̶e̶l̶l̶e̶
5̶0̶8̶d̶ ̶M̶e̶r̶c̶

User avatar
steveo9007
Trader
Posts: 318
Joined: 21 May 2019, 17:49
80-90 Mem No: 16902
Location: Cornwall

Re: Glow Plug Light....

Post by steveo9007 »

Oldiebut goodie wrote:Still a petrol dash then and isn't set up for a diesel.

Yep sure is, i am getting my head around the setup as i am converted tired foil wiring with a printed circuit board one and i need the wiring correct. :ok
1985 RHD Pop Top Autosleeper, 1.7D KY Engine 4 Speed ALD Gearbox (Bertie)

Post Reply