glow plug electrics help

[weldore]

we tried...but we failed ...at least nothing got set on fire

[psychonaut]

True enough!! There's no seperate glow-plug control unit is there? The system simply relies on that sensor telling the relay that the plugs are hot enough, and cutting the current to the busbar and plugs?

As an aside, because the flange where that sensor is housed is pretty much at the top of the cooling system, can I assume that I can get it out without coolant pishing out all over my garage floor? Again?

[weldore]

it dont work like that Greg..the sensor tells the glow plug relay how hot the engine is.if its cold it will put it on for say 7-10 seconds..if its warm itll be shorter.its nowt to do with measuring the temp of the glow plugs.

and yes..only a small amount of coolant will come out if you remove it..i think you pull a clip and it comes out on them

[psychonaut]

Thanks Wellie - that's what I meant in a roundabout way, I'm just none-too-clever with these English words, being from this side of the Taff and all that

I'll pull the sensor I think, and see about replacing it. Tomorrow

[ewenmaclean]

Hello,

apologies for jumping in on the thread, but I had a look at the picture of the connector on the coolant flange, and I think possibly the fact the brown wire is cut is your problem - the yellow/red wire should go to the temperature sender, both brown wires should be earthed, and the blue/white wire to the glow-plug relay. On the junior timer connector you have going to the coolant flange, you should be able to see that an earth is associated with each of the two temperature outputs - one for the glowplugs, and one for the temperature reading on the dash.

My guess is that the brown is connected somewhere to the yellow/red wire from the loom somehow, and that the fact the yellow/red you see is earthed means the resistor is reading fine, but with the connectors the wrong way round - it doesn't matter which way you wire up a resistor.

I'd look at earthing that brown wire if I were you and seeing how long the glow phase is then

Hope that helps a bit

Ewen

[weldore]

you are bang on ewen...of course the sensor needs to be grounded because its in a plastic housing... so you have one input for the temp guage and one out to ground...then one input for the glow plugs and one out to ground...one for each resistor yes?

[ewenmaclean]

Hi Weldore,

yeah - that's it. There are two resistors there and they both need a single ground, although they could technically share the same one. The 4-pin plug is common to most vws there - even more modern ones, since tdis have one feed to the temp gauge, and one to the ecu, which then control the glow plugs.

You're right - since it's not a metal housing it needs a separate earth. Unlike in the other picture, which you correctly identified as the low revs oil pressure switch, where earth is provided by the head itself.

Ewen

[weldore]

ok Greg

to be right you need to ....

disconnect the red/yellow wire thats running to the earth on the head.

then pull apart the connection on that brown wire and take the connector off it and join both brown wires together and run them both to the earth that you took the red/yellow wire off

then get the red/yellow wire you took from the earth and connect it to the temp guage wire(the one you disconnected from the brown one)

then connect both blue and white wires together and bobs ya mums brother

we have Ewen to thank for this..

[psychonaut]

Ewen / Wellie - many thanks, I owes you both beer for this. I woke up about half an hour and the first flippin' thing that came into my head was that glow-plug light!! I'm going a bit mental with it, I swear....

Anyway, work beckons soon, so i'll try this tomorrow when I haul my idle derrière out of bed. I'll let you know how I get on.

Thanks again fellas

[weldore]

im sure you will be triumphant..unlike the kite escapades this evening

[psychonaut]

lolol - I think we need the story of the kite dude

[weldore]

well...

it was a bit breezy before we went so all was good.went to the chippy on the way for some tea and it started raining
got there and guess what..no bloody wind whatsoeva..so we were basicly making our own wind by running with the thing ..this obviously got a bit tiresome so it ended up with me resorting to driving and the lad sat in the boot with the boot lid up ..driving along a field at 10mph..in and out of ruts ..with a bloody box kite bouncing off the floor

[psychonaut]

PMSL!! I would have paid good money to see that!!

[weldore]

our lass has recorded it on her phone...for times when im trying to be clever

[psychonaut]

I think your lass needs to be posting it on here, or Facebook, or YouTube, or all three