1.9dg wiring confusing me, previous bad bodges!

Post by **Ads1987** » 20 Oct 2019, 20:18

Hi Guys,

Brought a 1983 Leisure Drive fited with a 1.9dg engine, going through the fun of uncovering a lot previous bodges as is the norm with old vans, but the wiring on this one is particularly impressive! I owned a 1.7ky before so some is familiar and some isn't.

I'm hoping you guys can point me in the right direction by looking at the pics and telling me what looks right/wrong.

On a side note I've noticed the heater blower runs with ignition off and this seems like it could be a fault with the thermo wiring and ignition wiring being swapped? There also seems to be a relay missing from the engine bay, somehow the engine does run though, it's quite kangaroo-ey and hesitant and lacks power though so that's the next mission. Also Coolant low warning flashes and temp gauge stays at red hot from cold start.

I'd be really grateful if someone could point me to an early van wiring diagram if there is one, Haynes and all the links I've found only really seem to properly cover late vans with the relay boards and newer type fuses etc.

Missing relay? No ideas how if it is missing how things still work?
https://photos.app.goo.gl/enJg9xoybbJKhUBv8

Assume this is the coolant temp gauage wire and sender - currently flashes red and goes straight to overheating but have noticed blue/green the coolant low level wire is broken at sender.
https://photos.app.goo.gl/uxjFbZQVwHh5J69b8

From what I understand this is the themoswitch that puts carb in choke for cold start? has two piggy back black wires and a mystery purple wire that was loose when I got the van so no idea if it goes here?
https://photos.app.goo.gl/hPh6U8VcvKug7Gip6

Sorry for the barrage of questions but I figured alot of this is all linked so more useful to you all at once?

Cheers,

Adam.

Post by **AngeloEvs** » 21 Oct 2019, 10:49

What you need is the Bentley manual, this covers the wiring diagrams for virtually all models in greater detail. I can try to email you a copy in PDF format if you PM me your email address or see if it is available by googling it.

You have a number of wiring issues and hopefully the manual will help you to sort it.

The temp gauge will only swing fully right if there is a short circuit in the wiring that goes to the coolant temperature sender or the electronic module that senses whether the coolant level is low is faulty. If a short circuit does exist then the led will also flash. The electronic module looks like a relay and is marked 42 or 43. The first test is to remove the module and eliminate it as a possible fault. On early vans, this module is not in the fuse box but close to the fuse box on the pillar or somewhere in that area. Just remove it. Not sure of the exact location but you may find it by searching the forum for threads that cover temperature gauge issues.

Post by **itchyfeet** » 21 Oct 2019, 11:30

http://syncrosport.com/info/wiring/VW_T ... _SP_DG.pdf" onclick="window.open(this.href);return false;

Post by **937carrera** » 21 Oct 2019, 11:42

https://forum.club8090.co.uk/viewtopic. ... 1&start=45

Bit of a long thread, but this was another example of the woiring for the thermoswitches being messed up

Post by **Ads1987** » 21 Oct 2019, 12:56

Thanks itchy but that's the one for the late vans with fuse box and relay module etc. So not the same as my one.

AngeloEvs that's helpful thank you will send my email and do what you suggested.

937carrera thanks will have a read up of that thread!

Plenty to keep me busy by the sounds of it!

Anyone know if I should have a relay fitted in the engine junction box or is that only on diesels ?

Post by **itchyfeet** » 21 Oct 2019, 16:24

Ads1987 wrote:Thanks itchy but that's the one for the late vans with fuse box and relay module etc. So not the same as my one.

Sorry should have read that.

Post by **ajsimmo** » 21 Oct 2019, 16:41

Ads1987 wrote: Anyone know if I should have a relay fitted in the engine junction box or is that only on diesels ?

Yes, you should have a relay. It is switched by the thermo switch in the left hand bend in metal return pipe across top of engine. It feeds the hedgehog manifold heater, and the anti-icing heater in carb throat and/or choke heating element.

Sent from my ONEPLUS A3003 using Tapatalk

Post by **Ads1987** » 21 Oct 2019, 16:43

Ok thanks, so that's why it will run without it, will be an issue from cold start I guess. Will find one and get it on order !

Post by **steveo9007** » 21 Oct 2019, 17:50

Bentley manual online, takes while to load but its all there, i have a hard copy aswell, so any pics you need zooming in give me a shout if you want.

http://syncro.org/Files/Bentley_Manual.pdf" onclick="window.open(this.href);return false;

Post by **ajsimmo** » 23 Oct 2019, 07:26

Remember Bentley is US version, so no details of engine bay wiring for DG - it's all Digijet/Digifant.
Just use the Haynes.

Sent from my ONEPLUS A3003 using Tapatalk

Post by **davidoft1** » 23 Oct 2019, 08:58

I have a relay of you don’t find one

Post by **Mocki** » 23 Oct 2019, 17:17

The relay is required, the inlet manifold heater requires it .
The big thicker red wire from the inlet manifold heater and the carb heater thinner red connect to the relay which is switched on by the thermo switch in the metal crossover pipe .
The fuel cut off solenoid and the choke black wires all connect to the ignition switched live from the coil loom .

Post by **nesty** » 25 Oct 2019, 19:51

ajsimmo wrote:
Ads1987 wrote: Anyone know if I should have a relay fitted in the engine junction box or is that only on diesels ?

Yes, you should have a relay. It is switched by the thermo switch in the left hand bend in metal return pipe across top of engine. It feeds the hedgehog manifold heater, and the anti-icing heater in carb throat and/or choke heating element.

Sent from my ONEPLUS A3003 using Tapatalk

I didn't know there was a relay in the engine bay, is this the black box, (far left when standing behind). I run on LPG, though if there is ever a time I have to start cold on petrol, mine is a pig to start and keep running, wondering if my relay is screwed for this function!

Post by **ajsimmo** » 26 Oct 2019, 13:23

nesty wrote:
ajsimmo wrote:
Ads1987 wrote: Anyone know if I should have a relay fitted in the engine junction box or is that only on diesels ?

Yes, you should have a relay. It is switched by the thermo switch in the left hand bend in metal return pipe across top of engine. It feeds the hedgehog manifold heater, and the anti-icing heater in carb throat and/or choke heating element.

Sent from my ONEPLUS A3003 using Tapatalk

I didn't know there was a relay in the engine bay, is this the black box, (far left when standing behind). I run on LPG, though if there is ever a time I have to start cold on petrol, mine is a pig to start and keep running, wondering if my relay is screwed for this function!

That could be the reason, as manifold heating isn't really required on LPG (as it's already a gas and won't puddle like cold petrol).

Sent from my ONEPLUS A3003 using Tapatalk

Post by **nesty** » 26 Oct 2019, 16:33

Cheers, many thanks I'll take a look, as don't have issues starting cold on LPG all good, though petrol, I try to avoid by topping up LPG as when i can to avoid a petrol cold start!

Btw is it easy to buy this relay, what is it called?

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