Loose Wires

[T25vanman]

could anyone tell me what the loose wires are for please in the picture. its a 1.6 Diesel non turbo engine.

red and yellow?
Blue and yellow (or white)?
brown one wrapped around the fuel line?
and thinner brown one to the right and down?
also what is the sensor for sticking from the housing? does a wire connect to it and how?
there is also one of those on the underside of the hose you can see going into the back of the head (in the pic its the in the underside of the hose that is directly under the taped up part of the red and yellow wire)




all help very much appreciated please.

[MidLifeCrisis]

red and yellow? This is the coolant temp signal wire
Blue and yellow (or white)? This is most likely the engine temp sensor for the glow plug system, according to my wiring diagrams
brown one wrapped around the fuel line? Brown wires are usually ground wires (which might explain why it's wrapped around a 'metal' fuel line!! But chr!st!! That's quite a bodge!! Even I wouldn't do that!!)

Finally I'm also going to assume that one of those sensors is your coolant temp sensor and the other one is your glow plug engine temp sensor - hopefully a diesel person will be along to tell you which is which????

[T25vanman]

red and yellow? This is the coolant temp signal wire
Blue and yellow (or white)? This is most likely the engine temp sensor for the glow plug system, according to my wiring diagrams
brown one wrapped around the fuel line? Brown wires are usually ground wires (which might explain why it's wrapped around a 'metal' fuel line!! But chr!st!! That's quite a bodge!! Even I wouldn't do that!!)

Finally I'm also going to assume that one of those sensors is your coolant temp sensor and the other one is your glow plug engine temp sensor - hopefully a diesel person will be along to tell you which is which????

Thanks Mid, if the red and yellow one is my coolant temp wire, where's it meant to go to?
in fact I have no idea where they are all meant to attach to. or how. haha
I can't claim the bodge job Im glad to say.

[boatbuilder]

Whenever I figure this out I'm gonna do up a diagram of it all.

[MidLifeCrisis]

red and yellow? This is the coolant temp signal wire
Blue and yellow (or white)? This is most likely the engine temp sensor for the glow plug system, according to my wiring diagrams
brown one wrapped around the fuel line? Brown wires are usually ground wires (which might explain why it's wrapped around a 'metal' fuel line!! But chr!st!! That's quite a bodge!! Even I wouldn't do that!!)

Finally I'm also going to assume that one of those sensors is your coolant temp sensor and the other one is your glow plug engine temp sensor - hopefully a diesel person will be along to tell you which is which????

Thanks Mid, if the red and yellow one is my coolant temp wire, where's it meant to go to?
in fact I have no idea where they are all meant to attach to. or how. haha
I can't claim the bodge job Im glad to say.

I'm not a diesel owner so can't say for sure but the sensor in the middle of your pic looks very much like the sensor that I have for coolant temp but I wouldn't like to guarantee it - it usually connects with a simple spade connector.
As a simple test - touch the red/yellow wire to the engine block (with the key turned in the ignition) and you should see the temp needle go to full 'hot' - that would at least prove that it was the correct cable and that your temp gauge works at least ....

[T25vanman]

red and yellow? This is the coolant temp signal wire
Blue and yellow (or white)? This is most likely the engine temp sensor for the glow plug system, according to my wiring diagrams
brown one wrapped around the fuel line? Brown wires are usually ground wires (which might explain why it's wrapped around a 'metal' fuel line!! But chr!st!! That's quite a bodge!! Even I wouldn't do that!!)

Finally I'm also going to assume that one of those sensors is your coolant temp sensor and the other one is your glow plug engine temp sensor - hopefully a diesel person will be along to tell you which is which????

Thanks Mid, if the red and yellow one is my coolant temp wire, where's it meant to go to?
in fact I have no idea where they are all meant to attach to. or how. haha




I can't claim the bodge job Im glad to say.

I'm not a diesel owner so can't say for sure but the sensor in the middle of your pic looks very much like the sensor that I have for coolant temp but I wouldn't like to guarantee it - it usually connects with a simple spade connector.
As a simple test - touch the red/yellow wire to the engine block (with the key turned in the ignition) and you should see the temp needle go to full 'hot' - that would at least prove that it was the correct cable and that your temp gauge works at least ....

YeeHaa!! Just tried and and the needle moved. There's one step forward. Cheers bud.
But where should it be wired to exactly?

[MidLifeCrisis]

Someone with a diesel,engine will be along soon to tell you (hopefully?!?!)
It's going to be one of those two sensors that you have found but I'd assume it's important that you get the right one - so best wait until someone pipes up with an answer;

FYI - it's also worthwhile putting the vehicle type, year and engine type in your signature (in 'User Control Panel') so that those answering your questions can easily see what you have

[T25vanman]

FYI - it's also worthwhile putting the vehicle type, year and engine type in your signature (in 'User Control Panel') so that those answering your questions can easily see what you have

Good shout mate. Thanks

[T25vanman]

Does anyone know which sensor the red and yellow wire (for temp gauge) attaches to and what kind of connector is used please?

[marlinowner]

Can't comment on which sender is which, but the sender in the photo uses a standard spade connector which goes on "sideways".

[colinthefox]

As MidLifeCrisis ssaid the yellow/red wire goes to the coolant temperature gauge sensor which is the one in the flange with the fat hose going to it. It uses an ordinary female 1/4inch uninsulated spade connector which slides "crossways" onto the stubby thing that looks like it is a small drawing pin.

Blue/white goes to the coolant temperature sensor for the glow plug relay which is the one in the flange at the back (towards front of van) of the cylinder head with the smaller heater hose connected to it.

As previously said, browns are normally ground connections and should be connected to the chassis somewhere.............but not via a fuel pipe!

Marlinowner types quicker!

[T25vanman]

A couple more steps forward. That's brilliant!! Thank you so much.

[syncroandy]

The engine in the pic has the 'early' type connectors on the temp senders/switches which use a simple spade terminal.
However the engine in OP's signature is a 1990, which surely would have used the 'late' type rectangular plastic connectors ?

I suspect the vehicle may have had its engine replaced with an early one at some point, and they just left the early metal flanges with their screw-in senders on the engine, and bodged the late-style harness connectors (cut them off) to work with the early senders.

'Late' wiring diagram is here:
http://syncrosport.com/info/wiring/VW_T ... _KY_JX.pdf

In any case, the yellow/red wire is for the temp gauge, the blue/white wire is for the glow-plug relay in the junction-box. Each of these connects to a sender on the coolant flange, the sender is the same for each of these circuits so it doesn't matter which way round they're connected. Each would have had a brown earth wire, which is redundant if the early-style single-pin senders are being used, as they earth through the engine block. Just make sure the engine harness earth is connected to the chassis or engine-block somewhere and you should be fine.

[boatbuilder]

Here is my 84 with a CS 1.6 engine.
Will update wire colours etc after I have a look at the Bentley manual!

[T25vanman]

Ive made a little more progress now.

I've identified the guage wire, and checked it works and have now wired it up to the correct sensor so it responds to the temp of the coolant.