Couple of coolant electrical faults

[zak]

Hi,

Vans sat for a while and back on it but I'm struggling with a couple of faults relating to cooling. Can you help pls?
First

is flashing red light.
Ign on , light flashes few secs then off. start engine, 5 secs later flashing red on regardless of temp.

Tried with relay 43 removed and the light goes out after 5 secs as it should.

I've cleaned, tightened and reseated all the crown earths by the fuse box and any earths I could see on left side of engine bay.
Removed and cleaned coolant bottle sensor prongs, yes I've coolant. Tried weakening or strengthening the mix in the bottle.
Tightened the nuts on the back of the instrument cluster
The wires on the coolant bottle are Brown and Brown/blue and appear to disappear under the van and forward. Colours don't seem to match Bentley.

Without access to spares is there a way to test relay 43 or the Coolant level sensor

Am i on the right track, any other tips pls?

Second Problem
is the Temp gauge is reading abnormally high when engine is not. I've changed the engine but not the temp sensor. It worked before OK.
Its a Tdi conversion and I found a bunch of fuses on the YEllow/Red wire in the engine bay junction box?? I wondered are they to adjust Tdi temp sensor to T25 gauge ? Theres a 7 core from there to the ECU area, haven't got any further.



thanks again

Les

[zak]

Me me me, help me !!!

Changed the Coolant bottle sender for a new one. Still flashing !!

[Mocki]

So a couple of simple tests

with the engine cold , unplug the coolant level sender and the light should flash
"Short" the two pins of the sender plug and it should stop flashing

If it does it's the sender
If it does not ,


Is the temp,gauge rising up with a cold engine and triggering the over heating operation of the light ?

Obviously with your non standard set up that is where I stop as I can't tell what buggery has occurred .

[zak]

with the engine cold , unplug the coolant level sender and the light should flash
"Short" the two pins of the sender plug and it should stop flashing

If it does it's the sender
If it does not ,

Is the temp,gauge rising up with a cold engine and triggering the over heating operation of the light ?

Thanks Steve, with the plug shorted the light does not stop flashing. The light is flashing regardless of temperature.

Obviously with your non standard set up that is where I stop as I can't tell what buggery has occurred .

Nor can I !!!

[Mocki]

I would say you need to start at the fuse box end , and select the sender feed wires and test it there , shorting across as ou just did at the sender end, and confirm the issue is between the relay and the engine bay ....
If that is so , I would be tempted to run a new pair of wires down to the sender , and miss out all the buggery that has been applied in the past ?

[Smiffo]

That yellow/red wire/connection with the resistors in it, is the one for temp sensor in thermostat housing on my petrol, I think. ( Not sure how TDI is supposed to be wired though. )

Why are there resistors in it I wonder?
Is that a Syncro thing to have resitance in the circuit ( albeit not like that I am sure ), or an attempt to overcome another issue/fault with the wiring, or maybe even to compensate for the TDI temp sender?

If it is to compensate for TDI to T25 temp reading, it may be that the wrong resistance level has been used, so it reads higher temp than it's running at ( assuming it isn't actually running hot..!! )
I would speak to a TDI conversion chap - someone who would know what that resistance level should be.

Did you do the TDI conversion, or just swap like-for-like when you changed the engine?

Regarding red light flashing, If it doesn't stop flashing when you short the connector, then try shorting the blue/green to ground?

I am no expert though

[zak]

That yellow/red wire/connection with the resistors in it, is the one for temp sensor in thermostat housing on my petrol, I think. ( Not sure how TDI is supposed to be wired though. )

Why are there resistors in it I wonder?
Is that a Syncro thing to have resitance in the circuit ( albeit not like that I am sure ), or an attempt to overcome another issue/fault with the wiring, or maybe even to compensate for the TDI temp sender?

If it is to compensate for TDI to T25 temp reading, it may be that the wrong resistance level has been used, so it reads higher temp than it's running at ( assuming it isn't actually running hot..!! )
I would speak to a TDI conversion chap - someone who would know what that resistance level should be.

Did you do the TDI conversion, or just swap like-for-like when you changed the engine?

Regarding red light flashing, If it doesn't stop flashing when you short the connector, then try shorting the blue/green to ground?

I am no expert though

Thanks Smiffo, I welcome any input. I assume the resistors were added when the conversion was done by the garage to adjust for the TDi sender as you say. The van isn't running hot according to VagCom (Tdi geek tool) or an infra red temp sensor. I've ordered a little variable resister to try different resistance. It was working until recently.

There are different (colour) senders for the Tdi engines but Lloydy said he'd tried a few different ones on his van without success. he was also saying Brickwerks sell a standard sensor adapter to plug in the heater hose. A few options appearing.

[zak]

I would say you need to start at the fuse box end , and select the sender feed wires and test it there , shorting across as ou just did at the sender end, and confirm the issue is between the relay and the engine bay ....
If that is so , I would be tempted to run a new pair of wires down to the sender , and miss out all the buggery that has been applied in the past ?

Thanks Steve, good advice I'm sure.

[aerovolito]

I have a standard TD and had an issue with the blinking red light. It's been an intermittent fault but would only stop if I recycled the ignition. I went through and replaced temp/level sensors and checked everything else. Then I came across the gauge capacitor change on the web and that's fixed it. Took me half an hour and cost 25p.

http://www.vanagonauts.com/Warning-Light-Fix241.htm

Four years I've been staring at that bloody light!!