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Topic: 1.8 20vt converted temp light led flashing  (Read 739 times) previous topic - next topic

1.8 20vt converted temp light led flashing

Hi All, Just joined and recently purchased a 1991 1.8t AUQ converted mk2 gti.

Although the mechanicals seem ok, the wiring leaves a lot to be desired & is a bit of a lash up but I was aware of this, I'm slowly working my way through it.
Right from cold start the car coolant temp reads hot within 5-10mins & the red overheat led starts flashing straightaway. I have checked the actual running temps and its all fine, even after a long drive so I know its a wiring / sensor issue. The previous owner stated that it must have the wrong sensor in it as its always done this but couldn't give me anymore info about it.

So, my question is, has anyone else had this problem after a conversion? Which sensor do I need to be looking at? I'm assuming the sensor in the front rad is for fans & the sensor around the stat is for the ecu & gauge?
Any help would be appreciated, Thanks.

Re: 1.8 20vt converted temp light led flashing

Reply #1
I'm assuming the sensor in the front rad is for fans & the sensor around the stat is for the ecu & gauge?
Any help would be appreciated, Thanks.

Yes,
MK2 GTi originally would have had 2 coolant sensors (excluding rad sensor) blue 2 pin sensor for ECU and a black 2 pin for guage.

Its possible the MK4 sensor for clocks works at a different rating to the MK2, this will probably be mentioned in some conversion guides.
It's probably worth checking the guide anyway.

Re: 1.8 20vt converted temp light led flashing

Reply #2
Thanks for the reply. I've done a little more digging online this afternoon & stumbled across the clubgti forums, very useful info on there.
It seems if you use the mk4 sensor with the mk2 clocks it will indeed read 'high', installing a 33ohm resistor inline to the clocks will bring it back inline with what vag.com reads the actual temp is.
I'll try this out and report my findings incase it helps anyone else in the future.

Re: 1.8 20vt converted temp light led flashing

Reply #3
Hello!

You're correct, I've done a couple of conversions now and can confirm the 33ohm resistor trick works a treat.
Mk2 Driver
Mk2 Silver 8v
Corrado G60 Turbo
Mk2 Red 8v
Mk2 Grey 16v
Mk2 BBM ABF
Bora 20vt
Mk2 Green VR6
Mk2 Green ABF
Mk2 BBM 20vt
3.2 TT Roadster
Mk2 Red 16v
225 TT Coup
3.2 TT Coup
Mk4 Anniversary
Mk7 Red GTI Performance
Mk2 Red GTI Restoration

Mk2 BBM R32
911 Carrera 4S

 

Re: 1.8 20vt converted temp light led flashing

Reply #4
Great, Thanks for confirmation. Resistor ordered.