Water temperature gauge working sometimes

[Woodgrub]

Hi All, My Mk4 GTI has developed a problem where the water temp gauge is only working sometimes. I have wriggled all the electrical couling (I think). As there apears to be a couple of sensors could someone please head me in the right direction as to what to check or change.
Also have a problem with Drivers side door light isn't working, I have checked globe. Is the earth switch fitted in the door lock?

Regards
Woodgrub

[Back Door Shenanigans.]

The water may have something to do with if its the old coolant temp sender. See here

The switch for the door light is in the door lock modules which is inside the door skin. It's a common fault aswell. Mine was due to the plunger on the 4th micro switch failing, Cheap but semi difficult fix. Do you get an alarm if you leave your lights on with the door open. If no then its the lock module. See here

[Woodgrub]

Hi, Thanks mate. I will change the sender unit now I know which one it is and I will check door lock module.

Kind regards
Woodgrub

[leighaus]

Coolant temp senspr (see my build thread), easy change.

And your thermostats probably on the way out. Again cheap diy, but it's a bitchto get the housing lower nut off.

[Woodgrub]

Hi As I am new to this, can you tell me how to find your build thread. I tried a couple of times but no luck, takes me back to my question.

[leighaus]

New ride: '02 MK4 GTI

Easy to do yourself. It's located on the heater hose on the passenger side of the block. You can order replacements from eBay etc etc.

[Woodgrub]

Hi mate, bought new sender and fitted, all appears fine. Now just have to fix drivers door switch.
Thanks for everyone's help.
Regards Woodgrub

[leighaus]

your issue may be related to the wiring loom that enters the door. Be VERY careful with this, as if you open your drivers door and dont action the ignition barrel and close your door again.... the immo will re-arm itself. Big issue if your keys are on the drivers seat like mine were.