Hey, a few days ago i started having a serious problem with my interior illumination. I`m talking about the dashboard lights , button lights and heater lights. They stopped working. when i switch the button of headlights nothing is happening. Headlights work, everything is working fine in the car, but the interior lights are off. I checked all the fuses ! ALL OF THEM! are intact and working. So no faulty fuse. Today! i was amazed to see that the lights turned on for a few hours and then they got off again. Something is wrong. Would it be a loos hearth wire? or what is going on. Where do i need to look to diagnose this problem. Please help, i can`t drive at night without dash lights. Thank you.

I'm guessing you have a 6N ?? if so check the dimmer control by the main light switch it might have a dodgy connection on the variable resistor

Yes is a Polo 6N from 1996, the dimmer is on FULL, when it worked i tried to scroll it up and down to see if it was bad or something, but it dimmed the light and and worked fine, i left it on full, and 2 hours later the light went off again! without me touching the dimmer again. Do you have any idea where the earth wire is for that harness ? I will will use a multimeter to see if the earth is good. i`l connect the positive wire of the harness and touch the body of the car, if that dose not have any success it means there is no power going to the wire. The power comes from the main light switch ? i assume that the power comes from the battery, and the main light switch is responsible in sending the power to all lights in the car. Dashboard buttons and heater lights?

 

What do you think?

There is an earth point on the lower part of the "A" pillar, but not all the backlighting (Hazzard switch & Heater control panel only)  use that earth point, many use the fuse/relay box as the earth along with the dimmer control unit, the earth for the speedo display is through the fusebox and actually grounds on the engine cylinder head.

 

I think i managed to fix it. I took the main light switch apart, to see if anything is broken. Everything was ok! the dimmer was smooth and working. Then i got a bit angry and i shoot a bit the wire harnesses that are in the dashboard. After that i tried to turn the lights on, well they actually worked. When they ware on i kept moving the wires then the light went off again. The problem was the wire plug that connects to the back window

defogger, a wire within that harness was moving with the vibrations of the car and connecting and disconnecting the button. The strange thing is why it was cutting all the lights off, do you think there is some kind of a short protection build into the car? like as soon it detects a spark or something it shuts off the lights? i tried to move the wires around with the lights on but it did not come back to light , only if i turn off and then turn on the main light switch again. Only then the light came on. If there was no protection i assume the lights needed to keep flickering when i was moving the wires.

 

Eh... so the problem was that stupid wire, i think is the largest one in that connection, so i placed the defogger button two slots down the center console that way the wire harness behind stays a bit more secure and not moving that much with the car. IF that still moves i`l get my zip ties and they should to the trick.

 

Thank you for the support, i`l be here for the next problem i find. :)