Lights on dashboard not working and blower motor won't turn off

[Thomaswilson 0]

Hello I recently welded one of the arches of my car under the washer bottle but after putting everything back in again and connecting the wires the dashboard warning lights are not working only the gauges are working . The car radio also didn't work but I have fixed the radio it as it was a blown fuse, the blower motor also won't turn off when the ignition is on. I have took the dash apart and checked the fuses under the glove box but still can't figure it out anyone know the problem ? Thanks 

[stewal 8]

That sound possibly like a bad earth somewhere: did you disconnect the battery when welding?

 

Its possible the dash lights are trying to earth via the blower, do they light if you unplug the blower at the fan in the footwell. The blower speed is regulated by varying the resistance in the earth connection of the motor.

 

From memory I think there are earth connector blocks  in the headlight/washer bottle part of the inner wing are they clean and connected?

[Thomaswilson 0]

Hi stewal thanks for the reply I unscrewed the two earth cables and sanded them which sadly didn't turn the lights back on . Yes the battery was removed when welding whenever I was doing the tig welding I did hear a "cracking " noise coming from the dash area but all the other electronic components are working and the car starts . I unplugged the blower motor cable and it didn't help either any other ideas ? 

[stewal 8]

Thomas: the only other thing I can think of is the infamous brown plug which connects the engine sensors to the dash loom and is above the gearbox in the area you were welding. The contacts in that large multiplug are notorious for making bad connections so could be worth a look. Effectively the sensors earth the lights so if it is not connected well they will not work.

 

If you can reach up to the oil pressure switch (not the larger sender) unplug it and connect the spade connector of the plug  to a good earth then with the ignition on the lamps should light. If they dont light then you either dont have 12v positive in the instrument pack or the continuity of the cable from the instrument pack to the sensors is broken somewhere.

 

I dont like the sound of the cracking noise from the dash whilst welding - if all else fails it would be a good move to take the instrument pack out and check the circuit board on the back. I don't have the circuit diagram to hand but from memory there is diode (one way electrical switch) soldered to the back which would not survive large voltage spikes. It Is there to allow only one of the warning lights to come on after start up not both (high temp or low oil pressure). 

 

Similarly, the fan speed is varied by the transistor pack in the footwell and that too would not like voltage spikes but to be honest if you removed the battery then all of those should have been out of circuit.

[stewal 8]

Just another thought: is the handbrake warning light working?

 

if it is, it suggests there is 12v+ve at the instrument pack.

 

if it isn't, and all the fuses are ok then I would pull the instrument pack out and investigate.

 

By the way, when you checked the fuses did you do it with a meter rather than visually.

 

They can fail in such a way that they look ok but have actually blown.

 

 

[Thomaswilson 0]

3 hours ago, stewal said:

Just another thought: is the handbrake warning light working?

 

if it is, it suggests there is 12v+ve at the instrument pack.

 

if it isn't, and all the fuses are ok then I would pull the instrument pack out and investigate.

 

By the way, when you checked the fuses did you do it with a meter rather than visually.

 

They can fail in such a way that they look ok but have actually blown.

 

 

Hello again I checked the fuses quickly last time with a multimeter and current was flowing through them and replaced the fuses but didn't make any difference . Also checked the 4 cables going into the clocks and got 12v off 2 of the cables . I had a look for the "brown multiplug " but couldn't find it near the gearbox mine is a automatic by the way in case it has a different loom . Here is a picture of what I saw below . The sensor on the bottom of my sump does not have a cable attached to it I noticed this the last time I changed the oil on it . I am debating on weather all the bulbs could be blown on the clocks but would they all blow at once ?  And the handbrake warning light does not come on only gauges are working atm

[bacardincoke 42 1 Cars]

Some of the issues you're having are very similar to ones I had also...

 

Have a read at this, it may help or at least put you in the right direction.

 

https://www.205gtidrivers.com/forums/topic/174515-steel-sump-sensor/

 

Below is an image I took of my brown plug... sorry it's so poor, but it was only taken as a quick reference when working with the wires, it'll maybe show you what you're looking for -

 

 

 

 

[stewal 8]

Ah I didnt realise it wasnt a gti:  there are more fuses under the bonnet not just in the glovebox. There may be some in that box by the power steering reservoir.

 

Also do you hear a relay clicking when you put the ignition on: the ignition contolled relay is on the main fuse board of gti's and is presumably the same in yours.

[Thomaswilson 0]

On 8/25/2020 at 8:05 AM, stewal said:

Ah I didnt realise it wasnt a gti:  there are more fuses under the bonnet not just in the glovebox. There may be some in that box by the power steering reservoir.

 

Also do you hear a relay clicking when you put the ignition on: the ignition contolled relay is on the main fuse board of gti's and is presumably the same in yours.

Hey sorry for the long reply time I have been busy but finally got the dash lights sorted ! Turns out they were all blown so I ordered 20 new ones for £5 and that's sorted it . Haven't got much further with the blower motor but I've heard you have to replace the resistor but it's £50 so I'll just replace the transistor on it .