Technical mk 2b earth fault?

[siadz]

Hi there,my 2b passenger window has become really slow going up and down,and randomly won't start!.the starter motor turns then stops after a second or so and all the lights go really dim?also keep getting the airbag warning light on.with the low voltage fault.was thinking maybe an earth fault of somekind?any help much appreciated!!

 

[thelad]

Check battery, have it charge checked first

 

[DaveMcT]

The main earth lead is easy to check - follow it down from the battery remove the bolt clean the metal, grease with vaseline and put back. Repeat on the engine connection. But if its old the battery could have lost one cell . 10V (or less) messes up the electronics.

 

[Ziggy122]

Another Check for a Crappy Earth, is to get a negative Jump Lead, attach it to the bonnect catch and then the Negative on the battery, it'll provide an alternative earthing route, it MIGHT help tell you if you've got a problem or Not

If the engine is turning over then stopping, the motor might be stopping due to not sufficient Voltage/Amperage to Turn over, and been torque stopped hence lights going dim as the starter motor is sucking alot of current

So definatly get the battery Charged up, or a Known good battery to test starting the car with it

Ziggy

 

[DaveMcT]

TBH its better connected to the drivers side (UK) engine mount as bonnet hinges can be dirty.

 

[fingers99]

Do all that, but note that there are a number of subsidiart earth connections. You'll probably only find them all if you have a manual, but there's usually one in thhe passenger compartment, passenger side, beneath all the trim.

Only ay to "test" them is to undo, scrape clean, smear with vaseline or silicon grease, and re-fasten.

 

[Ziggy122]

earthing Points a plenty yes

1 on passenger side by the fuel cut off Switch
1 in the Driver foot well between the center column - very hard to spot actually
1 in the Boot
3 in the engine bay - Battery Post (neg) to Chassis earth - Multi plug and the Gearbox earth
I think there are a few more too

Ziggy

 

[siadz]

thanx,checked the battery,its 12v and 14+v with the engine running.tried cleaning the earth on the passenger inner wing and the thing with the jump lead.it didnt make any difference to the window.and now my airbag lights on again with the same low voltage fault!:bang:

 

[Ziggy122]

is the battery 12.0v with engine off?

i think batteries should stand at about 12.6v to be healthy

But if the Airbags are saying low voltage - then there is either a sapper or a poor circuit = Earthing fault

Ziggy