Help! engine nearly cuts out when my lights are on!?

[madmansi 0]

Hi all,

 

My misses drove my vr the other night and commented on how the lights were crap (i ignored it as yes they're not brill plus her polo has xenons). This morning on the way to work i had a brief moment when the lights would not work, after switching them on off again they came back.

On the way home tonight cruising along the car suddenly became stuttery and nearly stalled, i changed down and after a few seconds it cleared.

I got home and had a quick play, when i put the lights on then full beamed them the car nearly stalled!

It seems a bit random, but really needs sorting!

 

Any help really appreciated

Simon

 

PS; Car has an uprated headlight wiring loom fitted by previous owner a while ago.

[g60bv 0]

pos alternator.?

[Crasher 3]

That will be fun to find, a poor earth probably but you will need to go through them all following the current flow diagram. The only problem is the headlight harness is an unknown and it could be a problem in there-who knows!

[madmansi 0]

Cheers for the replies, a bit more info;

 

This morning from cold she would'nt fire up straight away -never had this before -on third attempt with a little throttle she started and ran perfectly all the way to work.

With regard to the lights;

I have no main dipped beam, when pressing the rocker light switch to first position lights come on, in second position they dont get brighter and the light on the switch goes off (I have full un dipped beam when using the stalk).

 

Any ideas??

-dodgy light switch?

[Jim 2]

Hmmm.. you know i've not noticed whether there is a pattern with my headlights being on and my running problems. I've been using my sidelights a lot lately because of the murky weather in the morning and have ongoing running problems with bad idling, surging revs, revs sticking open, cutting out - its driving me insane.

 

With regards to the sidelights only working - open your bonnet and find the fuses plugged into the loom, switch the lights on, and carefully give them a firm prod. In my case that makes the headlights flick on. But be careful obviously!

 

I have to do this virtually every time I drive the car at night - and bizzarely they then stay on fine for the rest of my journey. Just think I need a new pair of fuses as the contacts on the old ones must be corroded to heck.

[Rpmayne 0]

To short out the battery to effectively stall the car I would have thought it would be an unfused supply shorting to ground somewhere.

 

I don't have one of these uprated wiring looms but assume these wiring looms use the original headlight supply to switch a relay supplying a larger cable supply to the lights? Are the uprated cables being switched by the relays fused at the battery or after the relay?

 

I would personally check the new loom first. Saying that I had the internal lights wiring loom to the switch burn out before with no idea as to why. Replaced it and never happened again...? So could be alot of things.

[coolrado 0]

Just think I need a new pair of fuses as the contacts on the old ones must be corroded to heck.

 

Dont you mean Relays?

even the supposedly sealed ones tend to get damp and corrode in this weather, i came back to a flat battery last week after one of the relays filled up with water and turned my left headlight on all night, i have just ordered some high current relays that i am going to put inside a watertight enclosure this time, i might even fill it with windscreen adhesive just to be sure. :lol:

[Jim 2]

Sorry, relays. Its still early.

[TomB 0]

I'd second the relay check. My old valver's 1st headlight loom eat relays on a regular basis (including turning the lights on at random & flattening the battery).

Good luck,

Tom

[madmansi 0]

Hello all,

 

Turns out it was the relay in the uprated headlamp wiring loom, got a new one from the local car parts shop for £2.99!

 

Cheers

Simon

[.A.N.T. 0]

i have just ordered some high current relays that i am going to put inside a watertight enclosure this time, i might even fill it with windscreen adhesive just to be sure. :lol:

 

Have mine in a little tupperware container with holes drilled in it for the wires. Not particularly pretty, but the ends haven't corroded in a year so it must be doing something right.

[GIXXERUK 0]

i've found the the best way to mount the relays is upside down ,so water cant get into them , the in line fuses are a pita , i use an old bike inner tube to cover these as they are a magnet for water and corrosion in this damp weather