25 replies to this topic

[RossKnight]

Car is almost completed, and the other day I did the MK2 light conversion to my original mk3+ lights. Tail lights work fine, but the brake lights don't? Obviously they're on the same bulb so I'm assuming the bulbs are okay? Ruled the brake switch out by joining the two wires, brake lights didn't come on.

 

Also, the off side indicator doesn't work, but near side does, I tried another bulb, and still nothing, so I'm a bit lost. I did my best with my multimeter to no avail. So help on this would be grand too.

 

I'm leaning towards an earth problem maybe? The mk3+ lights had a earth wire with a spade on both light clusters, I switched these to a ring connecter and put it behind one of the bolts holding the mk2 lights in, which I'd assume is okay?

 

 

 

Any help welcome

[1984mini25]

Try the top fuse, no1 of the fuses box, should be a 35amp.

[RossKnight]

Everything else on the top fuse appeared to be working fine though?

 

I'll give it a go though, I'd rather rule everything out

[Stevie W]

Hi Ross,

 

Earthing problems usually give you wierd effects like the tail lights going off when you press the brake pedal, but it's worth cleaning up your ring terminal earths and tightening them a little more, just to be on the safe side.

It might be the problem, but the fact that the tail lights work make it unlikely. Are you sure it's just the tail light filaments in the bulbs glowing when the tail lights are on, and not both as the tail light voltage tries to find a way to earth?  

I think it's also possible to put the twin filament bulbs in wrong, might be worth checking this too.....

 

Cheers, Steve.

Edited by Stevie W, 16 September 2014 - 03:58 PM.

[RossKnight]

Hi Ross,

 

Earthing problems usually give you wierd effects like the tail lights going off when you press the brake pedal, but it's worth cleaning up your ring terminal earths and tightening them a little more, just to be on the safe side.

It might be the problem, but the fact that the tail lights work make it unlikely. Are you sure it's just the tail light filaments in the bulbs glowing when the tail lights are on, and not both as the tail light voltage tries to find a way to earth?  

I think it's also possible to put the twin filament bulbs in wrong, might be worth checking this too.....

 

Cheers, Steve.

 

Noted! Thanks, will have a go tomorrow. Unsure on the tail light situation, they came on with the lights, and looked like tail light brightness as apposed to brake lights... If that makes sense haha. I'll have a look with the lenses off.

[Stevie W]

 

Hi Ross,

 

Earthing problems usually give you wierd effects like the tail lights going off when you press the brake pedal, but it's worth cleaning up your ring terminal earths and tightening them a little more, just to be on the safe side.

It might be the problem, but the fact that the tail lights work make it unlikely. Are you sure it's just the tail light filaments in the bulbs glowing when the tail lights are on, and not both as the tail light voltage tries to find a way to earth?  

I think it's also possible to put the twin filament bulbs in wrong, might be worth checking this too.....

 

Cheers, Steve.

 

Noted! Thanks, will have a go tomorrow. Unsure on the tail light situation, they came on with the lights, and looked like tail light brightness as apposed to brake lights... If that makes sense haha. I'll have a look with the lenses off.

 

No that makes perfect sense, good luck with finding the problem!!

[Dusky]

Check the switch. Look inside the car, at the top of the brake pedal you should have something like this : 

 

Check that it's working etc, it should just tough the pedal.

 

Cheers & goodluck

[RossKnight]

Check the switch. Look inside the car, at the top of the brake pedal you should have something like this : 

 

Check that it's working etc, it should just tough the pedal.

 

Cheers & goodluck

 

 Ruled the brake switch out by joining the two wires, brake lights didn't come on.

 

[finch661]

when i converted i forgot to use the additional earthing ring connector (attached to one of the lamp unit bolts) and i had issues. I found the spare earthing wire and attached it, everything then worked!

[RossKnight]

when i converted i forgot to use the additional earthing ring connector (attached to one of the lamp unit bolts) and i had issues. I found the spare earthing wire and attached it, everything then worked!

 

There was a spade earth on each light previously, i connected a earth ring on both and bolted them to the bolts. There were also two other earth rings already in the rear loom, which I'm assuming weren't for lights, but I earthed them as well.

 

Are there any more?

[RossKnight]

Hm been up there again, still no joy. Made sure the earths were tightened, swapped bulbs over etc, changed 35a fuse, still no brake lights or offside rear indicator

 

 

hmphhh

[finch661]

have you looked at the condition of the lamp socket or the block connector? it could have failed, or the wiring from the block connector to the lamp sockets could have failed. get a multimeter out and see where the problem is!

[RossKnight]

Yeh had them apart today, they looked okay, but i might change a few things to rule it out I guess.

 

If I have the multimeter on the brake light pin on the block connector, when the pedal is pushed, should I get 12v?

[finch661]

yup, if the voltmeter is earthed to the car! if your multimeter has a conductive test, you can check if there are any breaks in the wires.

[RossKnight]

yup, if the voltmeter is earthed to the car! if your multimeter has a conductive test, you can check if there are any breaks in the wires.

 

Oh that's where I was going wrong!

 

 

 

Just kidding, yeh earthed obviously haha. It does have a conductivity test, I assume I can only test lengths of wires as long as the two probes will allow? So I can't go from the brake switch to the light?