Aftermarket HID Using relay harness.
 

Has anyone upgraded halogen projectors to HID and used a relay harness instead of directly powering the ballasts and burners from the headlamp power feeds?

I'm asking as I've been using a HID kit for a while that should work OK without a harness. Recently though I've had many more occurrences of the engine stopping when switching the lights on with the engine running. So much that I've temporarily reverted to the Halogen bulbs.

I've got a relay harness but I'm not sure how I go about making the offside headlamp not cause a bulb failure warning with nothing connected to the bulb plug. I'm also not 100% sure that I won't get a bulb out warning using the relay powered from the nearside light.

Hi.
I used this kit on my mk2 zt with halogen projectors.
https://www.hids-direct.co.uk/h7-35w...onversion-kit/

No issues at all. No canbus bulb errors.
I didn't use a relay harness because of the reason you said. It only takes its power from one lamp so bulb out warning would happen.
Do your headlights flicker or go off intermittently?
Have read about this fault before on hid planet forum and it was a bulb shorting in the lamp unit causing the engine to cut out.
Worth a look..
I can say the kit I got from the above link works bang on. Nice bunch to deal with as well.

Same kit as I'm using. Did this last Autumn I think it was - switch on lights -engine Cut's out. Now it does it every time. If it's a short I'm surprised that it hasn't blown any of the lighting fuses. I've got both setups off the car at the moment so I'll setup to test them off the car. No flickering (not that I noticed) when they are working though. I must admit that the one thing I don't like about the kit are the connections into the bulb holder do seem a bit exposed. But as the headlamp shell is plastic I didn't worry too much - perhaps it's arcing to the sidelight bulb holder or something at startup, 2300v could jump quite an air gap. Maybe I'll try a refit with better insulation. Still I do like the idea of using the relay harness to reduce stress on the LSM. I'm very aware that several r75 fires have started in the LSM area.

That's because there aren't any.
The lighting is managed completely by the electronics in the LSM. Maybe that's actually why the HIDs are affecting the engine? Maybe the LSM is compromised by the HIDs and it complains to the ECU?
I'm just guessing, but knowing how delicate these cars are electrically, maybe it needs a discussion. RickSta will know.

TC

That's why I was going to change it to a relay harness, I guess the LSM will need to see some load to prevent bulb failure warnings, but how much? I do have trouble believing it would have to as much as the normal bulb would load it. I faintly recall someone on the forum testing various sized loads to find what was the smallest current that it must draw to prevent a failure warning. But I can't remember who it was, or what value would be required. Maybe I should test it myself and see?

Funny thing is that there's no sign of a problem unless the engine is running already. With the engine off there's no obvious battery drain or dimming lights when the h/lamps are switched from sidelights.

When I get some time I'll do some experiments (might be next year then!), until then I'll have to stick with the halogens throughout the winter :(.

You don't need a relay - you need a decent quality ballast.

I had this happen to me twice, once it was a faulty ballast and the second time it was a faulty burner. Just replace the lot for a decent HID kit and you'll be ok.

Any recommendations? Other than price, what makes you think the HID kit in use isn't decent quality?

When I have time I'll try and narrow down which component (or ballast and bulb combination) is causing the trouble.

Again, any reccommendations for a better quality kit?

I have 2 pair of known working ballasts if you want them :shrug: https://i.imgur.com/YdJebuUl.jpg or
https://i.imgur.com/hQ3i8Psl.jpg

Because cheap HID ballasts do this - I had the same problem and found that out, new ones swapped it.

Just going for not the cheapest would probably do it but I would recommend FastBright F3 ballasts from AliExpress