Converted my 01' headlights to a quad light setup with homemade heavy duty harnesses and relays as per the tech articles on this site. Had no problems until I then changed the 9006 low beams to HID's (with ballasts). Don't think that the HID's are necessarily the problem because I've been running the quad setup for a year w/o any problems. The conversion was a simple bulb swap and wire the power and ground for the ballasts to the same power and ground as the 9006's. Now, when I turn on the headlights, the engine will stumble and stall (or come close) and throw the service light and glow plug lights. The engine doesn't do this when the marker lights come on, it only happens when headlights are lit. I've gone through and checked the harness and made sure it wasn't a grounding issue, changed grounding location to an isolated spot solely for the lights. Was thinking it may be a bad relay but not so sure I would get these kind of symptoms. Any thoughts?

FWIW I got the HID's from Xenonlink, which others on this site have used w/o issue. I love the lights but the stalling is a pain, plus I don't want to screw up the computer if I'm getting some type of electrical surge or backflow.

 

Yes, I had that problem with my XenonLink kit, too. I still get it occasionally. When I first put mine in, I didn't ground one of the ballasts and it was very bad. After I grounded the case it got much better.

Here's what I think happens: When these first start, the ballasts put out something like 20kV to get the arc started in the bulbs. Then it drops to a couple kV because once the arc starts, it takes much less to maintain it (that's why there's a flash at start up). I believe that start burst puts out a lot of RF noise, which interrupts the computer briefly. I know the computer puts out some trash in the VHF range because I have a radio in that range and can hear it/see it on the signal meter. I have been thinking about ways to quiet them down, but haven't done a whole lot yet since mine isn't that bad any more. I will try a couple tricks and see if any of them work and let you know.

 

Since you see the glow plug and service lights it sounds as if system voltage dropped as the increased load from the new headlights was seen.

A poor connection or ground would also cause this voltage drop so I'd check those first. If everything checks out, you may have to power the headlight ballasts directly from the battery to prevent this voltage drop. Just use a relay that is actuated from the stock headlight wiring so that the headlights operate from the normal switch.

Lou Braun

 

Izzy, how did you ground the cases? The mounting brackets that came with mine are aluminum (didn't realize that til I mounted them directly to the body and tested them for ground). No luck with that, though the buzzing from the ballasts on start up is reduced.
Lou, I am already driving the headlights directly from the battery (with proper relays and fuse blocks, #14 gauge wire). I have a digital volt meter in the truck, and I thought exactly what you said. However, I only see maybe a drop of 0.1 volt when the lights are switched on.
I'm not an electrical genius, but do you guys think I need to place a diode in each trigger wire to prevent any backfeeding? Am I correct in thinking that if the relays are good I shouldn't have to do this. The engine would do the same thing when I switched to low beams from the high beams. I did the diode trick to keep the lows on with the highs and that eliminated the problem in that instance. Going to drop a note to Xenonlink and see what they say. I'll keep you guys posted of my results.

 

Still stalling, any other ideas??

 

First of all, the load is *decreased* because HIDs draw much less current than incandescents (just like florescent bulbs do). It is going to be a noise thing -- trick will be to figure out exactly the right fix. It won't be fun, but I'll see what I can come up with. I'm thinking some ferrite on the power leads to the ballasts may do it. I'll pick up a couple and see if that improves it.

To answer your question about the grounding thing, I mounted one of them on non-grounded plastic (battery box), so when I moved it to the metal fender, it was grounded and cleaned up a lot of my issues. If the ferrite works (and there is good chance that it will), I'll send Xenonlink an email and tell them.

 

Thanks Izzy, I've already moved them to the radiator support bolts (which showed as a good ground when I tested them) but the brackets are aluminum. Was going to try and solder a ground wire directly to the case but figured I might have a probloem if a warranty issue arose. Going to have to make a Faraday box I guess

 

Before spending the effort to build a box try maybe wrapping them with grounded foil to see if it accomplishes what you are looking for.

As to introducing a diode anywhere in the circuits, I would presume that would develop a voltage drop, so once again I'd make a temporary test first....

 

As to the primary problem, there is after all with a 2001 vehicle some possibility that there's absolutely nothing wrong with the lights. When you turn them on there is obviously an increased load on the battery/alternator. Just because your voltage didn't drop doesn't mean your current didn't drop.

Find something like maybe a 12 volt winch and run it instead of your lights to see if that load causes the idle to drop. FWIW I've always found the hardest problem to find is the one that doesn't exist.....

 

Actually the best load would be a battery tester, where you can set the rheostat for however many amps you want to draw. I think a small one, maybe 50 to 100 amps, is pretty cheap, like $30 maybe at Harbor Freight.

 

Don't forget to check the rest of your grounds also. I've had the same problem on a 96 450 gas motor at work (all stock) that was a loose ground under the dash near the fuse panel.

 

I'm running HID's in the fogs and headlights with no special grounding and no interference. I don't have any extra harnesses either.

Since the problem seems to be related to the increased load on the engine/alternator can we bypass the harness to see if it is a wiring issue with the harness or a load issue with the lights? If using the original wiring eliminates the problem then there is a power/ground issue that is causing interference with the electronics. If it still does it, then it could be an alternator/battery issue, or a power/ground somewhere else in the charging circuit. Even if the truck seems to start ok, a faulty cell in one of the batteries could show itself during a power spike.

 

Bones, I was just kidding about the box but your idea about grounded foil did cross my mind. Regarding overall voltage drop, I've got two big-as-you-can-get Optima yellow tops about 6 months old. Also have a 4 light KC bar up front running 4- 7" 300k candlepower lights. No problems when I ignite those bad boys... No stall, etc.
The harnesses I made myself with Bosch relays and #14 wire, fuse blocks, etc. Each beam (4 total) has its own relay and each headlight is wired to that respective side battery. I've redone the harnesses and grounds specifically to cure this and no luck.
Only thing that is bugging me is my alternator. Got to run down to A-zone and see if it's up to par. Haven't had any starting problems but don't know if it's original (truck has 112K on her). I would think I would notice a problem when lighting all those KC's, but they never give me any grief.

 

And Chris, I'm going hunting bad grounds again today. Can't hurt to look...

 

Guys, the HIDS are *NOT* an increased load!! They draw LESS current than standard headlights. That isn't the problem. The problem is the starting voltage for the bulbs creating a massive noise spike interfering with the PCM. You can hear it with a radio (not the truck's radio obviously) nearby.