I had a discussion with a supplier of mine this morning. He's an electronics designer and the builder of the OBS Fuel Pump Controller that we will be releasing with our complete OBS fuel system kit. He's done a bunch of work with HIDs in the motorcycle environment and is well versed in their shortcomings.
First off, he basically bet me money that if we were using Bosch OE level ballasts in these trucks, none of these issues would exist. Even though the aftermarket ballasts are in metal cases, he said that the EMI and RFI from the HID ballast (particularly during startup) is pretty extreme. It's his contention that none of the aftermarket ballasts have anywhere near the level of EMI/RFI protection that the OE Bosch pieces do, which he feels is the ultimate source of our woes.
Next, he said that EMI and RFI degrade very quickly over distance. He feels that even a terribly insulated ballast would only be able to affect surrounding devices that are within "inches" of the ballast case. When I mentioned that the PCM and Chip being discussed here are generally in the neighborhood of 4' away from the ballasts (assuming most are installing them near the drivers headlight), he was very skeptical that the problem was actually EMI/RFI (at least "through the air").
I then asked if it was possible for the ballasts to put enough "noise" on the wiring to affect electronics that may be connected through a nearby junction point. He indicated that the ballasts "should" have protection to prevent this (but again referenced the quality of a Bosch OE unit vs "cheap" aftermarket units) and also indicated that the factory electronics in the vehicle should have power input side filtering due to the "nasty" nature of the car electrical system. Whether the filtering in the stock Ford electronics is enough is unknown without actual testing. When I mentioned the situation with my 6.0L truck, and the fact that it cleared up when all of the wiring was moved to the battery on the opposite side of the vehicle, he seemed to think that reinforced the theory that the "noise" that is causing the problems is actually on the wiring and not "over the air".
I asked about possible other solutions and had to dismiss his first response of "install Bosch ballasts" (I think he's got a problem with aftermarket HID ballasts...but I'm just guessing). I asked if something like additional grounds on the ballast case would make a difference, he said "not likely". I then asked about using a ferrite bead on the power wires for the ballasts and he thought that might be worth trying. He said that if you only have one, and it's big enough (he recommended the ones that are 1" or longer), to run both the power and ground wires through it, or to "double wrap" the power wire through it. This is just a guess...but he felt it was worth a try.
I don't currently have a truck available that is having a problem. If someone with a problem truck with HIDs is reading and willing, let's try some things and see if we can come up with a good solution.
