I got my 6K Hid bulbs in today.. Threw my crap back in.. Was driving home and when I flipped the lights on (they are behind relays getting power directly from the battery, headlight switch just triggers the relay) my speedo went from 40 to 20, abs light came on then all went off in about 2 seconds together... Was weird.. ABS works fine.. Anyone ever have unexplained things like this? Figure its a fluke or something touched something.. I dunno.. First time I ever saw it and it made no change to the engine running..

Even with the relays, with a sudden current draw your PCM is going to detect a low current situation until the alternator kicks in the juice to keep things above par. If you are going to use them alot, you may want to find room for yet a third battery out of the loop on an isolator and run the lights off of IT.

Yep power fluctuation and surge. Storm you know how well computers like power fluctuations and surge.

Wow.. I'm stumped.. I never had this problem previously with my BAC Hid Kit in my headlights.. I'm just running a single HID filament in the headlight housing.. I just happen to switch from 8k to 6k bulbs due to me breaking the 8k's on accident.. I'll have to bust out the load charts because honestly I don't see these HIDs drawing enough current to drop my batteries and cause a power flux.. I could understand if I was running like 4-5 6" Round HID offroad lights or something..

Before I switched to the 6k bulbs I had my hids in for a month and never experienced this.. Odd

Just checked my papers.. It's only pulling 35watt's opposed to 55watt on halogen's.. Hmmm

Put an AMP probe on them and turn them on to see what you are really pulling when they first light. These bulbs may not be as efficient as the 8K bulbs or maybe on of the bulbs is defective.

Little green men did it thro a code.

When you installed the relays, did you put a clamping diode across the relay coils? You can get huge voltage spikes from Di/Dt. The diodes will clamp
these voltage spikes. If you neem more explanation, e-mail me and I'll be glad
to make a schematic and send to you. I agree with you, it isn't the battery
voltage dropping that is causing the problem......not with the cranking amps that are available in that truck!!!

I was operating on the assumption that you were ADDING more lights... Oh well, guess I better learn to read back more...LOL
I still think it is a surge, and Bob may be onto something there.

What about using a 1 farad cap in there to prevent the sudden surge? Would that help out. I know it does for heavy bass subs in the audio side.

did you route the wires anywhere near your abs wiring or sensors? if so try rerouting your wires or shielding them with aluminum foil or tape. you truck is multiplexed with the pcm and abs module to get your speed signal.

Passenger ballast is mounted just past the battery against the fender.. Wiring is routed along fender beside battery to the headlight..

Drivers side ballast is bolted to (dont laugh) the plastic cover that covers the battery and PCM infront of the Headlight, wiring is routed direct..

Like I said.. Never had this problem with the 8K bulbs.. Just now put the 6K back in.. I drove today and no issues arised..