I bought a 99 f350, that already had HID's in it, i found out i was running the wrong batters (weren't 800 cold crank) I just had to replace the alternator. Ever since the new alternator when i turn on my headlights my truck shuts off. IT fried my IDM and i just put a new IDM and 2 new batteries in it today. Thinking i had fixed the problem i drove around no issues, finally i was leaving someones house and turned on my lights, and truck shuts off!!! It restarts but now im trowing a code!!!! im guessing the HIDs are wired wrong and that's why its shutting down the truck but OEM IDM from ford is 1300$!!!!! brand new one installed today, any help would be great as i am tapped out of $$$

 

Moved from 80-86

 

You seem to have in narrowed down to the lights. Why not pull the power calbe off and check location, grounds, etc... Maybe just rewire it ?? Are they wired directly to the original light wires, or do you have a relay system to turn them on ?

 

i pulled the HID lights out, there is a wire harness that connects the hid lights to the stock wire harness. i reconnected stock bulbs and everything is fine (such as the truck runs great and doesnt die when the lights come on) however every once in a while, while im driving the "service engine light" comes on, idk why though

 

Take it to an auto parts store and borrow a code reader to pull the codes.

 

I would almost believe the HID system is generating interference the computer is picking up.
It may be stopping the computer's normal processing.
Unless you have a way to do testing I would not go back the the HID system.