So when I turn on my switch for my lights, the headlights come on just fine, but the parking lights take a minute or two to catch up. This happens also if I just put on the switch for the parking lights without the headlights (2 part switch). Once they do come on, they will go on and off just fine. This only happens when I first put them on. It is like it has some sort of delay timer, but I don[t think it should. Would the relay that operates all these lights be screwing up? I thought a wierd thought that maybe they turn on after the engine has a chance to warm and the truck is telling me it is OK to go. I know that is not how it works, but I can't figure out the delay between the headlights and parking lights. Thanks.

missile150's Sig:

Recently purchased 1993 GMC 1 ton C3500 Sierra SLE Dually with a 6.5l TD and 100k miles. All stock (for now).

man you sure do have some weird problems with the truck no wonder the other guy was selling it that doesnt sound normal to me at all but im not too familiar with the 93 dashes i stay around the 95 and up style dashes. i know what your headlight switch looks like but i dont see what your explaining to be as normal. normally the running lights are on whenever the truck is running, until you turn the headlights on, and then the headlights overrun them.

tltruckparts's Sig:

1995 Chevy K2500, 1993 Cummins 12 valve Turbo Diesel IC, Getrag 5 speed with southbend clutch, NP205 Transfercase, SAS w/ GM Dana 60 front, Corporate 14 1 ton rear with disc brake conversion on 35's. 1/8" timing bump, upgraded pump with 3200 spring, SDX 5x14 injectors, HX40 Turbo, M&H M3 Fuel Pin, airdog II 165, Autometer Ultra-Lite EGT, Boost, and Fuel Pressure

The only other problem with the truck was the vss, and that turned out to be an easy fix. This lighting one, though, may be a little trickier. But that is what I get for buying an older vehicle during the day. Anyway, the only reference I saw was to the "DLR" or daytime running light relay. But this truck does not have any daytime running lights, and the electrical drawing actually shows the wiring going to it and then the parking lights. Now I need to find the relay and knock some sense into it, if that is what is acting up.

make sure you test it before you go waste money on a new relay. its pretty easy to test a relay

Thanks for the advice. I just have to figure out if it is straight off of the 12vdc battery voltage or off of whatever voltage the ecm puts out.