running light problems

[chevy 9800]

Hi there i am new here and was looking up common problems for my tahoe. it is a 98 4x4 350 auto. the problem is that i keep blowing the 20 amp fuse for the running lights and it also takes out the dash lights. i didnt have any issues with this till now. we do have a brake modual for trailer breaks and that is new and never had an issue with it. i feel the issue isnt a wire i have been thinking the switch in the dash has a short in it. the reason why i think it is the switch is because the dome over ride button never worked right and the reostate seems to be tuchey sometimes. if someone had this issue before please let me know what you did to fix it.

[retorq]

You put in a new trailer brake module, started popping fuses and you don't think it's the brake module?? Did I read that right??

[chevy 9800]

i put the modual and wiring in this past summer never had an issue with it. i did disconect it from the truck and we are still haveing some issues with it. my wife told me that when she puts on her blinker that is when it blows. I will be working on it to see what the issue is it really sucks that i have to work around the air bag. i wont mess with that.

[chevy 9800]

well the problem to the running light was the headlight switch in the dash. i guess it is a common problem. i bought the new part at o reilys and put it in right away and drove around for a little bit to see if it would pop the fuse. so far there isnt a problem with it.

[chevy 9800]

ok well so the light switch didnt work like i thought. so i went and disconected the trailer brake module. the problems dont happen when the temps are warm but they do show up when the temps are cold out. if anyone has any ideas that would be great. thanks

[SunlitComet]

If I read the diagrams correctly that 20 amp feeds the diode to the relay to the low beam lamps. You probably have an internal short along the way maybe because of condensation. Use the digrams below to help identify your wiring and check the lamp sockets. You might have a bad relay if both of you low beams work as regular headlights. Unless you have factory fog lights then there is another diagram to look at.

http://www.sunlitcomet.com/images/automotive/162503933.gif


http://www.sunlitcomet.com/images/automotive/101538924.gif

[RegalCavalier]

Looking at the first diagram, it appears that the DRL relay is powered by the fuse for the gauges. It is most likely you have a bad DRL relay. Is it fuse 4 (10A) that blows? Are there other fuses that blow? Of course I'm assuming these diagrams are for your truck. At least it is something to look for.

[BLUE BEAST]

so would the headkight switch cause the drls to not work or make your head lights go on and off?

[SunlitComet]

You can pull the headlight switch out and disconnect it. If your drl system still blows then follow the diagram thruogh all the components. But it is still likely your drl relay module. When you said make your headlights go on or off are you talking about turning on your headlight switch and your low beams cycle on and off continously? What about high beams being selected? If so then I would strongly suggest you check your headlamp harnesses for high and low circuits that are probably grounding somewhere.