1999 Chevy Silverado Lights Problem

[SwamperRider]

Ok, I have a 1999 Chevy Silverado Z71. Just recently (like 3 days ago i think) I was driving my truck home at night and all of a sudden my headlights shut off (or went VERY dim, not to sure but I know I couldn't see) and my dash lights started coming on but not blinking or anything (blinkers lights, abs, check engine, brake...) but they were all dim like they wasnt suppose to be on but were. When I pulled over into a horseshoe driveway I put it in park and my truck was on a slant and rolled forward till the park gear in transmission stopped it and the headlights came back on and the lights on the dash went off. Well right when I put it in drive and let go the brakes the lights went very dim again and the lights on the dash came back on very dim also. Well next thing I did I went under the hood to the fuse box there and the "hdlp" (headlamp I'm guessing?) relay was vibrating and making noise, Well I took it out and it quit buzzing and I switch the relays with a different relay and my headlights came on and when I put it in drive to go again it did the same thing so I started driving down the road again and it looked like everytime I hit a bump or something the headlights would get brighter like they are flashing every once in a while. I got home and I put my truck in reverse and held the brake and pushed the gas as if I was going to power brake it in reverse and the lights came back on but I didnt let go the brakes but did let go the gas but as soon as I let go the brakes the lights went back dim and the lights on the dash came back on. I'm not to sure what's wrong with my truck but it sure is aggravating. If you or anyone you know knows what's wrong with my truck I will greatly appreciate it very much!! Thanks and god bless!

 

-Kenneth.

[98 Z71 SLT]

You have a loose ground

 

Trace all your ground wires, especially the grounds under the driver door area (on the frame)

[Stevens03]

X2 on the ground... I'd start there too.

[SwamperRider]

Alright I'll try all that tomorrow and see what happens. Also my security lights flashes alot...I have a system in my truck and when i turn it loud the security comes on and my radio shuts off like its pullin to much power but I had the system in my other truck (same as this one) and the security light NEVER came on at all.

 

But I will let yall know what happens when I check the grounds and stuff. We tried today but was looking under dash and stuff for grounds and broken wires. But no luck.

[jblakeney]

Ground, PCM, battery, or alternator....

 

Start at the ground thou.

 

Jbo

[SwamperRider]

Ok, I checked the grounds on the frame under the driver side and they are good and tight. When I tried starting my truck it would start then kill right after and it did that a few times then it cranked up.

 

I'm no mechanic and I don't know where everything is (PCM and other things I read online to check)...I just think it's weird how when I put it in reverse and give it the gas for a sec and let go everything works perfect but as soon as i let go the brakes it goes back to what it been doing. I got a lil video of the dash b4 I give it the gas in reverse and after I let go the brakes but I don't know how to get it off my cell phone onto my computer.

[JRLZ71]

. I got a lil video of the dash b4 I give it the gas in reverse and after I let go the brakes but I don't know how to get it off my cell phone onto my computer.

Send it to your email, upload it to photobucket, and then post it on here.

[jblakeney]

Ok, I checked the grounds on the frame under the driver side and they are good and tight. When I tried starting my truck it would start then kill right after and it did that a few times then it cranked up.

 

I'm no mechanic and I don't know where everything is (PCM and other things I read online to check)...I just think it's weird how when I put it in reverse and give it the gas for a sec and let go everything works perfect but as soon as i let go the brakes it goes back to what it been doing. I got a lil video of the dash b4 I give it the gas in reverse and after I let go the brakes but I don't know how to get it off my cell phone onto my computer.

 

If increasing rpms help take the alternator off and have it bench tested... . And the battery tested out of the truck..

 

Jbo

[jblakeney]

Ok, I checked the grounds on the frame under the driver side and they are good and tight. When I tried starting my truck it would start then kill right after and it did that a few times then it cranked up.

 

I'm no mechanic and I don't know where everything is (PCM and other things I read online to check)...I just think it's weird how when I put it in reverse and give it the gas for a sec and let go everything works perfect but as soon as i let go the brakes it goes back to what it been doing. I got a lil video of the dash b4 I give it the gas in reverse and after I let go the brakes but I don't know how to get it off my cell phone onto my computer.

 

If increasing rpms help take the alternator off and have it bench tested... . And the battery tested out of the truck..

 

Jbo

[SwamperRider]

Its not really because the higher rpms. Because I can keep it in any other gear besides reverse and the lights dont fix them selves...only in reverse it does it but the lights stay fixed as long as im holding the brakes. I just got the video off my iphone...had to download all kinda crap. But I finally got it. I'll post it when I get it uploaded to photobucket.

 

Thanks for all the help so far. But the problems not fixed yet...

[SwamperRider]

Sry I sound pretty goofy haha

 

[[email protected]]

That's definitely a ground. Probably some where near the brake lights on the back. I'd check all the wires and grounds for the taillights on the back of the truck, including the circuit board on the rear frame, under the bed.

[SwamperRider]

I will check all the wires and grounds back there. We looked over all that yesterday but didnt look like nothing was undone or coroded or anything so we didnt really fool with it. But will unplug and clean connections and look threw all the wires. I'll get another video of wat the headlights do when u in reverse and power brake it. Hopefully we can find out the problem. Just makes me want to burn it to the ground when things like this go wrong.

 

Will keep the thread updated as I do things.

[SwamperRider]

Ok, my uncle is a mechanic at a lil shop down here and when I told him what my truck was doing he said its most likely the multi-function switch? Do you guys agree with him on that? I'm just tryin to see if thats really the problem before I go out and buy a $100 piece that I don't need.

[[email protected]]

Ok, my uncle is a mechanic at a lil shop down here and when I told him what my truck was doing he said its most likely the multi-function switch? Do you guys agree with him on that? I'm just tryin to see if thats really the problem before I go out and buy a $100 piece that I don't need.

If it's your uncle and you trust him, let him figure it out. But, I really doubt a multifunction switch could have anything to do with that. I know every electrical part and the wiring on the truck work, and I couldn't imagine a multifunction switch doing anything like that. There's only a couple multifunction switches on that truck like brake, turn signal, headlight, 4wd, and wipers.