Headlights and blinker problems. Again!!

[82sbshortbed]

Don't know why my squares always have a headlight problem. I fixed the 82 shortbed problem with all new lights and new headlights switch. I think we'll see. Lol

Now the 84 longbed low beams work fine. Top two light up fine. I hit brights and no lights work. Wtf? All blinkers work until I turn on the headlights. Then the driver's side don't work. Passenger side works. Wtf?

Anybody know what is wrong? Where I should look first? It's just my luck. I'd appreciate it if I could get plan on what to test. I hate wiring. Lol

 

[DoubleDingo]

I hate wiring too. I would suggest cleaning every connection, including grounds.

 

[Doppleganger]

I guess where I would start is is there 12V when they are "on" and what are the grounds like? I dont mind wiring when its new but hunting down shorts or loose connections is purgatory.

 

[DoubleDingo]

I say that, because I was having issues with mine last year. It took me cleaning everything, which helped, but I did have to change the turn signal switch to get everything working properly.

 

[rusted nuts]

Don't know why my squares always have a headlight problem. I fixed the 82 shortbed problem with all new lights and new headlights switch. I think we'll see. Lol

Now the 84 longbed low beams work fine. Top two light up fine. I hit brights and no lights work. Wtf? All blinkers work until I turn on the headlights. Then the driver's side don't work. Passenger side works. Wtf?

Anybody know what is wrong? Where I should look first? It's just my luck. I'd appreciate it if I could get plan on what to test. I hate wiring. Lol

Bad grounds

 

[82sbshortbed]

Grounds is the first thing I'll check but that had nothing to do with the 82 because I cleanedbthem and the problem was still there. Then I cleaned up all connections and didn't help. It was the switch but I didn't hurt to clean it up. Just hate I'm gonna have to do it twice. Lol

 

[SirRobyn0]

So obviously grounds are not always the problem. But I've done my share of electrical troubleshooting on 40+ year old vehicles and it's just impossible to trace down an electrical problem if there is a bad ground. You'll spend hours and hours chasing your tail, and spending money on things you didn't need. So to me when I jump into a problem like this, yup I check and clean all the grounds first because without good grounds the rest of the system is worthless. From there I work backwards and check the sockets next.

Comments like "I hate wiring too" and "hunting down shorts or loose connections is purgatory." is pretty bang on, IMO.

 

[WP29P4A]

First thing I do when trouble shooting electrical is to use a test light to poke around and figure out where I have voltage and where I don't. Is there voltage at the headlight plugs? Then I get out my long test leads and jump from the negative battery terminal to the ground location closest to the problem area. At this point I am looking for patterns, does the issue only effect one side of the truck? Is it only the front or the back. Figuring out patterns lets you know where to look.

I use this method because I don't want to have to check EVERY connection to find the problem. When randomly checking connections for a problem it is too easy to overlook something. When you use test leads, it's real obvious when you find the problem, because stuff starts to work, the second you touch the test lead to the circuit you are working on.

 

[82sbshortbed]

I noticed when I turn lights on the green indicator light in the dash lights up. Don't even have the turn signal on. Turn off light green dash light goes out. The passenger side never turns on solid. It blinks like it should when lights are on and signal is on. Turn signal off it stops just like it should. Don't know if that helps at all.

 

[ReefkoiC10]

Bad grounds usually

 

[WP29P4A]

The first location I would check is the headlight grounds on the radiator support, second is the hi-low switch. Also to get more results for time spent, don't waste time cleaning grounds, TEST them. Use a probe/test light to test the ground, to determine IF it is the problem. Random cleaning and tightening is faith based, checking and verifying voltage and grounds at the headlight plugs with the test light, is fact based.
When you use a probe/test light to check for voltage or grounds, check the end of the wire as well as the connector crimped onto the end of the wire, if you get the same results, your good. If you get voltage on the wire but not the connector, that connection needs to be cut off and replaced.

 

[82sbshortbed]

Good tips, thanks

 

[89Suburban]

Good tips, thanks

U can do it!

 

[WP29P4A]

"I noticed when I turn lights on the green indicator light in the dash lights up. Don't even have the turn signal on. Turn off light green dash light goes out. The passenger side never turns on solid. It blinks like it should when lights are on and signal is on. Turn signal off it stops just like it should. Don't know if that helps at all."

That would lead me to believe the problem in on the left side, and one circuit is back feeding onto the other in search of a ground. Verify the ground to the headlight switch, (above e-brake) and then the driver side ground to the front signal and side marker light. Then check ground on driver side headlights.

When I say "check ground" I mean, run a test wire from the negative battery terminal to the ground location you are testing, alligator clips on the ends are really helpful. (connect to the wire or connector on end of ground wire, DO NOT CONNECT TO THE BOLT OR SHEET METAL NEAR BOLT) If this corrects the problem, you have verified the bad ground, instead of guessing and hoping. Now you can repair the verified problem.

This process bypasses all the ground straps and frame/sheet metal between the battery and the device you are trying to fix, letting you test the whole ground system at one time, in seconds.

 

[82sbshortbed]

"I noticed when I turn lights on the green indicator light in the dash lights up. Don't even have the turn signal on. Turn off light green dash light goes out. The passenger side never turns on solid. It blinks like it should when lights are on and signal is on. Turn signal off it stops just like it should. Don't know if that helps at all."

That would lead me to believe the problem in on the left side, and one circuit is back feeding onto the other in search of a ground. Verify the ground to the headlight switch, (above e-brake) and then the driver side ground to the front signal and side marker light. Then check ground on driver side headlights.

When I say "check ground" I mean, run a test wire from the negative battery terminal to the ground location you are testing, alligator clips on the ends are really helpful. (connect to the wire or connector on end of ground wire, DO NOT CONNECT TO THE BOLT OR SHEET METAL NEAR BOLT) If this corrects the problem, you have verified the bad ground, instead of guessing and hoping. Now you can repair the verified problem.

This process bypasses all the ground straps and frame/sheet metal between the battery and the device you are trying to fix, letting you test the whole ground system at one time, in seconds.

Thanks for the good information. I'll do this test this week.