Hazard/Turn signal issue has me stumped. Some success.

[Countryoutlaw7]

Hello, I have a 1997 XLT 4x4 with the 4.0. I use this truck daily for my mail truck, until I get a new one then it will be my woods truck. For my profession hazards and turn signals are really important. So here is my issue.

99% of the time when I use my hazards or turn signals they work fine but my Hi Beams will also flash. It’s always both Hi Beams not just one. On the instrument panel, regardless of which turn signal I use, both of them light up.

If I mess with fuses, relays, or unhook the battery when I turn the truck back on they work fine the first few times then go right back to flashing my brights.

I’ve tried fixing the problem before coming here. First thing I did was check all the grounds, they’re all factory but seem to be in good shape no rust or corrosion and they’re tight.
Then I replaced the turn signal switch with one from a junk yard, it seemed to be in good shape but I’m thinking of buying a new one just to be sure unless I get an answer from here. The relay seems to be functioning properly and I don’t have any blown fuses. The truck needs a new computer but I’m fairly certain that isn’t the issue here.
Help! If anyone has any suggestions. I do have plans to make some upgrades to my wiring later on, as I haven’t had this truck long and the previous owner did not take care of it properly those upgrades are on the back burner.

 

[19Walt93]

That sounds like a poor ground to me. Did you take all the grounds apart to check them or just look? Years ago we had a 4 day old Explorer towed in with a no start. It turned out that the ground for the EEC relay or PCM had .8 ohms of resistance and only .5 ohms was allowed. The tech removed the screw, scratched the paint off and put it back together.

 

[19Walt93]

The core support would be a good place to start checking the grounds.

 

[Uncle Gump]

Grounds are a good possibility... but with the high beams flashing too... sounds like the multifunction switch may have and intermittent issue causing the problem. Also with the amount of time you run the hazards... heat will build at the connector. I would take a serious look at the connections and look for heat issues.

 

[Countryoutlaw7]

I took apart all the grounds I could find. Cleaned them up and put them back tight with no luck. I don’t have a meter to test them but once I get a new one I will. I’m also going to pick up a new switch next week I’ll post back with my findings.

 

[Countryoutlaw7]

I took apart all the grounds I could find. Cleaned them up and put them back tight with no luck. I don’t have a meter to test them but once I get a new one I will. I’m also going to pick up a new switch next week I’ll post back with my findings.

 

[Countryoutlaw7]

So it’s not the grounds. All of my grounds are good I took a multimeter and checked the continuity and they all read good. I’ll swap the switch when my new one comes in and update.

 

[ratdude747]

So it’s not the grounds. All of my grounds are good I took a multimeter and checked the continuity and they all read good. I’ll swap the switch when my new one comes in and update.

Tested under load? Continuity won't tell you if a ground is bad or not (unless it's completely blown open)... might be good enough for the puny load of the meter, but not good enough for your electrical system. The best way to test grounds like that is to put it under load and check for a voltage drop between the ends.

 

[franklin2]

I am assuming your little blue high beam light in the dash also blinks with the hazards?

The way to put the rest the ground issue is to find the ground wire coming off one of the front turns signal sockets, scrape the insulation away in one spot, and clip a temporary wire to the ground wire and run the other end over and touch it to the battery negative. I would fire up the hazards, and while watching the high beams blinking, touch the wire to the negative battery post and see if the high beams go out.

 

[Countryoutlaw7]

It actually doesn’t the only time the blue hi beam light would come on was if you actually turned them on. I’ve recently “fixed” the issue kind of on accident. I had my instrument cluster apart replacing some blown bulbs and once it was out that’s when I found out the instrument cluster has been replaced with one from a junk yard. The board on the back that powers the lights and gauges had some corrosion dust all over it and looked to be flaking. I replaced all the bulbs but once I plugged it all in and put it back together the dash turn signal lights and the hi beam lights no longer worked. However, the turn signal, hazards, and hi beams work as intended now. Looking at the cluster it looks like it’s off an older truck but I’m not 100% sure. I am also having an issue where my coolant temp gauge doesn’t work correctly and I’m guessing this issue is related. When I ground the wire out it tops out but after replacing the sensor and double checking the connection it’s still not reading properly, it starts below the cold line then warms up to the cold line but doesn’t go past it. I also found the OD wire cut clean and a few other issues in the dash I was planning on picking up a white faced instrument cluster and doing the resistor swap to make it work so I’ll update if that clears up my problems. It could also be the wiring harness the person who took it off before managed to break the clips and I didn’t have time to fix it properly this time so I’ll likely replace that just need to pick up some more solder and heat shrink.

 

[Countryoutlaw7]

Tested under load? Continuity won't tell you if a ground is bad or not (unless it's completely blown open)... might be good enough for the puny load of the meter, but not good enough for your electrical system. The best way to test grounds like that is to put it under load and check for a voltage drop between the ends.

I did not test it under load I’m new to the electrical problem scene so I’m learning how to use a multimeter for more than just checking outlets in the house. But, I had some success after replacing bulbs and seeing the poor shape of the circuit board on the back of the instrument panel.

 

[Countryoutlaw7]

I am assuming your little blue high beam light in the dash also blinks with the hazards?

The way to put the rest the ground issue is to find the ground wire coming off one of the front turns signal sockets, scrape the insulation away in one spot, and clip a temporary wire to the ground wire and run the other end over and touch it to the battery negative. I would fire up the hazards, and while watching the high beams blinking, touch the wire to the negative battery post and see if the high beams go out.

The blue light didn’t blink with it. The blue light only would come on if I had my brights on. The left turn signal would make both lights on the dash light up like the hazards but the right did not. I had some success when I took apart the instrument cluster to replace bulbs but the issues not 100% resolved.

 

[franklin2]

The little blue light is tied directly to the high beam wiring. But considering what you found out with the cluster, I guess that explains the blue light not coming on.

Troubleshooting a problem that normally happens on an otherwise stock truck is one thing; Doing the same on a truck that someone has messed with the wiring is a whole different ballgame and can be difficult to get right. Just be patient and remmeber you have time to mess with it and figure it out, where a garage doesn't and would want to get another harness and replace it.

If you think the cluster is causing some problems, for troubleshooting purposes I would unplug it and then see how the truck's wiring functions react to that. I think I am correct is saying for the exterior lighting, the cluster is not really needed except for the driver's indicators and they are not needed for normal function of the lighting.

 

[Countryoutlaw7]

The little blue light is tied directly to the high beam wiring. But considering what you found out with the cluster, I guess that explains the blue light not coming on.

Troubleshooting a problem that normally happens on an otherwise stock truck is one thing; Doing the same on a truck that someone has messed with the wiring is a whole different ballgame and can be difficult to get right. Just be patient and remmeber you have time to mess with it and figure it out, where a garage doesn't and would want to get another harness and replace it.

If you think the cluster is causing some problems, for troubleshooting purposes I would unplug it and then see how the truck's wiring functions react to that. I think I am correct is saying for the exterior lighting, the cluster is not really needed except for the driver's indicators and they are not needed for normal function of the lighting.

I’m actually ahead of you on that. The trucks lighting performed normal unhooked from the instrument cluster. The only thing I can’t vouch for is the hi beams flashing because I did hook the dash up after installing the new bulbs, which I should mention they’re LED not that I think that’s the cause of the new situation. But with the cluster unhooked the lights all worked as they were supposed to. When I hooked the cluster back up I noticed some of the circuit board seemed flaked and chipped so I’m guessing that’s the cause of a few of my dash lights not working. I noticed the fuel cap light is also not coming on. I was going to replace the harnesses because the clips for them were broken by the last guy as well. They seem to hold fine but I’d like to replace them so I don’t have any issues later on. The trucks a fun project I’m hoping to replace it with something else for a mail truck and keep it for a woods truck but I still am enjoying the repair process. The closest junkyard to me is over an hour away so I’ll have to wait until I get a day off and make a trip. I’ll update with my results also I need to repair my OD switch the guy cut it somehow before. But the dash lights are looking good.