2nd Gen Non-Engine/Transmission Another Headlight Switch Burnt

[EBramwell]

HELP! I had my headlight switch burn out the other night and by the time I got home I had nothing but headlights. No dash lights, no running lights, no hazards, nothing.

I replaced the headlight switch and wiring harness that connects to the switch, and also put in a headlight wiring harness with relays connected to the batteries to take some of the load off the switch.

Well after getting everything wired I tested it.

1. I now have lights working on everything but the bed.

2. Also if I turn the headlights on the trailer brake controller light turns on?

3. Tested it at night and found if I press the brake pedal the bed lights come on very dimly???

4. If I turn the hazards on they start blinking the radio and, blink really fast outside and then slow way, way down.

I bought another new light switch and tried that and, the same thing. Disconnected the trailer break controller, no change.

Checked all fuses and relays and all are good.



Help... I have no tail lights no brake lights, any suggestions?

 

[LandShark]

Start by double checking every thing you changed. Be sure the grounds are clean and tight. Then pull the new relays for the headlights and see if everything goes back to normal (except the headlights, of course).

Did you make your own headlight relay harness?

 

[EBramwell]

Thanks LandShark, I tried your suggestion to no avail. I bought the harness from LMC.
I noticed that when I stick a test light on each wire on the back of the new switch I get a light on all wires except for two wires, the light blue and the blue black are dead? I have know idea what these two wires go to?
I also pulled the hazard fuse under the hood, the bed lights came on, dimly but they came on. I checked the ground strap on the bed and looked as best as I could for any cut wires but, everything looked ok.
I noticed also that when I first turn the blinker on it always blinks the radio at least once.
Everything was working fine until the switch melted, now... well now I don't have a clue?!?!

 

[LandShark]

The only other info I can add is that many of the circuits on our trucks are "ground switched". That's why it's so easy for things to get turned on when wiring gets messed up. You may need to spend a few hours digging into the factory service manual; their electric diagrams are quite complete.

I would also double check the LMC wiring harness to see if it was done right. Sometimes even the factory can screw up.

 

[Joe G.]

Better to remove the LMC wiring and do it yourself. As LandShark suggested use the factory service manual wiring diagrams. Your '97 may be a little bit different than our '95s, but the headlamp wiring is probably the same. If you don't have a factory service manual you can get one from Geno's Garage on CD for $35. The diagram you need is on page 8W-50-2. Install a relay in the wire between the headlamp switch and the dimmer switch. There are two wires that do that. You want the one from the head pin on the headlamp switch. The other is the "pass" switch. If you need any help with exactly how to do the wiring email me. This mod will reduce the headlamp draw from whatever it is to 0. 1 amps.

 

[AABEN]

Thanks LandShark, I tried your suggestion to no avail. I bought the harness from LMC.

I noticed that when I stick a test light on each wire on the back of the new switch I get a light on all wires except for two wires, the light blue and the blue black are dead? I have know idea what these two wires go to?

I also pulled the hazard fuse under the hood, the bed lights came on, dimly but they came on. I checked the ground strap on the bed and looked as best as I could for any cut wires but, everything looked ok.

I noticed also that when I first turn the blinker on it always blinks the radio at least once.

Everything was working fine until the switch melted, now... well now I don't have a clue?!?!

Dodge has had this even on the 01 if you ran on high beam and pulling a trailer with a lot of lights. You might try to put some on a diffrent switch or try to get a switch out of a 03. I have not had this happen on my 03 ==Good Luck ==

 

[rrl989]

I replaced my original oem 98 switch at about the 5 yr mark, replaced with the same and it's about 8 yrs now. Not to go against the crowd, but I don't think running headlights through an aftermarket relay is a good idea. Relays are more likely to fail over time.

 

[Bob Cochran]

When you have things happen weird such as lights you don't expect to come on do and dim, etc. You are getting a back feed typically on the ground side and once you fix the problem say replace blown fuse or bad wiring or such that will correct itself.

 

[Missouri Mule]

Seems like you have wires shorting out.

On my 88 ford van my mechanic's dog chewed the wirng near the tail lights. It did all type of wierd things took me an hour on the side of the road to get all the wires spliced back together.



I have a utility trailer that doesn't get used much, after sitting for a long time water gets into the light and rust the socket. When I hook it to a vehicle the trailer and truck lights are messed up because the trailer light lost its ground( uses the tail lghts or brake/turn signal connetor/wires as ground. Wire brush the socket out and I get the ground back and lights work right again.

 

[DieselDoghouse]

OK…not looking to get flamed but after 30 years working part-part-time alongside my IEEE father (microwave engineer) I have to PARTLY disagree with

rrl989. Adding relays to control your light load circuits is not a bad idea if your wiring is secure. Yes relays can fail (if they're cheap knock-offs) BUT they can be mounted to be alot more accessible to replace than the dash-embedded switch! PLUS you get to chose your rating (you couldn't too high), and I really don't think a 50 or 70 amp 5 pin ISO relay is under-rated versus the switch! Plus our dash switches are available from essentially one producer and limited distributors…its more likely you can get a comparable relay even in "East Mooseshoe"—which is where it would of course fail!.

IMHO - I would (and have) run a relay bank (you would need 2) from fused feeds from the battery and use the OEM harness to control the coils. Truth be told I even did each side separately (we got 2 batteries anyway) so if I lose power feed on one side I still have some light!! Just my 2¢

 

[EBramwell]

Well I found the culprit! There were two wires under the the flat bed in the wiring harness bundle, one was broken, the other (ground wire) was nearly broken.

Repaired everything and now it's working as it should be.

Thank you all for the support, I appreciate it.

 

[rrl989]

OK…not looking to get flamed but after 30 years working part-part-time alongside my IEEE father (microwave engineer) I have to PARTLY disagree with

rrl989. Adding relays to control your light load circuits is not a bad idea if your wiring is secure. Yes relays can fail (if they're cheap knock-offs) BUT they can be mounted to be alot more accessible to replace than the dash-embedded switch! PLUS you get to chose your rating (you couldn't too high), and I really don't think a 50 or 70 amp 5 pin ISO relay is under-rated versus the switch! Plus our dash switches are available from essentially one producer and limited distributors…its more likely you can get a comparable relay even in "East Mooseshoe"—which is where it would of course fail!.

IMHO - I would (and have) run a relay bank (you would need 2) from fused feeds from the battery and use the OEM harness to control the coils. Truth be told I even did each side separately (we got 2 batteries anyway) so if I lose power feed on one side I still have some light!! Just my 2¢

No flame, just my opinion. I work in the industry, a high end MIL Spec relay would work just fine, but I would never rely on any typical over the counter crap available for a head lamp system.

 

[KRStone]

I replaced my original oem 98 switch at about the 5 yr mark, replaced with the same and it's about 8 yrs now. Not to go against the crowd, but I don't think running headlights through an aftermarket relay is a good idea. Relays are more likely to fail over time.

Relays do fail, often... however it's much much easier to pull over the replace a $15 relay than it is to order a new switch, drive home, pull the dash bezel, unscrew the switch, unplug from the harness, then instal a new one in reverse.



I have the suvlights setup for dual headlights on my '96 (bought sport headlight housings on ebay) and love the brighter lights and the cooler dash switch.

 

[Bob Cochran]

Well I found the culprit! There were two wires under the the flat bed in the wiring harness bundle, one was broken, the other (ground wire) was nearly broken.

Repaired everything and now it's working as it should be.

Thank you all for the support, I appreciate it.

Fantastic glad to hear you have it solved.