Problem with low-beam headlights. Need suggestions.

[billy bee]

Low beams are not functioning properly. High beams work fine if I pull on the stalk, but they do not click into high and stay there. If I want the high-beam lights to work I have to hold the stalk. I only get hi-beams and if I let go I get nothing.The backstory: I was driving home from work this weekend and using my headlights on the Pacific Coast Highway. It was foggy in spots and the low beams were working fine, I think. At least they worked fine the night before... At one point I sped up for a pass and flashed my high-beams to indicate I was coming through. (It's a narrow road in most places.) As it was getting dark, I realized the low beams were not working. Any ideas on where to start? Multi-function switch on the column?98.5 QCSB 4x4 w/ 178k...Thx,bb

[Wild and Free]

You got it, they are pretty cheap multi function switches. It is only about a 10 minute job to swap them out. I have had several die just the same as what you describe.

[billy bee]

You got it, they are pretty cheap multi function switches. It is only about a 10 minute job to swap them out. I have had several die just the same as what you describe.

Do you buy junkyard replacements or new? bb

[Wild and Free]

Do you buy junkyard replacements or new? bb

Always new with electrical stuff. Go to rockauto.com, they usually have some of the best prices and best selection.

[billy bee]

Thanks for the link to Rockauto. They do have good prices. THey show three different suppliers for the switch. Have you had any better luck with one than another?Thanks again,Bill

[Mopar1973Man]

Yeah the multi-function switch tends to fail so it best to replace that soon... Really scary to loose your headlights on a windy road... Yeah like W&F said buy new it not worth messing with used junk...

[billy bee]

OK. I'm still at this. I changed put the switch and still no lights. No, I did not buy a new one. I got a good used one. At least I think it's good. From what I hear, the switch burns out. Melting plastic. Smoke. Broken.

Both of mine look and feel fine. You can even look at the contacts and see the hi- and lo-beam contacts moving around in the assembly. They look fine.

Is there anything else that could cause this problem? I can't find a relay. Bad ground somewhere?

bb

[LiveOak]

My headlights fail periodically when switching from high to low beam or vice versa. When this happens, I rapidly cycle the stalk switch until the lights come back on and they work normal for a long time. I think it is a matter of a cheap ___ switch that gets corrosion or bad contacts. I suspect that eventually it will fail altogether but until it does, I just keep rolling on with this fix. It has worked so far of the past 5 years. :banghead:

[KOYOTE]

i had this problem id hit the highs and return to no lows, replaced the relay in the pdm under hood and never had a problem again but i have seen a many modules with burned out contacts, i got lucky with just the relay though

[billy bee]

i had this problem id hit the highs and return to no lows, replaced the relay in the pdm under hood and never had a problem again but i have seen a many modules with burned out contacts, i got lucky with just the relay though

I checked the relays and could not figure out which one was for the lights. What is the PDM? Is that the bank of fuses and relays directly behind the driver's side battery? Which relay? How is it marked? All the smaller relays are the same, so it would be easy to check with a known good one. Meanwhile I have taken the two multi-finction switches completely apart. It was pretty dirty. I cleaned all the contact surfaces. None of the contacts are burned in any way. They cleaned up beautifully. I will re-assemble it in the morning and report what I find... bb

[Mopar1973Man]

I checked the relays and could not figure out which one was for the lights. What is the PDM? Is that the bank of fuses and relays directly behind the driver's side battery? Which relay? How is it marked? All the smaller relays are the same, so it would be easy to check with a known good one.

Meanwhile I have taken the two multi-finction switches completely apart. It was pretty dirty. I cleaned all the contact surfaces. None of the contacts are burned in any way. They cleaned up beautifully. I will re-assemble it in the morning and report what I find...

bb

Get pics of it... If it works out we might have a full write up of how to save a few bucks on Multi-function switch...

[AABEAR]

Get pics of it... If it works out we might have a full write up of how to save a few bucks on Multi-function switch...

Michael I hope you can get that done.I know it would help a lot of us out. == Thanks ==

[billy bee]

Get pics of it... If it works out we might have a full write up of how to save a few bucks on Multi-function switch...

OK. Here are the pix:

The switch splits easily into two parts by removing the 5 small torx screws:

Lift the backside of the case away from the stalk assembly:

To check the hi-lo switch, focus on the small back section. Remove two smaller torx screws. I did not have the right torx bit, so I used a small screwdriver:

Pull the backing plate away to expose the hi-lo switch mechanism. You can see on the left the turn signal board is exposed and the accumulation of dirt and wear is obvious there:

While this is a really crappy picture, I wanted to show how dirty all the circuit board contacts had gotten:

Now you can see the board more clearly. I am holding an arm that actuates a rocker switch. This also has contacts on it. I cleaned them and tried to figure out what those contacts do. Using a muyltimeter to measure resistance, I discovered that this sliding arm only conducts when the stalk is pulled toward you while switching to/from hi-lo or while flashing. So, while flashing it is the conductor. It works fine.

Another crappy shot of the board after I cleaned it...

The contacts for the turn sigmals are shown here in the lower right. I cleaned them...

And added a spot of di-electrec grease to all the contacts during re-assembly:

This spring I am holding helps snap the rocker switch into hi and lo modes. The rocker switch (left) and the arm are both installed back on the board.

Then the plate goes back on and the two halves get screwed back together.

The good news it that this is really easy to do. The bad news is that it did not fix my problem. Still looking for ideas.

bb

[Mopar1973Man]

Something is wore out in that assembly... Plastic piece wore out? How about he copper contacts is there enough wear that the sliding copper pieces are not holding tight ot the board?

[billy bee]

Something is wore out in that assembly...

Nope. The switch is good. I figured out a continuity test for the switch if the hi/lo function fails. It is essentially a 3-wire switch with lthree large spades leading into the wiring harness and a 4th large spade for the flash mechanism (as in pull the stalk toward you to flash-to-pass).

In the picture below you can easily see the array of spades that connect into the wiring harness. The four largest spades (in the bottom row from the lower left corner) conduct power for the hi/lo function. Counting from the left let's call them poles 1 thru 4. Check resistance between poles one and two. If the resistance is high (infinite), click the stalk as if to dim your high beams. If the resistance remains high, take it apart and clean it up. If the resistance is low (<1 ohm) then check resistance between poles two and three. There should be infinite resistance between them. Click the stalk again and the resistance should drop to <1 ohm if the switch is working properly.. If not, then disassemble the switch and clean it up. If there are any burned connections or melted plastic, buy a new one of a known good used one.

---------- Post added at 09:41 PM ---------- Previous post was at 05:19 PM ----------

Forgot to tell you what my problem turned out to be. It's the headlight switch. I was doing pin checks with the multifunction switch installed in the car. I was trying to check voltage and resistance again. Zero volts! Juice is not even getting to the multifunction switch. Pulled out the headlight switch and cleaned it up and everything works fine.

BTW, the harness block was melted and the contacts had melted plastic on them. Too much heat at the switch. Probably a good idea to run a relay in there. I have not figured out how to do it. But there is too much juice running through that switch.

bb

[Mopar1973Man]

I don't think its too much juice but a weak connection in the switch that created the hot spot. If you clean it up and get a solid connection the hotspot should go away..

[98whitelightnin]

I pulled out of the garage this morning and the headlights wouldnt come on for me either. How do you clean the headlight switch?

[billy bee]

I pulled mine out to replace the switch and the switch was fine. Mine had a bad connection between the switch and the wiring block/harness that heated up and mented the harness leading to the switch. (Excessive resistance in the wiring creates heat.) So, I went to a salvage yard and clipped the harness out of a newer truck (that had heavier wires). I had to replace the plastic harness block with the used one I got. Took some time getting all the wires out of the burned block, but I spliced in a few new wires (that were shot) and clipped them all into the new/used wiring block, and I have been good to go. I used some electric grease on all teh connections and made sure they were all tight...Good luck.bb

[98whitelightnin]

I pulled mine out and started messing with it and it started working. I hate that it did that because now when I forget about it they wont work again. I wonder if we could take the whole assembly out of the newer 2nd gens with the little knob you turn, instead of the pull knob like we have, and make them work with our trucks?

[dracozny]

I pulled mine out and started messing with it and it started working. I hate that it did that because now when I forget about it they wont work again. I wonder if we could take the whole assembly out of the newer 2nd gens with the little knob you turn, instead of the pull knob like we have, and make them work with our trucks?

pull knob came with the trucks equipped with fogs. my 99 has a turn switch and no fogs.