Some lights work, other do not

[Skippy45]

Ok, here is my story/problem. I have 1991 m998 with the 6.2. 2 weeks ago while driving I noticed the volt meter jumping around. When I got home I went to adjust the setting on the Alt. It went from somewhat stabile to either on or off. 30+volts, or not charging. I purchased the grounding kit. (started off with the cheapest fix 1st.) Installed it, but that did not fix the problem. installed a new voltage regulator, adjusted the voltage and that problem is fixed. As I was driving it the next day I noticed that the turn signal lever would only light up if it was placed in the left turn spot. When I got home I checked it out and only the left rear light signal was working. The running lights work fine on all 4 corners. The brake light does not come on the right rear either. All the other lights work as they should. I hate chasing gremlins. Any one have any thoughts on this? I have not pulled the bulbs yet (that would by weird to have 3 bulbs bad all at once and the signal lever work in the left turn spot). I have not found anything on the forums with this problem.

 

[Mogman]

Check the bulbs first, you may have blown them with the bad regulator...

 

[Milcommoguy]

Ok, here is my story/problem. I have 1991 m998 with the 6.2. 2 weeks ago while driving I noticed the volt meter jumping around. When I got home I went to adjust the setting on the Alt. It went from somewhat stabile to either on or off. 30+volts, or not charging. I purchased the grounding kit. (started off with the cheapest fix 1st.) Installed it, but that did not fix the problem. installed a new voltage regulator, adjusted the voltage and that problem is fixed. As I was driving it the next day I noticed that the turn signal lever would only light up if it was placed in the left turn spot. When I got home I checked it out and only the left rear light signal was working. The running lights work fine on all 4 corners. The brake light does not come on the right rear either. All the other lights work as they should. I hate chasing gremlins. Any one have any thoughts on this? I have not pulled the bulbs yet (that would by weird to have 3 bulbs bad all at once and the signal lever work in the left turn spot). I have not found anything on the forums with this problem.

Free information and observations. NOT directed at anyone person, anytime, anywhere or any HMMWV. Just working the keyboard, burning bandwidth.

That's a nice gremlin story. Great information... But there are not called gremlins for nothing and no two are alike. Try and catch (work one) and the others may come around. Yea, messing with the new guy, BUT one just has to jump in and start at some place. Try not to go in circles chasing gremlins. Good to have the wiring diagram in hand or great knowldge of what goes where and how they interface.

Here's a guess. Turn signal selector switches a lot of those lamps in or out of the circuit. They do go bad. Hard to get a handle (did I say that) on the problem. Keep in mind the problems... But they may not be connected.

One at a time and smoke them out. puns there somewhere, CAMO

Good luck and have fun.

 

[TOBASH]

Free information and observations. NOT directed at anyone person, anytime, anywhere or any HMMWV. Just working the keyboard, burning bandwidth.

That's a nice gremlin story. Great information... But there are not called gremlins for nothing and no two are alike. Try and catch (work one) and the others may come around. Yea, messing with the new guy, BUT one just has to jump in and start at some place. Try not to go in circles chasing gremlins. Good to have the wiring diagram in hand or great knowldge of what goes where and how they interface.

Here's a guess. Turn signal selector switches a lot of those lamps in or out of the circuit. They do go bad. Hard to get a handle (did I say that) on the problem. Keep in mind the problems... But they may not be connected.

One at a time and smoke them out. puns there somewhere, CAMO

Good luck and have fun.

Sage advice from Milcom/CamO. Also look to see if flasher solenoid is going bad.

Cheapest thing is to check for bad lightbulbs.

If money is an issue always disconnect the battery before electrical work, and then check all contacts, check bulbs, then flasher control solenoid, and finally the overpriced switch.

 

[Skippy45]

Sage advice from Milcom/CamO. Also look to see if flasher solenoid is going bad.

Cheapest thing is to check for bad lightbulbs.

If money is an issue always disconnect the battery before electrical work, and then check all contacts, check bulbs, then flasher control solenoid, and finally the overpriced switch.

If it Was the switch or solenoid, why does it still work on one light? Then why the is the brake light only working on one side? All worked as it should until grounding kit and voltage regulator replaced. The running lights work fine too.

 

[Skippy45]

Check the bulbs first, you may have blown them with the bad regulator...

I will start checking bulbs in the morning. I would think if I had blown the bulb, the whole bulb, not just the part that "flashes"..

 

[Mogman]

Camo is right in that all those lamps go through the turn signal switch, for example it is how the right brake light becomes the right turn signal when the lever is moved up etc.
But I have seen those regulators go where the alt for at least some time is running WFO so loosing some bulbs would be the first thing I would suspect given the circumstances you describe, really easy to check also....

 

[Milcommoguy]

Sage advice from Milcom/CamO. Also look to see if flasher solenoid is going bad.

Cheapest thing is to check for bad lightbulbs.

If money is an issue always disconnect the battery before electrical work, and then check all contacts, check bulbs, then flasher control solenoid, and finally the overpriced switch.

Remote repair is one of those times that both parties need to be on the same page or it turn into a training session... AND that's OK, it's what we do here.

It gets a bit sideways when the problem is compounded with "I got this and that, and one of these too going on" Trouble shooting skills come out (along with the prints / drawings) and start the process of elimination and reconstruction back to standard, maybe even better that new.

While my responses may not be the 'easy fix" one is looking for, sorry. It is very difficult to diagnosis problems stated in a simple paragraph or two. Hence the sometimes long road down a rabbit hole or two with these threads, here we go. Yes, it is a fun ride. BUT for this old guy... I try to point to an obvious, check this or that. Like in check switch, or bulb or is in plugged-in? LOL with you...NOT at anyone.

So...while "lights out" may seem simple, there is a lot of points of failure along the way. (over voltage regulator YEP, that too)

In the end it will be a simple thing or two or compounded by a series of events that need to be reconstructed. (sounds like doctor talk)

Focused guessing is all I got while poking and prodding the problem based on provided info. And if the gang here hasn't notice, I poke a little bit at the OP to step up, dig in. Your are the "boots on the ground" so report out with good data. Pictures can speak a 1000 words. Just like an X-Ray.

HMMWV is a total all hands on deck machine IMO. All of the responses here are the collective brain trust of years of HMMWV and researching the TM's .

Start with the bulb/s, check for good and work it toward the switch, flasher and anything wire, connector, socket, loosey, goosey, rusted, busted and I am all out of guess.

GOOD LUCK...and is there a doctor in the house?

Don't be looking for the "flasher solenoid". I'am guessing that's not it, CAMO

Free information and observations. Usually not directed at anyone person, anytime, anywhere or any HMMWV.
Just working the keyboard, burning bandwidth and watching TV.

 

[Action]

I will start checking bulbs in the morning. I would think if I had blown the bulb, the whole bulb, not just the part that "flashes"..

The running light and the brake/turn are 2 different bulbs. You can see that when they are both on.
And in dual use bulbs, you just one of the filaments can burn out.
Easy check is to just swap the good brake light bulb to the other side. It is a good time tp look at the sockets for rust, too.

 

[Skippy45]

The running light and the brake/turn are 2 different bulbs. You can see that when they are both on.
And in dual use bulbs, you just one of the filaments can burn out.
Easy check is to just swap the good brake light bulb to the other side. It is a good time tp look at the sockets for rust, too.

Ok, problem I.D.ed.. I was looking for logical when none existed. Why just 3 out of 4 flashers not working, why not a side marker light or 2, or a running light? Thank you for the help.. It was just the flasher bulbs. I guess you are never 2 old to be amazed at the weirdness of stuff. Lesson learned. This is my 3rd 998 and everyone of them have taught me a lesson or 2. Glad it was not the turn signal switch.. OMG that is highway robbery for that little piece. Thank again.. now off to buy bulbs lol.

 

[Mogman]

Called it!!!

 

[Skippy45]

Called it!!!

You sure did..lol

 

[Mogman]

So, you understand that only the bulbs that were being used what the gen was running WFO got burned out.
So depending on how long it was before you noticed and how long you took to address the problem, you may have cooked the crud out of your batteries.
It would take some pretty high voltage to fry multiple lamps so all that was being thrust into your poor batteries.
So I would closely inspect your batteries for swelling, leaks and also electrolyte if they are standard lead acid batteries.

Edit, the wife and I were 42 miles down a 4WD only beach pulling a trailer when I noticed the voltage go well above normal, I immediately disconnected the 60A and reduced the power consumption all I could and left it running, it was 4 hours later until we reached pavement, 1/2 hour to eat the free hotdogs and another 1 1/2 hours to the house.

I had just installed $1100 dollars worth of Odyssey batteries and would not have been happy to cook them, had PLENTY of juice left when we got home.
Was the last time I will ever run a 60A alternator as your story is all too common.

 

[Skippy45]

So, you understand that only the bulbs that were being used what the gen was running WFO got burned out.
So depending on how long it was before you noticed and how long you took to address the problem, you may have cooked the crud out of your batteries.
It would take some pretty high voltage to fry multiple lamps so all that was being thrust into your poor batteries.
So I would closely inspect your batteries for swelling, leaks and also electrolyte if they are standard lead acid batteries.

Edit, the wife and I were 42 miles down a 4WD only beach pulling a trailer when I noticed the voltage go well above normal, I immediately disconnected the 60A and reduced the power consumption all I could and left it running, it was 4 hours later until we reached pavement, 1/2 hour to eat the free hotdogs and another 1 1/2 hours to the house.

I had just installed $1100 dollars worth of Odyssey batteries and would not have been happy to cook them, had PLENTY of juice left when we got home.
Was the last time I will ever run a 60A alternator as your story is all too common.

The higher voltage was only for a min or less (total time) as I was trying to adjust the voltage regulator. Those lights were not even being used at the time. zero lights were on. So logically none of then should of burned out. Just another weird adventure with the M998. Oh and those bulbs.. seen prices as high $16 a piece or $1 but $22 for shipping.. incredible .. found a box of 10 for under $5 finally. Fun stuff.

I always watch my gauges as I drive, so I noticed the jumping voltage right away. While I was driving it, never jumped into the yellow . After I got home and tried adjusting the voltage is when it jumped up to max output.

 

[Mogman]

That regulator was going bad before you even noticed it, the voltage was spiking up very high while you were driving it and using the brakes/turn signals, that is WHY you lost multiple bulbs, There can be no doubt about that, nothing weird about it just the normal way a 60A alternator fails.
Something fails and causes the transistor controlling the field to go intermittently WFO until the field current gets so high it eventually fries the circuit board and looks like this.

 

[TOBASH]

The higher voltage was only for a min or less (total time) as I was trying to adjust the voltage regulator. Those lights were not even being used at the time. zero lights were on. So logically none of then should of burned out. Just another weird adventure with the M998. Oh and those bulbs.. seen prices as high $16 a piece or $1 but $22 for shipping.. incredible .. found a box of 10 for under $5 finally. Fun stuff.

I always watch my gauges as I drive, so I noticed the jumping voltage right away. While I was driving it, never jumped into the yellow . After I got home and tried adjusting the voltage is when it jumped up to max output.

Those lights are not specific to HMMWV, so any 18 wheeler truck stop should have them.

 

[Mogman]

These are the best you can use as far as incandescent, they have dual filaments so if one burns out you might still have a working light, this is only an example as I did not search for the cheapest price, but $2 a bulb shipped is not too bad.

Qty-10 NOS Micro Lamps Incandescent ML-1683 28V 32CP S25 BA15S 6240000446914 | eBay

Emitted Light Characteristic. Light Center Length. Bulb Light Transmission Characteristic. If you have any complaints about your order. Any acceptable. Burning Position. Rated Average Life. 1.020 amperes nominal.

www.ebay.com

 

[Skippy45]

Got 10 for less than $5 at the local parts store. (had to buy/order the whole box)

 

[RJTM998]

Mine was like this with some lights working and some not. It ended up being grounding points at the lights. They were rusted and not making good ground.

 

[Skippy45]

Everything is running as it should.. went and got a little mud on the tire on thurs.