Electrical Gremlins. HMMWV M1097R1.

[RogerThat!]

I know you guys hate these kinds of questions. But I'm having fits with the lights on my M1097. The truck starts right up and runs fine. Good oil pressure, no blow by, etc.

I have replaced the three lever light switch, because I wasn't getting any power out to any of the lights except for the headlights.

Now, I have tail lights and front running lights on driver side. But not on passenger side. Which is weird.
Marker lights work all around.
No turn signals. Although the light on the turn signal switch light up. But not blink...just steady.
NO headlights, which worked for a while after I bought it.
No dash panel or gage lights.
Horn works now, but only when in Service Drive selector.

So it is really goofy. I guess I need to chase grounds. I have the trouble shooting guide (which is awesome) and the operator's manual and service manuals from this site. Thank YOU all.

Any other input or suggestions? Sooner or later I wanna get this thing on the road.

 

[NDT]

Crazy stuff happening with turn signals can be the lever being defective or bad grounds at the lamp units. Headlights that worked but now don’t could be burned out bulbs or grounds again.

 

[RogerThat!]

Thank you for reply.

I think I better start by checking the grounds and making sure they are clean and making good contact. I imagine the dissimilar metals and aluminum oxide causes lots of problems here.

Would explain why one side works and other doesn't...

Hate to keep buying parts without knowing which really are bad. Was taught not to do it that way back in the old days.

 

[Mogman]

The aluminum body is not used for grounding, all grounds find there way back to a few tie points, one is behind the instrument panel. it goes through the aluminum body with a bolt to a harness connection on the other side of the fire wall, there and the back of the engine are good places to start, and of course the grounding points at the devices themselves.
One thing to watch for is the harness connections on the back side of the headlights, sometimes they get switched make sure the tags match from the back side to the headlight wires and of course those are good places for corrosion also.
Open up the turn signals and also check the bulbs and for corrosion, if the brake lights work those are the same lamps used for turn signals on the rear.
The turn signals, brake lights, horn and dash lights work in service drive not when the lever is pointing up.

 

[RogerThat!]

Thanks, Mogman! That is some great info. I'm really impressed by the support I have already gotten on this board.

I will attack that tomorrow!

Roger

 

[INFChief]

The aluminum body is not used for grounding, all grounds find there way back to a few tie points, one is behind the instrument panel. it goes through the aluminum body with a bolt to a harness connection on the other side of the fire wall, there and the back of the engine are good places to start, and of course the grounding points at the devices themselves.
One thing to watch for is the harness connections on the back side of the headlights, sometimes they get switched make sure the tags match from the back side to the headlight wires and of course those are good places for corrosion also.
Open up the turn signals and also check the bulbs and for corrosion, if the brake lights work those are the same lamps used for turn signals on the rear.
The turn signals, brake lights, horn and dash lights work in service drive not when the lever is pointing up.

I do believe that the light housing mounting bolt holes are grounds to the light separation plates inside the housing. Those bolt holes must be clean and the wire mounting points on the plates must be corrosion free. Same for the ground wire at the light housing as well as all other grounding points.

 

[INFChief]

Take a close look at the cannon plugs on the light switch and turn signal arm. Make sure no sockets or pins on either the male or female connections are bent or pushed back inside the connector. I’ve also see lighting circuit gremlins pop up due to bare wires and shirts at the trailer receptacle.

 

[Retiredwarhorses]

The better question is, where did you purchase the replacement parts? Is it OEM or Chicomm

 

[RogerThat!]

I have been out there all morning. The turn signal switch checks out. But while the light for the flasher comes on, it doesn't flash.

I do have a couple of bulbs out, so will replace those. The tail light assemblies are of two different eras. One has all LED's like those on my M1102. The other is a mix of incandescent and LED. So, older. Should that matter? I'm thinking no.

The master light switch came from West Kentucky Surplus. I don't see any Made in PRC stamps or anything on the unit or packaging.

Dang headlights still don't light. I need to figure out why, because they did before I replaced the three lever light switch. Maybe I will stick the old one back in and see what happens.

Bloody Gremlins.

 

[Mogman]

Time to get the meter out and do some troubleshooting, are you getting power to the dimmer switch?
And yes LEDs can make a difference but if it is a problem it would only affect that side, the other side should still work.
I went and looked at the switch, the one shown at least looks OEM.
I still ask on every purchase I make, most of the recognizable names will be honest about it.

 

[RogerThat!]

I'm going to check the dimmer switch next. I never could get a difference between high and low beams before the headlights stopped working. But I will see what voltage is coming out next.

RDS

 

[Retiredwarhorses]

I have been out there all morning. The turn signal switch checks out. But while the light for the flasher comes on, it doesn't flash.

I do have a couple of bulbs out, so will replace those. The tail light assemblies are of two different eras. One has all LED's like those on my M1102. The other is a mix of incandescent and LED. So, older. Should that matter? I'm thinking no.

The master light switch came from West Kentucky Surplus. I don't see any Made in PRC stamps or anything on the unit or packaging.

Dang headlights still don't light. I need to figure out why, because they did before I replaced the three lever light switch. Maybe I will stick the old one back in and see what happens.

Bloody Gremlins.

there are no PRC made in china markings….they are crap copies

 

[Mogman]

there are no PRC made in china markings….they are crap copies

So the switches coming from WKS are knockoffs?

 

[RogerThat!]

I'm going to turn an eye to grounds. Replace bulbs. Then see what I get. I hope my switch isn't a PRC knock off. That would cheese me off.

 

[Retiredwarhorses]

So the switches coming from WKS are knockoffs?

No idea, but most sold on eBay and from all these hmmwv parts sellers are Chinese knock off, the only way to tell for sure On the 3 lever switch is the paint “CARC” and proper stencil of Date, cage code and date, anything else is aftermarket.
Which is why I asked where it was purchased from, post a picture of the new switch.

 

[RogerThat!]

I am going to go pull the switch and look. I will post a picture of the markings. Thanks for the info/tip.

Roger

 

[Mogman]

No idea, but most sold on eBay and from all these hmmwv parts sellers are Chinese knock off, the only way to tell for sure On the 3 lever switch is the paint “CARC” and proper stencil of Date, cage code and date, anything else is aftermarket.
Which is why I asked where it was purchased from, post a picture of the new switch.

I don't see any of those markings on the pictures listed on their web site, but other than that it looks legit,, these are good things to know!!
Always learning!!
Thanks RWH!

 

[RogerThat!]

Well, neither switch has a stencil of date etc. The old one has been painted sand, was OD green.

The old one has manufacturer's name. But no NSN. The new one has NSN but no manufacturer. Just a code. Funny thing is the code, 5A910, is stenciled on the old one but stamped on the newer one.

That code seems to be on all of these things.

The MIL-PRF-11021 code for the manufacturing spec of the switch is on the new one but not the old one.

Anyway, here are the photos,

 

[Retiredwarhorses]

Well, neither switch has a stencil of date etc. The old one has been painted sand, was OD green.

The old one has manufacturer's name. But no NSN. The new one has NSN but no manufacturer. Just a code. Funny thing is the code, 5A910, is stenciled on the old one but stamped on the newer one.

That code seems to be on all of these things.

The MIL-PRF-11021 code for the manufacturing spec of the switch is on the new one but not the old one.

Anyway, here are the photos,


View attachment 902324View attachment 902325View attachment 902326View attachment 902327View attachment 902328

im confused…which is e new one? Aurora Cord and Cable is a legit mfr…
take a pic of the face of the switch as well, it appears they are both used…?

 

[Retiredwarhorses]

Here is the company under CAGE code 5A910

About ADG – Aurora Defense Group

www.auroradefensegroup.com