2003 M1078 A1/ Tell me about the push button Light Switch Please

[Lugnuts]

Alright, color me stupid, I can turn on Stop Light and Turn Signals, and all lights off. That is the extent of it. I have two low mileage units that do the same thing so I figure it is me having the trouble. How to diagnose or how to work, that is the question.
Thank you guys.
Lugnuts

 

[Keith Knight]

press Ser Drive then enter for head lights. Most of the time I have to press enter very hard and hold it and sometimes multiple times. Some times repeat the process. The enter button isn’t the most responsive. I did open it up and clean some green oxidation off but it didn’t seem to help.

 

[Ronmar]

Yep, service drive and enter should enable the stop, turn-signals and headlights...

 

[Lugnuts]

Yep, service drive and enter should enable the stop, turn-signals and headlights...

If that doesn't work does it mean it broken or is it on a module?

 

[Lugnuts]

View attachment 939918
press Ser Drive then enter for head lights. Most of the time I have to press enter very hard and hold it and sometimes multiple times. Some times repeat the process. The enter button isn’t the most responsive. I did open it up and clean some green oxidation off but it didn’t seem to help.

You can open them up? Good to know. Anything special going to jump out or all self explanitory?

 

[Ronmar]

If that doesn't work does it mean it broken or is it on a module?

Check and make sure the switch assembly is properly grounded. They can act wonky when they are not grounded. You can also pull the switch and jumper the appropriate pins in the harness connector to enable brake, turn and headlights to test those circuits...

 

[Lugnuts]

I will check that out! Thank you

 

[TOBASH]

Are they backwards compatible with mechanical switches? On the HMMWV forum we hear these same electronic switches like to catch fire.

 

[GeneralDisorder]

Are they backwards compatible with mechanical switches? On the HMMWV forum we hear these same electronic switches like to catch fire.

Yes. But the push-button switches aren't supposed to be used on the HMMWV. They are for the FMTV, which has a 12v lighting system. The HMMWV lighting system is 24v - which likely has something to do with HMMWV's having them catch on fire AND it could be that they aren't being grounded properly as that has caused problems with these switches. They MUST be grounded, but the mechanical switch housing doesn't need a dedicated ground like the push-button switch.

 

[juanprado]

Narton makes a new model of the pushbutton that has a deeper face and fits the hmmwv dash better.

I have that on my hmmwv with no issues. Also have the other style on my m923. Both require a supplemental ground wire.

 

[TOBASH]

I will be swapping my pushbutton for mechanical. I like being able to open and fix.

When did I become unteachable and become an old dog?

 

[Ronmar]

I will be swapping my pushbutton for mechanical. I like being able to open and fix.

When did I become unteachable and become an old dog?

its a slow process until one day you wake up and there you are...

 

[Lugnuts]

Are they backwards compatible with mechanical switches? On the HMMWV forum we hear these same electronic switches like to catch fire.

I'm new to these switches. If you are attempting to tell me there are replacement switches which are better, please say. I haven't heard of any catching fire so please be straight forward. Thank you really!

 

[GeneralDisorder]

I'm new to these switches. If you are attempting to tell me there are replacement switches which are better, please say. I haven't heard of any catching fire so please be straight forward. Thank you really!

The FMTV always used the push-button. That is due to it's unique (in the military) 12v lighting system. Nothing else used them.

However, all the other military vehicles use the same mounting format and same wiring (but 24v) but with a lever-operated purely mechanical switch. So you can get one for any truck.... HMMWV, 800-900 series, M35's, and a great many others.... and install it on your FMTV and they are plug and play.

 

[Lugnuts]

The FMTV always used the push-button. That is due to it's unique (in the military) 12v lighting system. Nothing else used them.

However, all the other military vehicles use the same mounting format and same wiring (but 24v) but with a lever-operated purely mechanical switch. So you can get one for any truck.... HMMWV, 800-900 series, M35's, and a great many others.... and install it on your FMTV and they are plug and play.

Didn't know that and thank you for the reply!!!
So then is it better to go back to the mechanical than the pushbutton? Even as far as cost and dependability. Application is fire service

 

[Ronmar]

Didn't know that and thank you for the reply!!!
So then is it better to go back to the mechanical than the pushbutton? Even as far as cost and dependability. Application is fire service

Once their operation is understood, the 3 lever is pretty robust and typically does not act wonky

 

[GeneralDisorder]

The mechanical switch is undoubtedly more common, more reliable, cheaper, and less complex. But you actually don't need to use a military switch at all and really that just complicates the truck for your fire department vs. installing an old-school pull-style headlight switch like is seen on old Chevy trucks, etc. Simple on/off and you get service drive and that's it. Don't really need any of the other modes. This will of course require some wiring but the process is well documented. Acela does this to all their trucks because civilians rarely (ever?) need blackout drive modes, and the parking light mode can be ignition switched so it's just always on when you turn it on. The dash lights can be run through the dimming function (rotate) of the push-pull headlight switch.

All that being said - I do like the pushbutton for it's novelty factor and 99% of the problems were with early models, and then ongoing occasional issues with the grounding connection being poor or not present. I have my original that works just fine, but replaced mine with a brand new one that came along for a crazy good deal (new writing on the buttons vs. my original) so I have my original and a second brand new one as backups.

 

[Ronmar]

yea there are other ways to do this...

 

[Lugnuts]

Once their operation is understood, the 3 lever is pretty robust and typically does not act wonky

I like my Light Switches a little on the "wonky side" LOL Thanks again.

 

[TOBASH]

The mechanical switch is undoubtedly more common, more reliable, cheaper, and less complex. But you actually don't need to use a military switch at all and really that just complicates the truck for your fire department vs. installing an old-school pull-style headlight switch like is seen on old Chevy trucks, etc. Simple on/off and you get service drive and that's it. Don't really need any of the other modes. This will of course require some wiring but the process is well documented. Acela does this to all their trucks because civilians rarely (ever?) need blackout drive modes, and the parking light mode can be ignition switched so it's just always on when you turn it on. The dash lights can be run through the dimming function (rotate) of the push-pull headlight switch.

All that being said - I do like the pushbutton for it's novelty factor and 99% of the problems were with early models, and then ongoing occasional issues with the grounding connection being poor or not present. I have my original that works just fine, but replaced mine with a brand new one that came along for a crazy good deal (new writing on the buttons vs. my original) so I have my original and a second brand new one as backups.

Link for swaps to civilian push/pull light switches please.

I see the TouTube link BUT id like a more detailed description with schematics and or wire numbers and pushbutton replacement part numbers.