Electronic (push button) M-series Light Switch

[Stalwart]

OK, so I had a failure of the newer push button style blackout light switch. It has been acting up for some time, not always turning on the marker lights. At a recent event it failed in a "all lights on" condition. Upon internal inspection, 3 IC chips have overheated and burned, since the truck uses nothing but LED's it most likely isn't an overload condition, and in any case the IC chips only control relays anyway. Any thoughts? Since I didn't hook it up in the first place, I have no idea if it was grounded first before use, but it is separately grounded.

I really hate to use the three lever early model, it just doesn't look right in the beautiful dash that Damon (DMA251) made. Is there a newer upgraded one out there? Other than eBay, where is the best place to source these things?

I have decided to get a three lever to carry in the truck, it only takes about 15 min. and a phillips screwdriver to change it out.

Thanks in advance.

 

[Recovry4x4]

I'm not sure of a source other than Ebay. I have a used one if you are interested. I bought it new, it was in my M275A2 for over a year. When I sold the truck I removed it wih plans to put it in the Crusty the dropside. I've since decided to keep the 3 lever in there. It can be yours for $50 delivered if you want it. It never ever failed me in the 275.

 

[emmado22]

I just saw a brand new M1120A4 HEMTT fresh off the lowboy from depot.. It had the old style 3 lever in it.

 

[pigfoot63]

PM if interested I have a few new ones.

 

[Stalwart]

You can see what I mean by wanting to stay with the newer ones if at all possible.

 

[m16ty]

I liked the push button in my deuce until it tried to burn my truck down (switch had a complete meltdown). IMO they are a fire hazard. I'll never put another one in my truck.

 

[3cavtanker]

We had a problem with the new pushbutton switches burning themselves out if they were not installed properly. i was working for a contractor doing maintenance on HMMWV's. I was told that for installation, disconnect batteries, then connect the cannon plug and ground, mount the switch, then reconnect batteries. This prevented the dang things from burning out. As for one burning out later, I dunno. I actually preferred the lever type switch while I was deployed to Bosnia and Iraq and driving HMMWV's because I could change the lights by feel instead of having to take my eyes off the road.

 

[hndrsonj]

Mine after 3 years shorted the dash lights too. Like the look but..........

 

[nk14zp]

Can you replace the IC chips with ones with better specs. ?

 

[Stalwart]

I burned down another one but I found the cause. I have a three lever one in there for until I decide to do a proper fix. The back EMF from the relays was toasting the IC's. I have since gotten some relays with diodes to short the back EMF. Back EMF from a relay can go in excess of 100V, which would fry nearly any normal IC.

 

[papakb]

Electronic lightswitch

I've run an electronic light switch in my M996A1 for about 3 years now and have not experienced any problems with it. One thing that needs to be mentioned when installing them is that they need a good ground to the body of the vehicle. Without this they can do some wierd things including catching fire.

The light switch looks more modern in the vehicle but it has some drawbacks that should be considered before installing one. I find the fact that even after all the time this switch has been installed I still have to look at it to operate it! The 3 lever switches can be operated simply by feel. The other thing I don't like about it is that it requires 2 pushes to actuate a function.

Kurt Lesser

 

[emmado22]

Those switches suck plain and simple. They are high on the cool factor, but thats outweighed by the possibility of it burning the vehicle up.. There is a reason all the rebuilds and new trucks all have the 3 lever in them instead of that POS.

 

[alpm3]

they need a realy good ground new ones come with a additional groud wire

 

[emmado22]

The extra ground wire, when properly installed still doesnt prevent it from frying out. The bottom line is the electronics inside the switch are too sensitive to voltage spikes/drops on start up/shut down. You can run the ground wire directly to the batteries, the switch will still fry out eventually.

The Army used the 3 lever switch for several decades, they experimented with this POS, and have gone back to the 3 lever.. Whats that tell you?

The only one who made out on that deal was the contractor who makes them..

 

[Stalwart]

I'm putting diodes across the relay coil to keep the reverse voltage to .7V. If it still fries my last switch it is the 3 lever from then on.

 

[Heavysteven]

Mine stopped working after 2 months. Ground was to bare metal on the dash. So old three leer is back in.

 

[m16ty]

Those switches suck plain and simple. They are high on the cool factor, but thats outweighed by the possibility of it burning the vehicle up.. There is a reason all the rebuilds and new trucks all have the 3 lever in them instead of that POS.

I loved mine while it lasted and told everybody how good it was. That was until it almost burnt my truck down. It was grounded good so I don't think that was the problem. I was lucky I just happened to be in the truck when it shorted out. I started smelling melting plastic and by the time I figured out where it was comming from, the switch was too hot to handle with bare hands. I did manage to get it unpluged (burning my hands in the process) before it burst into flames.

Never again. As long as the 3-lever is still available I'll never put another push button in. IMO it's just not worth the fire hazard. Well I guess I would maybe consider another push button if somebody could modify them where they wouldn't catch fire.

 

[Stalwart]

Well I guess I would maybe consider another push button if somebody could modify them where they wouldn't catch fire.

That sir is my plan, to make mine foolproof. I'm not going to recommend one to anybody though. Relays, diodes and small circuit breaker SHOULD make one safe. Mine will only have to handle relay switching current. Plus I'll keep a 3 lever on board.

 

[cranetruck]

That sir is my plan, to make mine foolproof. I'm not going to recommend one to anybody though. Relays, diodes and small circuit breaker SHOULD make one safe. Mine will only have to handle relay switching current. Plus I'll keep a 3 lever on board.

Stuart, to make it fool proof, install a switch to turn it on/off, like any electronic device, it should not be on while starting or shutting down the truck engine. Protecting against "load dumps" from bad battery connections, for example, is expensiive and most likely left out in the design. That's why the military uses the MX-7777 units with radios and intercom installations (got one both in the deuce and the 8x.
I like my 3-lever switches and see no reason to switch to push-button style.
Edit: Added image of MX-7777 in the deuce.

 

[mhb285]

I wonder if that is causing the small arc when i disconnect my batteries when I'm done playing with my truck?