M35a2 flasher problem

[Lenny]

I got this truck a few months ago and I have never had any problems with the flashers until the other day. I don't know if it is related, but I'm constantly forgetting that theses flashers don't automatically cancel like my civilian vehicles do. So consequently I'll almost constantly forget to cancel them. I'm trying to be better about this and with a bit of patience perhaps I will.

Last week while driving I happened to look down and I noticed that the flashers had been left on for about five minutes, and instead of flashing, the green indicator light on the column switch was on constant and not flashing. And depending on which side was selected either the right or left vehicle lights were on constant as well.

I've read about this on other threads and good grounds were mentioned. I've checked this and I don't think my problem is grounds because all my lights are brightly lit, and also the fender well ground wire is also making a good connection. In fact if you unground that wire the light will go out, an opposite state from what I have.

On the other old thread I happened across one guy mentioned that he had found that on many of these flashers the circuit board develops cold solder joints. He remedied the situation by heating the potting compound until it was soft. He then picked it off the board and he re soldered the faulty connections. To remove the compound he said that you could use a heat gun, (which I don't have), or you could also bake the flasher in a 250 degree oven for a period of time. This sounds a bit like an ambient temperature destruction test but at over 45.00 for these I'm inclined to try it.

My flasher is a sealed solid state unit which appears to be potted on both sides. It has a with a large heat sink and a three pin connector. The flasher was made by Nartron. The part number is: 11613631, NSN 5945-00-789-3706

So my questions are:
1. Is it possible that the extended periods that it was left on flashing caused it to fail?
2.Am I correct in assuming that all my grounds are probably OK seeing as how the lights are all on with normal brightness, and the indicator light goes off completely when the fender well ground is removed?
3. Has anyone else ever tried to repair one of these as I have described?
4. Given the symptoms I mentioned, and the chain of events leading up to them is it at all likely that it could be anything else?
Thanks in advance for your input. It will be most sincerely appreciated. Lenny

 

[rustystud]

I got this truck a few months ago and I have never had any problems with the flashers until the other day. I don't know if it is related, but I'm constantly forgetting that theses flashers don't automatically cancel like my civilian vehicles do. So consequently I'll almost constantly forget to cancel them. I'm trying to be better about this and with a bit of patience perhaps I will.

Last week while driving I happened to look down and I noticed that the flashers had been left on for about five minutes, and instead of flashing, the green indicator light on the column switch was on constant and not flashing. And depending on which side was selected either the right or left vehicle lights were on constant as well.

I've read about this on other threads and good grounds were mentioned. I've checked this and I don't think my problem is grounds because all my lights are brightly lit, and also the fender well ground wire is also making a good connection. In fact if you unground that wire the light will go out, an opposite state from what I have.

On the other old thread I happened across one guy mentioned that he had found that on many of these flashers the circuit board develops cold solder joints. He remedied the situation by heating the potting compound until it was soft. He then picked it off the board and he re soldered the faulty connections. To remove the compound he said that you could use a heat gun, (which I don't have), or you could also bake the flasher in a 250 degree oven for a period of time. This sounds a bit like an ambient temperature destruction test but at over 45.00 for these I'm inclined to try it.

My flasher is a sealed solid state unit which appears to be potted on both sides. It has a with a large heat sink and a three pin connector. The flasher was made by Nartron. The part number is: 11613631, NSN 5945-00-789-3706

So my questions are:
1. Is it possible that the extended periods that it was left on flashing caused it to fail?
2.Am I correct in assuming that all my grounds are probably OK seeing as how the lights are all on with normal brightness, and the indicator light goes off completely when the fender well ground is removed?
3. Has anyone else ever tried to repair one of these as I have described?
4. Given the symptoms I mentioned, and the chain of events leading up to them is it at all likely that it could be anything else?
Thanks in advance for your input. It will be most sincerely appreciated. Lenny

In all honesty don't try and repair it yourself. If grounding the unit doesn't help, just buy a new one from one of the many Surplus dealers. Otherwise you'll constantly be working on it. You'll fix one connection and then have two go bad the next time. Or you'll "over" solder into another circuit and cause real troubles. Of course if your doing this just for fun then go for it !

 

[Katavic918]

The circuit is very simple as I found out when my flasher module went bad. If all of your lights light it's probably not your harness wiring. However I have seen low battery voltage cause a turn signal to constantly stay on (in other vehicles)and for that matter I could possibly see a ground problem causing the same problem. For $50 I'd replace the module and that will most likely fix the problem.

 

[Lenny]

I have been reading though about how many guys have used a standard three terminal 24 volt electro mechanical flasher with good results. Napa lists an EG23 which also crosses to a Tridon and a few others. You just have to remove the old socket from the dead military unit and wire it onto the Napa. I suppose that you could also cut the plug off and solder the truck wires directly to the Napa unit, although I wouldn't go that route.

Those civilian flashers are relatively inexpensive too. The 12 volt ones are even cheaper. One guy says he used a 12 volt unit on his truck. He says that he put a 12 volt bulb in series with the ground terminal. When he hit the turn signal he dropped 12 volts across the bulb and the relay interrupted the 24 volts just as it should. Kind of ingenious. I don't know about connecting trailer lights to this kind of thing but I don't plan on doing that any time in the future.

But first I'm going to try to remove the potting with some heat. If that works and components are accessible I might try to fix the military module. If I can't I'll remove the plug. I'll let the group know how it works out. Best regards, Lenny

 

[gimpyrobb]

http://www.steelsoldiers.com/showth...sher-relay-civvy-conversion-how-to&highlight=

 

[pjwest03]

Memotronics sells the EF22 & EF23 24V civi flashers for ~$8. Also a good place to find most 24/28V bulbs by the box.

 

[silverstate55]

I have been reading though about how many guys have used a standard three terminal 24 volt electro mechanical flasher with good results. Napa lists an EG23 which also crosses to a Tridon and a few others. You just have to remove the old socket from the dead military unit and wire it onto the Napa. I suppose that you could also cut the plug off and solder the truck wires directly to the Napa unit, although I wouldn't go that route.

Those civilian flashers are relatively inexpensive too. The 12 volt ones are even cheaper. One guy says he used a 12 volt unit on his truck. He says that he put a 12 volt bulb in series with the ground terminal. When he hit the turn signal he dropped 12 volts across the bulb and the relay interrupted the 24 volts just as it should. Kind of ingenious. I don't know about connecting trailer lights to this kind of thing but I don't plan on doing that any time in the future.

But first I'm going to try to remove the potting with some heat. If that works and components are accessible I might try to fix the military module. If I can't I'll remove the plug. I'll let the group know how it works out. Best regards, Lenny

And this is just what I did with excellent results. The newer flasher units seem weaker than the older units, and I got tired of throwing money at a recurring problem. so I took one of my old non-op flasher units, used a milling bit in my cordless drill and removed the potting compound. Once the flasher housing was hollowed out, I drilled a hole in the top cover large enough for the Grote 24V flasher module to poke through, then glued it into place. I soldered new heavier wires into the original 3-pin socket and connected them to the civilian flasher.

It works like a CHAMP. No more turn signal/4-way flasher issues. Every time a flasher unit fails on one of my trucks, it gets this mod and I've never had to address that problem again. And yes, the grounds were all removed and cleaned up beforehand.

I also relocate my flasher units to the firewall, and run grounding wires directly from them to the frame.

Gimpyrobb points out an excellent thread detailing this. It works, and is less frustrating in the long run.

 

[Tracer]

In all honesty don't try and repair it yourself. If grounding the unit doesn't help, just buy a new one from one of the many Surplus dealers. Otherwise you'll constantly be working on it. You'll fix one connection and then have two go bad the next time. Or you'll "over" solder into another circuit and cause real troubles. Of course if your doing this just for fun then go for it !

Lenny, about 7 years ago my turn signals had the same problem, I checked connections, light bulbs, the ground, and still no signals. The only thing left was the flasher unit, so I changed it out and the turn signals worked again.

 

[rustystud]

Memotronics sells the EF22 & EF23 24V civi flashers for ~$8. Also a good place to find most 24/28V bulbs by the box.

I personally like the "Grote" 44860 better. Yes it costs more money but it is rated to 25 amps at 24 volts.