5 ton battery switch inoperable

[kendelrio]

All-
One of the issues I have with my 5 ton is the battery switch will not kill electrics to the starter or dash gauges. In the off position, it is possible to still start the truck and my gauges will eventually drain my batteries.

To "fix" this and add additional security to the truck, I've installed a heavy duty inline battery switch as such:



I was reading the TMs here at work (have I mentioned I love my job sometimes?) and am doing some "desktop troubleshooting".

Based on the diagrams below, my issue is with the switch itself as based on the "commonalities" of the problem (all electrics are on, not just starter OR battery etc).




I looked in table 3-2 (troubleshooting section) and my issue wasn't addressed.

Am I chasing this problem in the right direction?

If so, which one of us or our members or vendors have a replacement for it? I'm looking for NOS or working used.


Thanks in advance!

 

[NDT]

Nothing goes “clunk” when you turn the battery switch? Sounds like the protective control box has a stuck on solenoid.

 

[kendelrio]

Nothing goes “clunk” when you turn the battery switch? Sounds like the protective control box has a stuck on solenoid.

The question I have, though, is shouldn't the battery switch kill power to the PCB?

From what I'm seeing, the switch is "upstream" from the PCB. Turning the switch off should kill electricity to the entire circuit and that isn't happening, so unless I'm reading power flow incorrectly, my first step should be the battery switch.

 

[NDT]

The question I have, though, is shouldn't the battery switch kill power to the PCB?

From what I'm seeing, the switch is "upstream" from the PCB. Turning the switch off should kill electricity to the entire circuit and that isn't happening, so unless I'm reading power flow incorrectly, my first step should be the battery switch.

That would mean the battery switch is failed closed. I have never seen that.

 

[kendelrio]

That would mean the battery switch is failed closed. I have never seen that.

So again, my question is this I guess....

Is the PCB in line *before* the switch? As in it gets power regardless or is power sent to the PCB through the switch?

As I said, my guages etc all stay on. Shouldn't the switch kill that?

 

[kendelrio]

OK, after more digging, I found the following illustration:



Based on this, all of my gauges are connected through the switch to the battery. Logically, my switch has failed in the "closed" position, resulting in the above mentioned problems.


Thanks all.

 

[papakb]

It's a little hard to tell from the diagrams but is your battery switch breaking the line between the battery and ground or does it break the positive feed line? Breaking the ground lead should kill all power to the vehicle.

 

[kendelrio]

OK, after more digging, I found the following illustration:

View attachment 843009

Based on this, all of my gauges are connected through the switch to the battery. Logically, my switch has failed in the "closed" position, resulting in the above mentioned problems. I found one from Eastern Surplus and WI order it tonight.

Thanks all.

It's a little hard to tell from the diagrams but is your battery switch breaking the line between the battery and ground or does it break the positive feed line? Breaking the ground lead should kill all power to the vehicle.

That's where I'm stumped. Until I get home with my meter and can check, I don't know.

Logically (and I know logic and military don't always go together) it makes no sense for the PCB and gauges to be powered before the switch.

 

[marchplumber]

Keep us informed, Sir.....


Somehow, I can't "read tms" when I'm at work....hmmmmm

LMBO

 

[Micmada]

OK, after more digging, I found the following illustration:

View attachment 843009

Based on this, all of my gauges are connected through the switch to the battery. Logically, my switch has failed in the "closed" position, resulting in the above mentioned problems. I found one from Eastern Surplus and WI order it tonight.

Thanks all.

That's where I'm stumped. Until I get home with my meter and can check, I don't know.

Logically (and I know logic and military don't always go together) it makes no sense for the PCB and gauges to be powered before the switch.

The switch activates a relay in the PCB, I can hear it in the PCB when my PCB allows it (Ie when it is not humid). I assume if the relay stays stuck when the switch is back to off, all the dryer heater and ABS system will keep draining the battery. It seems all the switch does is activate a solenoid in the relay. It does not actually powers anything going through it for electrical protection reason. It is a power firewall system. . I think this is why the diagram is not an electrical one but a control diagram.

The other day I plaid with the battery switch while the engine was on, wondering whether, like in airplanes, you turn off the battery switch before the engine. It seemed like the alternator indicator was pushing to the right and almost over charging when I kept it off. Well, later during the next ride it seemed like my PcB did not like that at all - playing with relays at all when engine was running apparently.

After stopping at Walmart, when trying to restart, the battery switch would not activate the relay despite dry weather - the gauge needles would not kick on. I flickered it several times and it finally went on. Then I did not hear the relay clicks turning on the ABS system when I flipped the starter relay contact. The truck then started with ABS light on and I had an overcharge indication on my alternator. I had to switch on the fan and the lights so as to put the charge back in green. I did not want to stop the truck as I was at Walmart and drove it home for about 20 min with the fan on. Every time I switched the fan off while the truck was riding above 1000 rpm, I had over charge but not at idle.

arriving home I switch the fan off and revved up the engine and no over charge. Once turning off the truck and switching the battery and start switch back to activate the relays, the ABS relays clicked and the light went off. The truck started fine. Still not sure if it was me flickering that switch that caused all that, because I also installed a new blinker handle at Walmart that I picked up delivered at a UPS drop point. So maybe it was the new blinker switch it did not like, who knows. But the blinker switch is not connected to the PCB. It and the lights are an independent direct line to the battery I believe (+- the flasher in between).

This is one funky system. I wanted to install a new control box but I do not want to fry it, so I will wait for the new alternator to come in before doing that.

 

[kendelrio]

The switch activates a relay in the PCB, I can hear it in the PCB when my PCB allows it (Ie when it is not humid). I assume if the relay stays stuck when the switch is back to off, all the dryer heater and ABS system will keep draining the battery. It seems all the switch does is activate a solenoid in the relay. It does not actually powers anything going through it for electrical protection reason. It is a power firewall system. . I think this is why the diagram is not an electrical one but a control diagram.

The other day I plaid with the battery switch while the engine was on, wondering whether, like in airplanes, you turn off the battery switch before the engine. It seemed like the alternator indicator was pushing to the right and almost over charging when I kept it off. Well, later during the next ride it seemed like my PcB did not like that at all - playing with relays at all when engine was running apparently.

After stopping at Walmart, when trying to restart, the battery switch would not activate the relay despite dry weather - the gauge needles would not kick on. I flickered it several times and it finally went on. Then I did not hear the relay clicks turning on the ABS system when I flipped the starter relay contact. The truck then started with ABS light on and I had an overcharge indication on my alternator. I had to switch on the fan and the lights so as to put the charge back in green. I did not want to stop the truck as I was at Walmart and drove it home for about 20 min with the fan on. Every time I switched the fan off while the truck was riding above 1000 rpm, I had over charge but not at idle.

arriving home I switch the fan off and revved up the engine and no over charge. Once turning off the truck and switching the battery and start switch back to activate the relays, the ABS relays clicked and the light went off. The truck started fine. Still not sure if it was me flickering that switch that caused all that, because I also installed a new blinker handle at Walmart that I picked up delivered at a UPS drop point. So maybe it was the new blinker switch it did not like, who knows. But the blinker switch is not connected to the PCB. It and the lights are an independent direct line to the battery I believe (+- the flasher in between).

This is one funky system. I wanted to install a new control box but I do not want to fry it, so I will wait for the new alternator to come in before doing that.

You are absolutely correct. It turns out my battery solenoid was stuck, then my start solenoid went out. I bought the solenoids at O'Reilly before I came offshore for $32.00 each and will post a rebuild PCB thread when I get back in covering removal, disassembly, rebuild and reinstallation.

 

[kendelrio]

I wanted to install a new control box but I do not want to fry it, so I will wait for the new alternator to come in before doing that.

As far as installing a new PCB, if you have one already, awesome. If you don't and want to save some moolah, follow my post in aboit 10 days. I'll do parts and tools used, where to get parts etc.
Otherwise it's just unscrew the connector at the bottom, unbolt it from the firewall and put the new one in. Nothing will be fried as yoy aren't dealing with live voltage

 

[ToddJK]

I'm curious to see how these parts hold up since it's from a commercial auto parts store. Glad to see you put a battery disconnect in though, I have 2 installed on my deuce now, one on the dash and one under the seat (passenger). I had an indicator light, said it was 24v capable, but a cheap amazon light, which only lasted about a week until it burned out, lol. That's what I get for going to cheap I guess!

 

[Micmada]

As far as installing a new PCB, if you have one already, awesome. If you don't and want to save some moolah, follow my post in aboit 10 days. I'll do parts and tools used, where to get parts etc.
Otherwise it's just unscrew the connector at the bottom, unbolt it from the firewall and put the new one in. Nothing will be fried as yoy aren't dealing with live voltage
[/QUOTE]
I bought a new PCB but would be interested in a cheap alternative replacing the relays and printed circuit, to see if I can get away with it because I am not sure if it is my alternator or the PCB that is acting up. I saw some posts about bypassing the top relay or doing hot wire starts, and I am still not sure about a couple details.

 

[wheelspinner]

The switch activates a relay in the PCB, I can hear it in the PCB when my PCB allows it (Ie when it is not humid). I assume if the relay stays stuck when the switch is back to off, all the dryer heater and ABS system will keep draining the battery. It seems all the switch does is activate a solenoid in the relay. It does not actually powers anything going through it for electrical protection reason. It is a power firewall system. . I think this is why the diagram is not an electrical one but a control diagram.

The other day I plaid with the battery switch while the engine was on, wondering whether, like in airplanes, you turn off the battery switch before the engine. It seemed like the alternator indicator was pushing to the right and almost over charging when I kept it off. Well, later during the next ride it seemed like my PcB did not like that at all - playing with relays at all when engine was running apparently.

After stopping at Walmart, when trying to restart, the battery switch would not activate the relay despite dry weather - the gauge needles would not kick on. I flickered it several times and it finally went on. Then I did not hear the relay clicks turning on the ABS system when I flipped the starter relay contact. The truck then started with ABS light on and I had an overcharge indication on my alternator. I had to switch on the fan and the lights so as to put the charge back in green. I did not want to stop the truck as I was at Walmart and drove it home for about 20 min with the fan on. Every time I switched the fan off while the truck was riding above 1000 rpm, I had over charge but not at idle.

arriving home I switch the fan off and revved up the engine and no over charge. Once turning off the truck and switching the battery and start switch back to activate the relays, the ABS relays clicked and the light went off. The truck started fine. Still not sure if it was me flickering that switch that caused all that, because I also installed a new blinker handle at Walmart that I picked up delivered at a UPS drop point. So maybe it was the new blinker switch it did not like, who knows. But the blinker switch is not connected to the PCB. It and the lights are an independent direct line to the battery I believe (+- the flasher in between).

This is one funky system. I wanted to install a new control box but I do not want to fry it, so I will wait for the new alternator to come in before doing that.

Don’t do this.

The engine must be completely stopped BEFORE you turn the battery switch off. If you turn off the batteries before it’s done spinning the alternator output has nowhere to go and can and will smoke the PCB or the alternator.

 

[Micmada]

Don’t do this.

The engine must be completely stopped BEFORE you turn the battery switch off. If you turn off the batteries before it’s done spinning the alternator output has nowhere to go and can and will smoke the PCB or the alternator.

So I decided to install a solar panel on the roof to help batteries but it was a 12 volt charge. To prevent unbalancing of the batteries I ordered a couple cheap chinese solar battery balancers for 24v systems. Ever since I did that I have zero acting up from the alternator nor the PCB circuit. It seems as if battery unbalancing causes issues to the system. I noticed that there is a 12v cable going down through the floor to some equipment below. I am not sure what it powers. Anyone has any idea? It might have been the cause of my batteries unbalancing before I even put that solar panel. I am not sure.

 

[wheelspinner]

So I decided to install a solar panel on the roof to help batteries but it was a 12 volt charge. To prevent unbalancing of the batteries I ordered a couple cheap chinese solar battery balancers for 24v systems. Ever since I did that I have zero acting up from the alternator nor the PCB circuit. It seems as if battery unbalancing causes issues to the system. I noticed that there is a 12v cable going down through the floor to some equipment below. I am not sure what it powers. Anyone has any idea? It might have been the cause of my batteries unbalancing before I even put that solar panel. I am not sure.

Low speed on your heater fan. Not sure on anything else

 

[Micmada]

Low speed on your heater fan. Not sure on anything else

Interesting. Low speed on the fan did not seem to help at all at the time it was acting up, but high speed did temporarily remediate the problem before I installed the charge balancers.