M109a3 wires

[digitaldust]

Hay M109a3 guys few questions

1 what is the plug on the box body behind the cab it has 2 wires plugged on a
terminal that is bolted out side the box near the bottom pass side

2 fan and fan box there is a box on the wall that said fan control 24v i guess from where

3 is there a wire from the batt box to the body for 24v maybe is missing?

I have no power 24v in the box anything i do

 

[sarge_3ad]

Question number 1 and 3 go together. That terminal is called a circuit breaker. And to answer question 3, there should be a lead that goes from the battery to that breaker. That will power your 24volt system.

Back to question 1. You may find an additional wire dangling there off the cable. That goes to a extra fuel pump for the fuel to the van body personnel heater. Many of these M109's don't have those heaters. Out of my 10 years in the military, and the many M109's I was issued, I only had one truck that had a personnel heater in back. When it worked, it was loud, but it would get warm enough in there that you could work in your skivvies.

Question # 2. The box on the wall is a power inverter. The switch you see for the fan runs the exhaust fan that's located in the rear left corner. Also, once you restore your 24volt power, your 2 dome lights in the van body should work. The switch for those is right above the main door , to the right.

I've attached the schematic for you to use. I might also suggest you get a CD with all the Tech Manuals for the duece on it. It sure comes in handy.

 

[wsucougarx]

Ok, exactly what can be powered or what gets power via the 24v system? My lights don't seem to come on in the van when switched to the 24v system. Is there just that tiny 14g wire that powers the van box?

 

[wikallen]

That wire at the circuit breaker is you 24volts feeding the box. I have that running the 24volt lights, a 24volt to 12volt dc converter to run a cooler or phone charger, and a 900watt 24vdc inverter powering a fridge and a laptop in the back of mine.

Get a multimeter, check for 24volt coming in from the wire from the battery at the circuit breaker. Then plug that back in, and unplug the wire from the top of the breaker leading up to the box. Check for 24vdc from the top of the circuit breaker. If you have 24volts coming from the top of the circuit breaker, then plug the wire back in leading to the box. Check your lights again and if still no go, will have to check the wires coming inside.

 

[skuhler]

Very valuable info. I've got an M109A2 and I'd like to wire an electric heater into that heater circuit. I see on the diagram the multi pin connections, I'm guessing those are the ones on the front wall? Would you have a pin out schematic on those plugs? Also, any idea where I can get some matching ones? I've got a WT-22 heater and it's had a standard 120v plug put on the cable.

 

[Katahdin]

That's not going to work, the heater circuit is 24 volt DC, your heater is 120V AC.

 

[skuhler]

That's not going to work, the heater circuit is 24 volt DC, your heater is 120V AC.

OH, I just looked in the circuit box and saw the wire sticking out of the circuit breaker and assumed it was 120v.

 

[Katahdin]

There are both 120V AC and 24V DC circuits in the M109 box, in post #5 you called to attention a 24V DC one.

You could plug your heater into the 120V AC outlets running down the side, you just need either generator or shore power to feed into the breaker panel.

 

[skuhler]

There are both 120V AC and 24V DC circuits in the M109 box, in post #5 you called to attention a 24V DC one.

You could plug your heater into the 120V AC outlets running down the side, you just need either generator or shore power to feed into the breaker panel.

Yes, I've done that. Hooked up a gen outside and fed the 120v system.

I was looking again at that breaker, it's 120v. It feeds a line numbered 704 that disappears into the wall. Does that go into the converter? Or where does it come out in the van?

I really need to get a CD with the wiring diagrams on it.

Thanks for your help

 

[Katahdin]

704 goes to the AC to DC transformer. It powers the 24 volt circuits when connected to generator power, this is to prevent draining the starter batteries.

 

[Jericho]

some of the ac dc transformer boxes had a built in heater, the control switches are blocked off now, BUT the very unit is available on line occasionally I found one last year and installed it, In the north east we call them a milk house heater , ill post some pics when i get a spare moment

 

[skuhler]

704 goes to the AC to DC transformer. It powers the 24 volt circuits when connected to generator power, this is to prevent draining the starter batteries.

Ah, ok. I'll remember that. Thanks for the info, it was very helpful. Do you think I'd be okay wiring the heater direct to that breaker for the 120v? I've got other appliances running on the two 120v side lines and a 2000 watt heater might be too much for those breakers.