Electrical Starting Issue

[WhitePhoenix]

Gents, let me tell the tale to set the current scenario that presents itself to me right now. My deuce was bought and didn't run at the time. Well got everything buttoned up and went to start it for the 1st time, sparks shot out from the battery compartment but the engine did turn over. Closer inspection showed the connectors were cracked and weren't making good contact. Replaced them and went to try another start, the starter switch got a few cranks then the switch slipped due it not being tight to the dash, tightened it down and tried again, this time nothing. Looking through the tm's and broke out the multimeter to find the starter relay went bad, replaced it thinking my problem was solved but alas still nothing. Checked all the wires and ground, everything looks good. There is no clicking sound coming from the starter relay, so I'm thinking the switch is now bad, but any ideas are much appreciated.

 

[General Mcgregor]

Have you tried jumping the switch? Did you replace the relay with a new or used part?

 

[viejo]

I had this exact same problem. The sparks melted the terminals on the battery. It turns out (at least on my duce) the battery terminals and connections must be super clean. I had to buy a few new batteries before I figured it out. Now, every time I stop for any period of time, I completely disconnect the batteries and clean the connections, and cover the battery terminals. It''s a pain in the butt, but I have not had the issue re-occur. I hope this helps and it's that simple for you as well.

There is a post around here about this same issue, that's how I figured it out...

good luck

Hey, I just realized this is my first post; I come here when I have duce problems and Steel Soldiers has helped me figure out all of them - thanks.

 

[WhitePhoenix]

Have you tried jumping the switch? Did you replace the relay with a new or used part?

Im not familiar with jumping the switch, could you please explain? And the relay is new.

Viejo, the terminals on the battery are still good and clean, get the low air buzzer and good volts to the starter relay.

 

[Jeepsinker]

Unplug the two terminals from the rear of the switch and stick each one of the ends on a pair of needle nose pliers, or you can just use a piece of wire to do the same. If it turns over then the switch is bad. Some switches are bad right out of the box. Also, trace your ground wire from the rear battery to the frame and wiggle it at the frame. Sometimes the ring terminal will crack and break at the frame connection. Check the ground from the starter to the frame the same way.

 

[General Mcgregor]

You think your switch might be bad right? If you have your multimeter handy it should be pretty easy to test it. If you don't then you can use a jumper wire to close the circuit and bypass the switch. If it works then your switch is malfunctioning, if it doesn't then it's something else. I had a similar problem after I replaced my engine. Turned out I had spun one of the studs on the relay when I was hooking everything back up and broke the control wire off on the inside.

 

[WhitePhoenix]

I didnt mention but this is an '88 truck, so the 4 pin style in the rear of the switch. I would use the 2 prongs that protrude to jump-start the truck correct? Also, after i disconnected the starter switch, the rear of it came off and I've attached them what looks like some sort of overload happened.

 

[porkysplace]

I didnt mention but this is an '88 truck, so the 4 pin style in the rear of the switch. I would use the 2 prongs that protrude to jump-start the truck correct? Also, after i disconnected the starter switch, the rear of it came off and I've attached them what looks like some sort of overload happened.

This thread should help you .
[h=1]m35a2 twist style start[/h]

 

[meumar]

This thread should help you .
m35a2 twist style start

Here is a snippet from the wiring diagram for the four-terminal starter switch (TM 9-2320-386-24-1-2, pg 750).

 

[steelandcanvas]

It's an '88? Is it a dropside? (M35A2C) Do you know if it was previously Air Force owned? If so, we have a registry going for those trucks.

 

[Jeff Nelson]

I had this exact same problem. The sparks melted the terminals on the battery. It turns out (at least on my duce) the battery terminals and connections must be super clean. I had to buy a few new batteries before I figured it out. Now, every time I stop for any period of time, I completely disconnect the batteries and clean the connections, and cover the battery terminals. It''s a pain in the butt, but I have not had the issue re-occur. I hope this helps and it's that simple for you as well.

Something I've used for battery and ground connections is a paste called Coppershield. It looks like copper impregnated goo but seems to work well for high current connections. You need just a thin coat to seal connections from the atmosphere and thereby eliminate corrosion. Note that this stuff will be everywhere if you aren't paying attention to your fingertips...

 

[WhitePhoenix]

This thread should help you .
m35a2 twist style start

I have read through that thread, how do i specifically test that the twist switch is bad (as in where to put the connectors from the multimeter and what voltage/amps/resistance should I see)? The whole bypassing the switch is still a bit confusing aswell, if someone can point me as to which leads to use.


Steelandcanvas, yes it is an Airforce truck and on the registry.

 

[porkysplace]

I have read through that thread, how do i specifically test that the twist switch is bad (as in where to put the connectors from the multimeter and what voltage/amps/resistance should I see)? The whole bypassing the switch is still a bit confusing aswell, if someone can point me as to which leads to use.


Steelandcanvas, yes it is an Airforce truck and on the registry.

Post the wire numbers off the switch.

 

[WhitePhoenix]

Post the wire numbers off the switch.

118, 119, 127, 174 are the wire numbers.

 

[mikey]

I had this exact same problem. The sparks melted the terminals on the battery. It turns out (at least on my duce) the battery terminals and connections must be super clean. I had to buy a few new batteries before I figured it out. Now, every time I stop for any period of time, I completely disconnect the batteries and clean the connections, and cover the battery terminals. It''s a pain in the butt, but I have not had the issue re-occur. I hope this helps and it's that simple for you as well.

There is a post around here about this same issue, that's how I figured it out...

good luck

Hey, I just realized this is my first post; I come here when I have duce problems and Steel Soldiers has helped me figure out all of them - thanks.

My batteries arced once and it melted a hole in the battery and damaged some other minor items like the horn solenoid. I have since switched to batteries with stud terminals and that's all I use now.

 

[WhitePhoenix]

Just a quick question, on the back of the switch, which slots do wire 127 and 174 go to? The wiring diagram shows 74 and 74A going to B & D, and that's throwing me for a loop right now.

 

[porkysplace]

Just a quick question, on the back of the switch, which slots do wire 127 and 174 go to? The wiring diagram shows 74 and 74A going to B & D, and that's throwing me for a loop right now.

Maybe the pictures of the plug in this thread will help .
[h=1]Start Switch[/h]

 

[WhitePhoenix]

It did help sort of, just matched up the wires to their respective numbers and how the connector from the start plugged into the other receiver. And I finally understood how to bypass the switch, which I tried to no avail and pulling the starter tomorrow to get it checked out. Now the only new strange issue I have now is that the parking brake light won't come on the dash (did before), it does when I connect 117 and 118 with the pliers, but not when I reconnect the ignition switch.

 

[porkysplace]

It did help sort of, just matched up the wires to their respective numbers and how the connector from the start plugged into the other receiver. And I finally understood how to bypass the switch, which I tried to no avail and pulling the starter tomorrow to get it checked out. Now the only new strange issue I have now is that the parking brake light won't come on the dash (did before), it does when I connect 117 and 118 with the pliers, but not when I reconnect the ignition switch.

There is also a starter relay on the motor bolted to the side of the block that should be checked.
[h=1]Starter Relay help[/h]

 

[WhitePhoenix]

There is also a starter relay on the motor bolted to the side of the block that should be checked.
Starter Relay help

Yup that was the 1st thing I had checked in accordance with the Troubleshooting TM. Going to pull the starter and have it checked out by a local shop here cause that's the last link in the chain.