• Steel Soldiers now has a few new forums, read more about it at: New Munitions Forums!

  • Microsoft MSN, Live, Hotmail, Outlook email users may not be receiving emails. We are working to resolve this issue. Please add support@steelsoldiers.com to your trusted contacts.

M1078 Won't Start

cavetech

New member
116
2
0
Location
Lake City, FL
I have a nice M1078, but it often (usually) won't start. Sometimes I go to start it and it fires right up. Often it won't start. I flip the master power switch on and push the starter button and nothing happens except a faint click seemingly in the dashboard. The starter does not turn over.

My batteries are good. Battery and starter connections are good and clean.

It might start one time and run fine and the next time I try to start it, nothing but the faint click in the dashboard.

I am really stuck and I can't find any mechanic to even work on it.

Has anybody experienced this? What the heck do I even look for?

I want to make the parade in Perry, FL on the 28th very much, but I'm afraid I'll get stuck.

Thanks, Steve
 

NDT

Well-known member
Steel Soldiers Supporter
10,430
6,469
113
Location
Camp Wood/LC, TX
Thermal switch on starter bypassed? Connectors properly seated in Allison VIM and TCM? Fresh relays in appropriate locations in PDP?
 

cavetech

New member
116
2
0
Location
Lake City, FL
Thermal switch on starter bypassed? Connectors properly seated in Allison VIM and TCM? Fresh relays in appropriate locations in PDP?
I'm sorry, but I don't understand what you are suggesting. You are obviously knowledgeable about the 1078, but don't understand your abbreviations.

Thanks, Steve
 

NDT

Well-known member
Steel Soldiers Supporter
10,430
6,469
113
Location
Camp Wood/LC, TX
I'm sorry, but I don't understand what you are suggesting. You are obviously knowledgeable about the 1078, but don't understand your abbreviations.

Thanks, Steve
Thermal switch is where two very small white wires go on the starter motor. Cut them off and connect together if not already done. The Transmission Control Module (TCM) is the transmission brain, which has connectors that can come loose. The VIM is the Vehicle Interface Module which can also have loose connections. The TCM and VIM assure the transmission is in neutral prior to allowing the starter to operate. The PDP is the Power Distribution Panel, in front of your passenger seat, there are relays there which make the starter operate, which can be defective or have corroded contacts. Hope that helps. If all else fails, the starters on these trucks cause a lot of grief as well, but are expensive to replace. Good luck.
 

cavetech

New member
116
2
0
Location
Lake City, FL
Thermal switch is where two very small white wires go on the starter motor. Cut them off and connect together if not already done. The Transmission Control Module (TCM) is the transmission brain, which has connectors that can come loose. The VIM is the Vehicle Interface Module which can also have loose connections. The TCM and VIM assure the transmission is in neutral prior to allowing the starter to operate. The PDP is the Power Distribution Panel, in front of your passenger seat, there are relays there which make the starter operate, which can be defective or have corroded contacts. Hope that helps. If all else fails, the starters on these trucks cause a lot of grief as well, but are expensive to replace. Good luck.
This I understand and I thank you for the simplified explanation. I think I can do this. Tomorrow will be interesting.

Thanks, Steve
 

cavetech

New member
116
2
0
Location
Lake City, FL
I spoke with a National Guard mechanic who knows the truck. He suggested replacing two relays in the breaker panel on the dashboard. I'm looking for them to buy right now. They are K19 and K1.
 

Smike740

Member
Steel Soldiers Supporter
199
15
18
Location
Columbus, Ohio
I spoke with a National Guard mechanic who knows the truck. He suggested replacing two relays in the breaker panel on the dashboard. I'm looking for them to buy right now. They are K19 and K1.
I have the same issue occasional, maybe 1 out of every 20 times I get nothing when i push the start switch. Then it goes right back to working fine.

Please let us know if the relays solve your issue.
 

Moostang

New member
5
0
0
Location
Indiana
I see a lot of starter problems on the older trucks. The starter solenoids go bad often. Have someone hold the button down and tap on the solenoid. Also have seen water get inside and rust them up and cause intermittent problems. On a side note, I have seen several with loose bolts holding the nose cone on but they usually still start fine.
 

cavetech

New member
116
2
0
Location
Lake City, FL
I see a lot of starter problems on the older trucks. The starter solenoids go bad often. Have someone hold the button down and tap on the solenoid. Also have seen water get inside and rust them up and cause intermittent problems. On a side note, I have seen several with loose bolts holding the nose cone on but they usually still start fine.
Sounds like good information. Believe it or not I actually knew to try the trick to hold the starter button down while I tapped the starter and solenoid with a hammer. Unfortunately it didn't work.

I just put my new relays in the panel. I hope they solve the intermittent problem.

Thanks, Steve
 

cavetech

New member
116
2
0
Location
Lake City, FL
OK, I have more information. I have replaced the K19 and K1 24v relays. The truck has been in a good mood and was starting reliably. Yesterday it wouldn't start.

Today I discovered it will start in Drive (not neutral). After starting in Drive it will also start in Neutral. But, for how long I don't know. I've got to fix this truck for the Perry parade on the 28th. Now it starts repeatedly in Neutral. But, it may stop starting at any time now and I can't risk getting stranded.

When I press the transmission up and down arrow keys at the same time I get a code of d1. What does that mean?

Should I bypass the neutral transmission ecu relay? If so, how???

What is happening and how do I fix it?

Thanks, Steve
 

Rebuilder

Member
96
5
8
Location
Minnesota
OK, I have more information. I have replaced the K19 and K1 24v relays. The truck has been in a good mood and was starting reliably. Yesterday it wouldn't start.

Today I discovered it will start in Drive (not neutral). After starting in Drive it will also start in Neutral. But, for how long I don't know. I've got to fix this truck for the Perry parade on the 28th. Now it starts repeatedly in Neutral. But, it may stop starting at any time now and I can't risk getting stranded.

When I press the transmission up and down arrow keys at the same time I get a code of d1. What does that mean?

Should I bypass the neutral transmission ecu relay? If so, how???

What is happening and how do I fix it?

Thanks, Steve
This is what I had to do when I had issues with my starting circuit. Remove the K1 Starter Relay, turn the main switch on and check for 24volts at terminal 30. If you have 24 volts you can jump 30 to 87 and it should start the truck. Doing this bypasses all the other relays in the starting circuit. It doesn't solve your problem but if it works you'll know your starter is fine and you'll have a way to start your truck until you can fix the problem.
 

cavetech

New member
116
2
0
Location
Lake City, FL
This is what I had to do when I had issues with my starting circuit. Remove the K1 Starter Relay, turn the main switch on and check for 24volts at terminal 30. If you have 24 volts you can jump 30 to 87 and it should start the truck. Doing this bypasses all the other relays in the starting circuit. It doesn't solve your problem but if it works you'll know your starter is fine and you'll have a way to start your truck until you can fix the problem.
I have the breaker panel open. K1 is a relay I have replaced, but which leg is terminal 30? I see the sockets the relay legs plug into, but none of them are marked. I don't see anything marked 30. What have I misunderstood?

Sorry, Steve
 

Rebuilder

Member
96
5
8
Location
Minnesota
I have the breaker panel open. K1 is a relay I have replaced, but which leg is terminal 30? I see the sockets the relay legs plug into, but none of them are marked. I don't see anything marked 30. What have I misunderstood?

Sorry, Steve
The numbers are on the blade side of the relay. 30 is the top one and 87 is the bottom one. The electrical schematics are near the end of the TM m1078_TM 9-2320-365-20-2 . They're a bit intimidating at first but well worth the time to learn how to read them.

To clarify.... to start the truck this way you jump 30 to 87 and remove the jumper right when it starts.
 
Last edited:
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website like our supporting vendors. Their ads help keep Steel Soldiers going. Please consider disabling your ad blockers for the site. Thanks!

I've Disabled AdBlock
No Thanks