• 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.

 

M35A2 Wont Crank After Battery Terminal Melted

78703TX

New member
19
0
1
Location
Austin, TX
I've read about 10 posts so far about starters failing but haven't found a similar cause as mine so figured I would post it.

I recently got my first deuce and have been learning everything I can about it. I've been through a solid year of getting everything perfect on a surplus humvee so not a total newb but definitely have never had anything this massive before. When I got the deuce a few months ago everything seemed to work fine. I drove it about 2 hours to the south Texas ranch property where it now lives and it ran like a top. After a few weeks it wouldn't start and found I had dead batteries. They were somewhat worn so I figured I'd replace them anyway because getting stuck miles from the cabin while thermal hunting for hogs can result in a poor night's rest. As I replaced the batteries I figured I might as well throw in a cutoff switch so when it's parked for weeks at a time I wouldnt have to worry about a parasitic draw. Me, not thinking about the massive draw on 2 group 65 batteries decided to buy the cheap plastic battery disconnect and extra terminal connection from autozone. Big mistake. As I was driving home from a hunt last week the headlights started flickering, followed by tons of electrical smoke. I pulled over as quickly as I could and killed the engine. Popped the hood and there looked to be smoke coming out of the massive starter motor. I opened the battery box and sure enough the negative terminal in the wire linking the 2 batteries along with the cheap switch were both sizzling. I'll skip past the part where I had to call a giant wrecker in from 3 towns over and paid through the nose.

I came back today with 4 new "military spec" battery terminals and new 2/0 cables to replace the ones effected in the meltdown. Got everything hooked back up and everything- lights, gauges all work. When I go to crank it (mine has a keyed ignition) the gauges move and I hear a clunk noise over the sound of air buzzer, but nothing even begins to crank. I have read there's a way to cross the posts on the starter with 2 screwdrivers, prybars or whatever to test it but I'm not sure which 2 posts to use and I don't want to fry anything further. Can anyone verify this? I unfortunately do not have a voltmeter with me but want to try something to test the starter. Judging by the smoke coming out of the starter when the battery terminal fried, I'm assuming that will be my issue. But I want to be sure before pulling it out. The wiring between the battery hot terminal and the solenoid looks fine so I would wonder how so enough juice got to the starter to fry it without burning up the wire..does anyone have any ideas on that?

Thank you for reading and I look forward to hearing from yall.

PS I found the original reason the batteries were dying was because my fan belt was so worn it wasn't turning the alternator. That has been fixed and the batteries have been showing full charge since.
 

sandcobra164

Well-known member
2,999
287
83
Location
Leesburg, GA
Sir,
Have you tested / charged the batteries since this incident? My deuce would do the same thing whenever the batteries were low on charge. If I had somewhere to go right away I'd keep bumping the starter button and most of the time it'd spin the engine over and off I'd go. If I had the time, I'd pull the batteries out and charge them.
 

glcaines

Well-known member
Steel Soldiers Supporter
3,834
2,393
113
Location
Hiawassee, Georgia
Make sure the battery terminals and posts are clean and tight. Definitely charge the batteries fully before doing anything else. If you don't have a 24V charger, you can charge each battery separately. Don't try to short across any terminals unless you are absolutely familiar with the wiring and where to short and wait until the batteries are fully charged. The procedure is to short across the starter relay terminals. I've attached a schematic for your use.
 

Attachments

Scar59

Active member
Steel Soldiers Supporter
2,811
41
38
Location
Mt. Eden, KY
Smoke from the starter leads to a fried solinoid. That may be the thunk you're hearing. Time to pull the starter and bench check it.
 

DeadParrot

Active member
213
46
28
Location
oklahoma city, ok
Don't overlook the possibility that the meltdown happened because the starter/solenoid stuck on or otherwise developed an electrical fault and burned up the wiring.
 

dmetalmiki

Well-known member
5,523
2,025
113
Location
London England
Don't overlook the possibility that the meltdown happened because the starter/solenoid stuck on or otherwise developed an electrical fault and burned up the wiring.
That, Is going to be the problem, An isolator switch would not cause that.
A starter motor "Powering your truck!" up the highway would.
 

78703TX

New member
19
0
1
Location
Austin, TX
Thanks for all the responses so far guys. Yall definitely got me on the right track.

After sandcobra's suggestion I went ahead and threw the spare batteries in but did not make any difference: I still had all gauges/lights/air buzzer going strong but when I turned the key got nothing more than a "thunk" noise.

I went through the schematic Gary sent (much appreciated Gary!). From that, and after buying a new voltmeter to keep at the ranch, I was able to determine several things:

-The Thunk noise seems to be coming from the Magnetic Start Relay.
-I have full 24V at Starter Solenoid Post #2 full time.
-I have full 24V at Starter Solenoid Post #1 when the key is turned.
-I get 0.1V at Post #3/Starter Motor when the key is turned.

Does this sound like a shot solenoid? I was able to get the solenoid off but did not have a 15/16 box wrench to take the starter motor off. Is there an easy way to bench test the Solenoid?

Would it make sense that the solenoid fried as a result of the cable meltdown or does this sound more like the solenoid got stuck open as deadparrot suggested which led to the cheap terminal/battery cutoff burning up due to them being the weak link? Do yall think there is any hope that my starter motor is actually still functioning?
 

78703TX

New member
19
0
1
Location
Austin, TX
For reference, here are some pics of my battery box as it sits now. I got a 300 Amp constant / 2000 Amp intermittent battery cutoff switch from JEGS and ran it into the cab behind the passenger seat. It looks like a well built switch that wont melt or break off in one's hand like the autozone special.

I had some new cables made by BestBoatWire.com which came out great and were at my door 3 days after ordering (I still need to order a new battery cutoff to battery neg link and a new battery pos to starter link). I connected these to new Fastronix terminals from amazon. Can anyone tell me how long the stock Battery Positive to Starter cable is and what size holes the connectors use?

IMG_20190217_1418403.jpgIMG_20190217_1418503.jpgIMG_20190217_1428421.jpg
 

78703TX

New member
19
0
1
Location
Austin, TX
Okay then.

I went ahead and ordered a new starter motor (NSN 2920-00-999-6216). After spending all day yesterday reading up on it going through TM's and trying to be for sure..I'm merely hoping this is the correct model for my LDT465 motor. Will report back once I get it installed.

The main cable that connects battery positive to starter is 4'10" long with a 3/8" connector at the battery and a 1/2" connector at the starter post in case anyone needs this in the future.
 

78703TX

New member
19
0
1
Location
Austin, TX
Just to update everyone, I got the new starter/solenoid in yesterday and it fired right up. Those 15/16 nuts holding it on are a real bitch to get to!

It looks like as suggested by Scar59, deadparrot and demtalmiki my solenoid must have stuck open and kept the full current going to the starter which caused it and the cutoff switch & battery cable to burn up. I plan on taking the starter apart to see what's going on inside once I have a few extra minutes.

Is there anything else I need to be worried about or was this problem most likely caused by the solenoid? Is there further checking I can do on my relay or ignition switch?
 
Last edited:

Scar59

Active member
Steel Soldiers Supporter
2,811
41
38
Location
Mt. Eden, KY
Good fix, disect the solenoid, you'll find the contacts welded/burned. As for the start switch and relay, they are part of the control voltage. Should not have been affected. If they are working now, just monitor their reliability. Maybe source a couple spares for the shelf. Check all the connections again for proper tightness.
 

78703TX

New member
19
0
1
Location
Austin, TX
Thanks for the advice! I will make sure to check all connections and volt test the ignition switch and relay to be sure everything is engaging/disengaging at the right times.
 

DeadParrot

Active member
213
46
28
Location
oklahoma city, ok
Might consider running a wire from the switched side of the starter to an indicator in the cab. That way you will know if the starter is still powered after start. Likely need to be a wide voltage LED as you probably don't have full volts when the starter is engaged. It could also be a troubleshoot aid in a no start is it would tell you the starter was getting power during a start attempt.
 

glcaines

Well-known member
Steel Soldiers Supporter
3,834
2,393
113
Location
Hiawassee, Georgia
As others have stated, it is most likely that your starter relay stuck closed and caused the problem. However, since you have stated that you have installed a key activated starter switch and don't use the OEM starter button, this is also a potential cause. Is the key switch you are using rated for 24 VDC? It is also possible that this key switch is failing and continued to supply 24 VDC to the starter relay. I would recommend checking this switch. This was an expensive fix and you don't want a repeat.
 

78703TX

New member
19
0
1
Location
Austin, TX
Great advice Gary. The keyed ignition switch definitely feels pretty spongy and cheap. The previous owner left the old push button in the glove box so I'll go ahead and switch back to that to eliminate the possibility of a $10 part burning up another $350 starter.

DeadParrot I like your thinking there. Do you think something like this would work?

https://www.amazon.com/Alpinetech-M...ight+24v&qid=1551208203&s=gateway&sr=8-8&th=1
 
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