M35A2 trouble shooting starter/electrical problem

[TruckGuy]

Hey guys. Looking for a little trouble shooting help...

Truck crank/ran/shut off fine the last time it was ran. Only a couple weeks ago. Will try to go through what happened.

1. I connected the short jumper wire on the batteries ( I disconnect the batteries between runs)
2. Turned on main switch, get power. Engine stop still pulled.
3. Pushed start button. Engine turns over maybe a rev. stops.
4. See smoke cumming from battery from battery compartment. Killed main power.
5. Run around to batteries and there's a puddle of lead where the terminal has melted.
6. Ok. this didn't register at the time. but when I push the jumper over (melted terminal remember), there was still an arc. Remember the main switch was off.

Ok... So I had had problems with these batteries keeping a charge so I thought this was a good time to get fresh batteries, clean the terminals/cables and start clean...

Got the batteries. Clean/install Try to start again.... with someone watching the battery side. Power...start button... about a revolution... stopped... smoke at battery terminal.... kill main switch... pull jumper cable (had it on with wing nuts) ... still see an arc....

Seems like maybe the starter solenoid is sticking and pulling major amps. But wouldn't that make the starter run constantly? Again, no problems or signs of problems the last time the truck was ran.

Any guidance on how to troubleshoot is appreciated...

 

[glassk]

Hey guys. Looking for a little trouble shooting help...

Truck crank/ran/shut off fine the last time it was ran. Only a couple weeks ago. Will try to go through what happened.

1. I connected the short jumper wire on the batteries ( I disconnect the batteries between runs)
2. Turned on main switch, get power. Engine stop still pulled.
3. Pushed start button. Engine turns over maybe a rev. stops.
4. See smoke cumming from battery from battery compartment. Killed main power.
5. Run around to batteries and there's a puddle of lead where the terminal has melted.
6. Ok. this didn't register at the time. but when I push the jumper over (melted terminal remember), there was still an arc. Remember the main switch was off.

Ok... So I had had problems with these batteries keeping a charge so I thought this was a good time to get fresh batteries, clean the terminals/cables and start clean...

Got the batteries. Clean/install Try to start again.... with someone watching the battery side. Power...start button... about a revolution... stopped... smoke at battery terminal.... kill main switch... pull jumper cable (had it on with wing nuts) ... still see an arc....

Seems like maybe the starter solenoid is sticking and pulling major amps. But wouldn't that make the starter run constantly? Again, no problems or signs of problems the last time the truck was ran.

Any guidance on how to troubleshoot is appreciated...

I would try turning the engine by hand , pull handle and socket , and then see if starter has shorted ,...

 

[DieselBob]

Taking a WAG it almost sounds like a hydro lock condition which could explain the

3. Pushed start button. Engine turns over maybe a rev. stops.

and as soon as the starter stalls it creates a dead short to ground and the weakest link gives up which includes lead battery terminals that melt at a relatively low temp considering the amount of current that is now flowing through it which might account for

4. See smoke cumming from battery from battery compartment. Killed main power.
5. Run around to batteries and there's a puddle of lead where the terminal has melted.

Does your truck have a intake flame heater or either injection ?

 

[TruckGuy]

Was thinking about trying to turn the engine over by hand. Can that be done from up top? Kinda muddy under the truck right now. How hard should it be to turn?

The truck has a flame heater..

Hydro lock may fit the bill. One other thing that may be a piece of the puzzle.... the first time it did it, I had turned the power switch on for maybe a minute or so before I pushed the start button. So the tank pump would have been pushing fuel to the engine. Maybe pushed fuel past a leak somewhere?

 

[Flyingvan911]

The trouble keeping a charge could be a number of things. If the regulator (on the back of the alternator) is going bad it can draw power from the battery when the truck is off. The main switch going bad can also do this.

I'm also having the exact same starting trouble with my deuce. Main switch on, low air buzzer comes on. Push the start button and engine doesn't turn over. The low air buzzer quiets down quite a bit indicating a lot of current draw. It almost seems like the batteries are low but they aren't. I can actually turn my engine using the radiator fan. I turn it backwards and the engine rotates without too much effort. (With the engine stop pulled ofcourse.)

 

[rustystud]

First, your using the correct size batteries ? and there connected for 24 volts ? After you verify that the engine will in fact turn over by hand, then I would check the starter and solenoid and relay. The relay is mounted on the engine block just above the starter. Also make sure your battery cables are OK. No rubbing through on the positive cable creating a short. No corrosion in the cable. You can see this at the connectors. There will be a greenish color on the cable. After you check all that, we'll try and figure out where to go from there.

 

[TruckGuy]

rustystud...

Batteries both old (not holding a charge, even when disconnected) and new are group size 65. 850 cranking amps (1000cca). connected in series (24V).

Cleaned connections and cable ends when installing today.

Will check cables for chafing. Is there enough room to turn the engine over from the topside? Turn the fan maybe?

What do I need to check when it comes to the solenoid and relay?

Thanks

 

[stb64]

Turning the fan works.
Or use a ratchet w/ socket on the alternator pulley to turn the engine. In both cases, push down on the V-belt with your thumb to keep it from slipping on the pulley.
Make sure the battery clamps are in good condition, and tight on the posts.

 

[Flyingvan911]

I just reconfirmed that mine isn't hydrolocked. Also the starter doesn't seem to be trying to turn the engine. There are no shorts in any of the wires. I hope this helps.

 

[Flyingvan911]

My preliminary guesses are either the bad post on the battery is not allowing enough power to turn the starter or the starter itself is bad. I am definetly drawing lots of current from the battery when the starter button is pushed. This suggest the starter relay works fine. The starter doesn't spin but not engage with tells me the starter is ether frozen or engaging but not turning. However when I press the starter button I do hear a loud clunk which suggest the solenoid is engaging the starter to the flywheel. There are no shorts and the engine doesn't rotate the tiniest bit. All of the electrical connections are clean and tight.

 

[Flyingvan911]

I hope this will help, TruckGuy. It turns out that bad terminal that I had fixed with solder last year was the problem. Ironicly I tested it by filling it with more solder. Now that I have confirmed the problem I'm going to buy a set of group 31 screw post batteries to replace these old ones.

The real cause though was one we have seen time and time again. The sin of deferred maintenance. I knew I should have replaced the batteries right after the first meltdown but the solder fix gave me a false sense of security.

 

[TruckGuy]

OK guys. Rain finely stopped. Didn't have much time, but I did climb up to see if I could turn the engine over....

I really didn't see a way to get a breaker bar/socket on to turn the engine over. But by hand I could grab the fan and put tension on the belts..... With my hand around the middle of the fan blade, I could only get a couple inches or so of rotation. So not much. But the travel that was there felt smooth. Was able to see the crank was rotating, but again not much. When it stopped in either direction. It felt solid, not metal hitting metal, but good and solid. Rocked it back and forth, stopped in the same place.

 

[maa45069]

So what ended up happening? This would be helpful for newbies like me who changed all battery terminals put brand new batteries and has power to starter verified by multimeter 26v. Pretty similar to your situation

 

[TruckGuy]

Well.... I got some good advice from others here and I did need new batteries....

But it turned out to just be a bone head newbie mistake.... The truck had been setting in that spot for months. With the rain and mud it had pretty much attached itself to the ground.

So much so that I never even felt the truck try to move even thou I had been trying to start the truck while it was in 5th gear!!!

I had moved the shifter when I was painting in the cab.

Put it in neutral... fired off like normal. From what I gathered if the starter can't rotate, things can basically go to a dead short. At 24V, somethings going to go. Luckily it was just the lead battery terminal, no damage to any wiring. Live and learn.

 

[rustystud]

Well.... I got some good advice from others here and I did need new batteries....

But it turned out to just be a bone head newbie mistake.... The truck had been setting in that spot for months. With the rain and mud it had pretty much attached itself to the ground.

So much so that I never even felt the truck try to move even thou I had been trying to start the truck while it was in 5th gear!!!

I had moved the shifter when I was painting in the cab.

Put it in neutral... fired off like normal. From what I gathered if the starter can't rotate, things can basically go to a dead short. At 24V, somethings going to go. Luckily it was just the lead battery terminal, no damage to any wiring. Live and learn.

After awhile you will automatically reach for the shift lever and give it a shake before starting the engine.

 

[TruckGuy]

That's true Rusty. Sit in the set, drop the clutch pedal, check the gear shifter. All things you do without even thinking about it. But, that day I wasn't planning on driving the truck, just let it run for awhile. So I just reached in and pushed the start button. I never felt the truck try to move. My mind went straight to trying to troubleshoot a starter problem.

Part of me felt like an a$$ when I saw what it was, the other part was just glad there was nothing wrong with the truck. Had a good laugh and moved on.

But I did learn a good bit about the truck and spent time in the TMs, so not all bad.

 

[Welder1]

Most of us have made bone head mistakes but we just don't admit it. I tried for hours to install a fan clutch on my F450 Super Duty only to realize it was left hand thread. I pulled the old one off so I knew it was just didn't connect when I tried to install the new one. I felt really stupid for a minute. We all have done things like this.

 

[maa45069]

Thanks for the update lol I'll keep reading

 

[Jeff Nelson]

Well, just note that I have *never* done anything like that (today). The day isn't over yet, however. Wait! I do have an ex, so there is that one mistake..... ��