M108 Starting issues

[jonfly673]

I cannot get my M108 to start. In the crank position i only hear the fuel pump kick on but no starter. I have replaced the battery and starter, still nothing. The interior panel comes alive in the first starter position and when I turn it to crank the panel stays up. After the new battery I did hear the bendix kick in once but now nothing. I also have checked and cleaned all safety switches and grounds I can find. The ground cable and hot have been bypassed to check them and still nothing. This is the second new battery and the old starter bench tested good but I am trying to eliminate any off the shelf failures. Any Ideas?

Jon

 

[1970cs]

Have you tried turning the key to the on position and then crossing the start lead to the + battery post on the starter? This will get you working if the starter and all of the work you have done is correct. Just make sure all sticks are in the neutral position or have someone in the seat with clutch pedal down.

Pat

 

[Tooljunkie]

Actually, leaving key off as a safety measure just to test starter wouldnt be a bad idea.
Jump battery + to small post on starter solenoid it should crank.
Cranks, then not battery or cables
No crank, then replace both cables and recheck battery.

 

[Tx Jim]

Is pto control in off position???

 

[85Hokie]

Did anything happen to "create" the no start?
You went out on day and it was dead?
or ........
is the bendix on the starter or built into starter?
when the starter was replaced was the original bendix used?
fuseable link?

to hear a click in the solenoid is eliminating a lot of other possibilities. And points to a battery, wiring, solenoid issue.

The new battery - sure it was at 100% charge? A new battery for any place, typically needs to be charged since it has been sitting on the shelf for weeks or months.

 

[jonfly673]

I am going out to check the starter switch in the way explained. I have cleaned and checked all contacts, safety switches, fuses and breakers. I am a little skittish about jumping + direct to starter.
I have already bypassed all cables by jumping the + and - straight from starter to battery with my 0 gauge cables. No Joy.

The initial starting problem began after a few weeks sitting and I would come to run it and the starter would only click once or twice and then nothing. After a few minutes on the charger or jumping it would start. I ran it hard a few weeks ago for a day and I lugged the engine so hard it died on me and it wouldn't start until I jumped it. The next morning I went to start it and nothing but one click. After that any key attempt produced only fuel pump and panel lights, no start noise. Since then the troubleshooting above insued.

Thank you for the help
Jon

 

[85Hokie]

I am going out to check the starter switch in the way explained. I have cleaned and checked all contacts, safety switches, fuses and breakers. I am a little skittish about jumping + direct to starter.
I have already bypassed all cables by jumping the + and - straight from starter to battery with my 0 gauge cables. No Joy.

The initial starting problem began after a few weeks sitting and I would come to run it and the starter would only click once or twice and then nothing. After a few minutes on the charger or jumping it would start. I ran it hard a few weeks ago for a day and I lugged the engine so hard it died on me and it wouldn't start until I jumped it. The next morning I went to start it and nothing but one click. After that any key attempt produced only fuel pump and panel lights, no start noise. Since then the troubleshooting above insued.

Thank you for the help


Jon

Based on what you are saying now, the problem is not related to the starter but the current getting TO the starter.

IF JUMPING helps, then the problem is the original battery and or connections.

It takes a hellva lot of amps to turn a diesel over - more so than a gas engine.

I would get a very new battery - or one that is known to have the correct CCA and place in the tractor.

This has nothing to do with starting - but you might have a charging problem too. Your battery might NOT be charging and thus causing the non start.

WHEN you get it running again, and you will, place a volt meter across the battery and tell me what you get .........something close to 14 volts or more at 1/2 to Full throttle is expected.

report back.

 

[North Idaho Wolfman]

When everyone it talking about "jumping the starter", they mean all battery cables are in there proper location on the starter and the battery and ground, you will use a small wire to jump from the large + connection on the starter to the very small solenoid connection on the starter.
How many small connections are there on your starter? Some have 2 and if swapped they will not work right as one is solenoid input to engage the starter and the other is solenoid output to the Fuel stop solenoid.

If jumping the starter get it running, then you could have a bad safety switch, bad key switch, bad wiring, bad starter relay (if equipped) or bad OPC timer (if equipped).

 

[jonfly673]

Just went out to the tractor. Jumped starter switch hot to start position. I could get the Bendix to extend every time this time but did not get the engine to turn over. This go around I had jumper cables hooked up from my Tahoe registering 14 1/2 volts. I checked and labeled all soldered positions on my starter switch they are all getting a current of 12 1/2 volts with battery power. It looks like I'm just not getting enough power to the starter to turn the engine over. Any suggestions?

To answer in above question yes the PTO is in the off position and the contacts clean

 

[jonfly673]

My problem was a safety neutral switch under the cab. It was intermittent and would allow current enough to the starter but not enough for an engine start. Thought those things either worked or didn't! I crawled under the cab and flinched all the wires and twisted the sensors they were attached to and then jumped the starter + to the solenoid and it kicked over. I am going to the farm tomorrow to pull the switch. Thank you for your replies.

Jon