Electrical problem

[Mariongard]

Hey there
I have a 1987 L2550 GST (original owner) that I always have to jump the battery to start. Ran fine last week and went to start the other day and completely dead- tail light works but no dash lights etc. Fuses all good, clutch safety switch ok; can jump battery cable on starter to solenoid but starter only spins, will not engage.
Cleaned out big mouse nest bit can’t find any chewed wires.
Dealer says look for slow burn fuse but can’t find it.
Maybe 2 issues here as no voltage to dash and key switch and starter issue?
Any thoughts?
Thank you on advance

 

[Henro]

What do you mean when you say you jumped the battery and it starts? Do you mean putting cables from another battery onto the existing battery terminals?

Do you also mean that if you jump from the large terminal on the starter to the smaller terminal, the starter spins but doe not engage?

if so, sounds like time to replace the battery.

Troubleshooting with a voltmeter would be wise.

 

[i7win7]

Dealer says look for slow burn fuse but can’t find it.

Locate fuse panel, fuses are probably 15A or smaller - that means the largest wire on fuse block is the feed wire. Trace it to the "master fuse" looking for a plug in connector with a loop of wire

can jump battery cable on starter to solenoid but starter only spins, will not engage.

The gear on the starter could be bad or the flywheel could have a bad spot. can you use a socket/breaker bar on crankshaft to turn it a few degrees? You may have to pull starter - in olden days auto electrical shops could replace bendix gear.

Normally would recommend cleaning battery cables on both ends - If starter spins (assuming starter needs over 40A) battery cables and connections probably ok.

 

[Mariongard]

What do you mean when you say you jumped the battery and it starts? Do you mean putting cables from another battery onto the existing battery terminals?

Do you also mean that if you jump from the large terminal on the starter to the smaller terminal, the starter spins but doe not engage?

if so, sounds like time to replace the battery.

Troubleshooting with a voltmeter would be wise.

Battery never holds a charge so always use a jump box to start it.
Now everything is 100% dead even with jump box.
Yes jump from large terminal on starter to solenoid only spins starter, with jump box on battery.
Yes am checking with voltmeter too

 

[wgator]

When the battery box jumper don't work that usually indicates a shorted/dead cell in the tractor battery.

 

[BruceP]

I troubleshoot vehicle electrical issues several times a week.

It is not clear to me what you are "jumping" to make the starter spin.

If you jump DIRECTLY to starter... it is expected to spin and not engage engine.

To spin the engine, you need to jump +12v to the BENDIX SOLENOID (bolted to starter motor). It is this solenoid which pushes the gears into meshing AND spins the starter at the same time.

Now - to shoot your problem.... use voltmeter with black lead on battery minus.
Put red lead on the small connector on the bendix solenoid.
Turn key to start engine.
*) If see +12v, then the bendix is not working.
*) if NOT +12v - problem is NOT bendix/starter. (problem is before the starter in wiring)

Let us know what your result is and we can help shoot this further.

 

[Dave_eng]

Battery never holds a charge so always use a jump box to start it.
Now everything is 100% dead even with jump box.
Yes jump from large terminal on starter to solenoid only spins starter, with jump box on battery.
Yes am checking with voltmeter too

Your tractor has a 40 amp fusible link located near the starter. A fusible link is like a fuse. Blow it and all circuits are dead.

I suspect if you are jumping the starter and it just spins you are not jumping the proper terminals

Dave

 

[Mariongard]

I troubleshoot vehicle electrical issues several times a week.

It is not clear to me what you are "jumping" to make the starter spin.

If you jump DIRECTLY to starter... it is expected to spin and not engage engine.

To spin the engine, you need to jump +12v to the BENDIX SOLENOID (bolted to starter motor). It is this solenoid which pushes the gears into meshing AND spins the starter at the same time.

Now - to shoot your problem.... use voltmeter with black lead on battery minus.
Put red lead on the small connector on the bendix solenoid.
Turn key to start engine.
*) If see +12v, then the bendix is not working.
*) if NOT +12v - problem is NOT bendix/starter. (problem is before the starter in wiring)

Let us know what your result is and we can help shoot this further.
I have battery jump box direct to tractor battery and use a short jumper wire from terminal on starter from battery to terminal on solenoid attached to starter. Starter with t engage and only spins. Maybe not enough voltage with little jumper wire?QUOTE]

 

[Mariongard]

Your tractor has a 40 amp fusible link located near the starter. A fusible link is like a fuse. Blow it and all circuits are dead.

View attachment 48164

View attachment 48165

I suspect if you are jumping the starter and it just spins you are not jumping the proper terminals

View attachment 48166

Dave

Thank you Dave for the picture- yes I am jumping wrong terminals.
Will check and fusible link tomorrow. What would cause fusible link to blow?

 

[i7win7]

What would cause fusible link to blow?

You may have blown link while trying to jump start it

 

[Mariongard]

You may have blown link while trying to jump start it
Inters

You may have blown link while trying to jump start it

Interesting. Battery always goes down with very limited use. Even with battery disconnect switch won’t hold charge and not always near outlet to run trickle charger

 

[Dave_eng]

Thank you Dave for the picture- yes I am jumping wrong terminals.
Will check and fusible link tomorrow. What would cause fusible link to blow?

The link may not be blown but perhaps the connections surrounding it are so poor that there is no power going to the key switch.

Just to be certain you understand about these links. The loop of wire is not just any old wire but rather a small diameter wire surrounded by an insulation which will char but stay in place after the small wire burns through. The idea of the special insulation is to prevent the power end of the burned through wire from shorting against anything. Newer tractors utilize a SLOW BLOW fuse in the same location. The slow blow concept is for a fuse which can stand a momentary overload without blowing. The fusible link is just the old version of the same design need.

Continuing to jump the battery and challenge the charging system with a weak battery will lead to more and expensive problems.

Auto wreckers sell used but good batteries for a lot less $ than a new one.

Dave

 

[Mariongard]

The link may not be blown but perhaps the connections surrounding it are so poor that there is no power going to the key switch.

Just to be certain you understand about these links. The loop of wire is not just any old wire but rather a small diameter wire surrounded by an insulation which will char but stay in place after the small wire burns through. The idea of the special insulation is to prevent the power end of the burned through wire from shorting against anything. Newer tractors utilize a SLOW BLOW fuse in the same location. The slow blow concept is for a fuse which can stand a momentary overload without blowing. The fusible link is just the old version of the same design need.

Continuing to jump the battery and challenge the charging system with a weak battery will lead to more and expensive problems.

Auto wreckers sell used but good batteries for a lot less $ than a new one.

Dave
Thank you for the through explanation Dave[. Would I be better off replacing the battery and installing a trickle charger? Tractor only gets used a few times a year now.
Or take the battery out and keep it on a trickle charger?

 

[Dave_eng]

Batteries start to degrade when manufactured. Sitting in the tractor or in a shop makes little difference,

Buy a better quality trickle charger and leave it installed. A cheap charger can boil a battery dry over time..

You will be more likely to use the tractor if it is ready to go.

Dave

 

[Mariongard]

[/] looks like a fuse looking from the back but has continuity so not sure if I need to look elsewhere? Thank

 

[Dave_eng]

That is a part of the old technology voltage regulator which is part of the charging system. It is actually a resistor.

Dave

 

[Mariongard]

Batteries start to degrade when manufactured. Sitting in the tractor or in a shop makes little difference,

Buy a better quality trickle charger and leave it installed. A cheap charger can boil a battery dry over time..

You will be more likely to use the tractor if it is ready to go.

Dave
Thank you everyone for all your guidance. Turns out it was a bad connection either in the clutch safety switch and/or ignition switch. Cleaned everything up and secured all connections. Fired right up!
Now I can finish grading so we can build another greenhouse.

 

[Mariongard]

Thank you everyone for all your guidance. Turns out it was a bad connection in the clutch safety switch and/or ignition switch. Cleaned everything up and secured all the connections and it fired right up. Now I can finish grading so we can build another greenhouse.