L4150 fuses and starting problem

darisb

New member

Equipment
L4150
Dec 25, 2015
3
0
0
Coos Bay, OR
I bought a 1988 L4150 about a month ago. It started fine when it was delivered. I went to start it the other day and the dash and idiot lights came on but I got nothing from the starter. I jumped power to the solenoid wire and it started an ran.

This morning I put a test light on it and got nothing to the solenoid wire when my wife turned the key. We noticed that there were fuses below the steering wheel. There is no cover, so I don't know what the proper fused amps are for each slot. One fuse broke when it came out. There is an empty slot, but I can't tell if there are connectors. Can someone post (or email me) a picture of the fuse panel or the diagram from the manual?

Also, can anyone offer some advice on what might be preventing power from being applied to the solenoid wire?

Thanks,
Daris
 

ctmike

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L 3750 DT with loader, brush mower, rear grader blade, box scraper, rear blower,
May 10, 2013
143
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Suffield, CT
There is also a red, fusible link wire up by the starter that could be burned.
I've been told that these tractors had issues with not allowing enough amperage through the key switch to activate the starter. My L3750, which is the same as yours, had an auxiliary starter button installed that bypassed the key switch and it works fine.
 

rbargeron

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L5450, L48, L3250, L345 never enough attachments
Jul 6, 2015
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western ma
With no voltage at the solenoid wire, a safety switch is likely open somewhere. On my L4150 when the red fusible link was bad the solenoid didn't work and the red dash lights didn't either.

Here's a pdf from the factory website showing a couple safety switches to check - on the parking brake and clutch. Good luck - Dick B.
 
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Russell King

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L185F, Modern Ag Competitor 4’ shredder, Rhino tiller, rear dirt scoop
Jun 17, 2012
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Austin, Texas
The clutch pedal has a safety switch. Was it pressed down and held down when starter switch (probably separate from key) was turned?


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Dave_eng

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Lifetime Member

Equipment
M7040, Nuffield 465
Oct 6, 2012
5,239
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Williamstown Ontario Canada
I agree with the previous two posters that you have an open safety switch.
Your pto may have one in addition to the two previously suggested.
Sometimes, to make tractors more resistant to being started and stolen, people leave the pto engaged and then the starter wont turn over.
Clutch and handbrake are possible ones but if you have a shuttle shift and it is not in neutral you cannot start the tractor.
You also likely have an "operator present" switch or seat switch which might be involved.
Dave M7040
 

darisb

New member

Equipment
L4150
Dec 25, 2015
3
0
0
Coos Bay, OR
I bought the service manual download and studied the wiring diagram. This past Sunday I tested the safety switch and it appears to be functioning properly. I found the wire coming from the switch, and got 12 volts when the key was turned to start. I plugged the wire into the safety switch, and put the probe on the wire coming out. I got 12 volt there also.

The wiring harness has been hacked up. There's a second of the harnesses sticking out from under the dash, near the safety switch. All of the wires have insulated spade connector on them.

The wire to the solenoid is white, and it should be black with a white stripe. I'm going to have to trace it from the switch back to the solenoid. Now that I know where things are and how they are routed, it should be a pretty easy fix. I just need to trace the wire back from the solenoid and find the break.

Thanks everyone.
 

Dave_eng

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Equipment
M7040, Nuffield 465
Oct 6, 2012
5,239
1,022
113
Williamstown Ontario Canada
My experience has been is that sometimes the safety switches have deteriorated to the point that they will pass a 12 volt test light or voltmeter signal but not pass enough current to activate the starter solenoid. At times manufacturers have provided a relay just before the solenoid with the hope that enough amps flow to activate the relay which in turn activates the starter solenoid.
Here are details on how to install a relay to help garden tractors start when voltage at starter solenoid is low due to safety switches being corroded. The principles are the same for larger machinery.

http://www.mytractorforum.com/234-a...18-starter-assist-relay-assembly-install.html
Dave M7040
 

darisb

New member

Equipment
L4150
Dec 25, 2015
3
0
0
Coos Bay, OR
There is a "old style" three post solenoid installed between the starter and the solenoid wire. I can put a jumper from battery cable to the small post that actuates the add-on solenoid and the 4150 start right up. Given that it seems like the add-on solenoid and the starter are working properly.

Again, someone has hacked up the wiring harness and installed a bunch of crimp on connectors. I'm really tempted see which harnesses are butchered and replace them all. For now I will double check the voltage at various points when I trace the solenoid wire back from the add-on solenoid to the safety switch.

I do appreciate all the advice and keep it in mind until I find the actual cause of the problem. Hopefully I'll find a little time this weekend. The good news is I've been able to use the tractor a couple time by turning the key to start and jumping the add-on solenoid, so I'm not completely dead in the water.
 
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