JOHN DEERE 110 TLB COMPLETE LIGHTING CIRCUIT DEAD

[trctr155]

Hello, I recently found and bought a 2003 110TLB from orig owner with 84 orig hours. Problem is all the lighting is dead,i.e., front/rear work lights,stop/brake,overhead beacon,turn,hazards,instrument cluster,etc. Per the manual, it shows the main lighting circuit runs through a 30a main fuse(F3). I removed the light switch(S9) and verified it functions(per the manual), I have 12v to the switch, once I turn the switch to any on position the voltage drops to 15v approx., and nothing comes on. In studying the wiring diagram, and the fact that everything isn't working I suspect the common ground that everything returns home on. Yet I stuck my probe into the ground wire side of on of the front headlights(from the pos side of my battery) and it lit up(verifying it made it to ground). Confusing.
Just wondering if anyone has every dealt with this same issue. Thanks in advance.

 

[Roadworthy]

Check the thirty amp fuse. Don't just look at it, test it with a meter. Sometimes they look good but the connection is poor internally.

 

[radios1]

I have 12v to the switch, once I turn the switch to any on position the voltage drops to 15v approx.,
Just wondering if anyone has every dealt with this same issue. Thanks in advance.

I don't see how that is possible!. the voltage climbs 3V just by turning the switch to an on position?.

 

[kennyd]

I don't see how that is possible!. the voltage climbs 3V just by turning the switch to an on position?.

My guess is he missed adding the decimal...so the voltage DROPS to 1.5 volts.

 

[Dave M7040]

This info may help

Dave M7040

 

[Dave M7040]

More pages

Dave M7040

 

[TerryR]

Sounds like there is a current leak (high-resistance short) in the wiring past the switch.

 

[trctr155]

My guess is he missed adding the decimal...so the voltage DROPS to 1.5 volts.

Yes, thanks Kenny you are correct. Voltage drops to 1.5v once switched on.
30a fuse is good and holding.
Thanks for the schematic Dave. Interesting thing is I get 12.65v at B on S9 with a voltage meter. Yet when I probe that same spot with a light meter(the type that lights the small bulb) it will not light up? It will light it up at the fuse however. Which leads me to think the bulb is pulling the V down, therefore my problem may be after the 30a fuse and before the switch(S9). I would like to isolate by disconnecting X23 and 24 harness connectors(tlb3) but from the view under the tractor it is very difficult to find. There is a ton of wiring on this machine most of which is cramped up inside.
Thanks for the thoughts guys, sure would like to solve this on my own. Hourly rates for electrical gremlins can get costly. This machine only has 84 org hours and is very clean so rust and corrosion looks to be at a minimum.

 

[fried1765]

Yes, thanks Kenny you are correct. Voltage drops to 1.5v once switched on.
30a fuse is good and holding.
Thanks for the schematic Dave. Interesting thing is I get 12.65v at B on S9 with a voltage meter. Yet when I probe that same spot with a light meter(the type that lights the small bulb) it will not light up? It will light it up at the fuse however. Which leads me to think the bulb is pulling the V down, therefore my problem may be after the 30a fuse and before the switch(S9). I would like to isolate by disconnecting X23 and 24 harness connectors(tlb3) but from the view under the tractor it is very difficult to find. There is a ton of wiring on this machine most of which is cramped up inside.
Thanks for the thoughts guys, sure would like to solve this on my own. Hourly rates for electrical gremlins can get costly. This machine only has 84 org hours and is very clean so rust and corrosion looks to be at a minimum.

If you are willing to say, how much did you give for it?

 

[Dave M7040]

Yes, thanks Kenny you are correct. Voltage drops to 1.5v once switched on.
30a fuse is good and holding.
Thanks for the schematic Dave. Interesting thing is I get 12.65v at B on S9 with a voltage meter. Yet when I probe that same spot with a light meter(the type that lights the small bulb) it will not light up? It will light it up at the fuse however. Which leads me to think the bulb is pulling the V down, therefore my problem may be after the 30a fuse and before the switch(S9). I would like to isolate by disconnecting X23 and 24 harness connectors(tlb3) but from the view under the tractor it is very difficult to find. There is a ton of wiring on this machine most of which is cramped up inside.
Thanks for the thoughts guys, sure would like to solve this on my own. Hourly rates for electrical gremlins can get costly. This machine only has 84 org hours and is very clean so rust and corrosion looks to be at a minimum.

Troubleshooting relying on voltage can be misleading. A modern voltmeter needs very little amperage to operate. In your case less amperage then even your test light.

While your light switch passes the WSM test, perhaps the problem is in the connector which plugs into the light switch.
A poor factory crimp perhaps.

I suggest you unplug the light switch connector and then using a length of wire, provide power to each of the light circuits it feeds.

Next, do the same thing with each lighting fuse. Provide power to the out side of the fuse to see what happens.

Also check fusible link as it is common to the circuits not working. Perhaps it has almost failed and is allowing a little voltage to trickle through

Dave M7040