1997JD 5300 electrical short in lights

[Xjdigger]

Hi, help with a very mysterious problem that I have days in searching.

Light circuit on 3rd position of switch has a bleed to ground .92 m ohm testing.
Turning the lights on the circuit heats up but does not blow 20 amp fuse.
The headlight switch is burnt on positive input and light output but switch still works to turn lights on.
Unplugged lights and wiring at light switch. and test yellow 114 wiring and it is shorted to ground ,92m on testing OHM.
Ground wire at light plug is 0.00 on OHM test
When I jump power to lighting using a 20 amp fuse, Wire heats up but does not blow fuse, with headlights plugged in or unplugged.
Voltage is consistent at switch input power and headlight plug

I have inspected all the wire that I could get to, removing all panels, fuse block, but cannot get to wiring behind motor to fire wall and behind the power steering column. I've discussed this with my John Deere service and parts and have found that there is a diode the Yellow 114 wire goes to but looking at wiring diagram there is no ground at this position.

I have exhausted all that I know what to do so far. has anyone run into a similar circumstance that could give me advice. My next trial will be running a hot wire directly to the lights because I have work to do but really want this to be right for the winter.

 

[beenthere]

I got a bit lost in the translation but sounds like you are looking for a short somewhere in the wiring.

I make up a "tester" from a 12v bulb and a blown fuse, so it plugs into the fuse socket. If there is a short, that bulb lights up.
Makes it much easier to push and pull and move wires around in hopes to find the one causing the problem. Or lift wires from devices or connectors for that one that causes the bulb to go out. Then the task of where to fix the problem is at least identified.

 

[JD5210]

Based on your description, it looks like the wiring for the 5x00 and 5x10 is the same or close, so I have attached the wiring diagram for 5x10. On the 5x10 the third position is dim headlights, tail light(s) and warning lights. These are estimates by me head lights take about 8 amps, warning lights 6 amps and tail light ? Also the instrument lights take a little.

Have you added anything?

Here is what the 5X10 manual, says about the diode -Current also flows through one diode of diode pack to instrument lights. Remaining diode blocks current from passing into high beam circuit-. Does it look like the high beams are on? If you add in high beams you are right up there in amps.

Could be the diode is bad. Have you tired pulling out the diode pack? On the 5X10 it is located under the left cowl, there are little black boxes it is the one closest to the engine. Looking at JD parts (wiring, harness rear), it looks like it is located in the same spot on your tractor. I had a problem on my tractor of the instrument lights not always working, tested each of the diodes in the pack several times and it test good, but it was not until I replaced the diode that I fixed the problem.

John Deere - Parts Catalog

 

[Xjdigger]

That is a good idea. I've been searching for a short in the wire by plugging 2 spades into the lamp socket and then attached an ohm meter to it then follow the wiring conduit tube and pulling wires out as I can or moving them pushing and pulling in hopes to find a change in the meter.

I don't understand the Diode that keeps lights on either hi or low as selected and whether that could be the source of the problem. But there is no ground shown to that circuit.

 

[Xjdigger]

Thanks, I've looked at that wiring diagram which was posted in another thread.

I had added lights on the loader when I bought the tractor new in 97. I've tested the system with and without the lights wired in and still have the short,

What I noticed in the wiring diagram is where is the light switch circuit which has orange wires for high and low beam.

Also I noticed that the circuit runs through dash lights and may be the source of .92 ohms to ground. I'm heading out to check.

If so what is the load that has melted my light switch and wiring? It is not the lights I added because it does the same plugged or unplugged. The test jumper wire still heats up pretty hot?

Thanks for your input.

 

[JD5210]

The most common function of a diode is to allow an electric current to pass in one direction (called the diode's forward direction) while blocking current in the opposite direction (the reverse direction). Thus, the diode can be thought of as an electronic version of a check valve.

If the diode goes bad it can allow circuit to pass in both directions, which could allow the high beams to be on at the same time as the dim beams. Since the head light has 2 beams in it. If like 5x10 there are 3 wire to the head light ground, yellow 114 for low and wht 119 for high.

 

[Xjdigger]

Thanks for some insight I realized my ohm testing on the yellow wire circuit was testing grounded items such as the dash lights. When I tested the wiring with the diode block removed there was no short in the wiring.

With the diode block removed the lights still worked from the light switch.
But only the circuit for the low beam. I had previously removed the #3 20 amp fuse to disable the flashing lights. The switch does not turn on the high beam in the high beam selector. The low beam and my installed loader arm lights come on either on high or low beam. Do not understand why.
The wiring gets hot without blowing the 20 amp fuse.

I'm still confused with the function of the wiring of the lighting circuit and what could be overheating the light switch. I probably need to do an amp test on the circuit but do not know how yet.

I have studied the wiring diagram posted and I do not see the wiring to the light switch.
The head lights are powered with a white, Yellow and black wiring.
Yellow and White wire goes to the Diode block and lights work either plugged or unplugged but only on the low beam circuit. And I disabled the flashing circuit by removing #3 fuse per another discussion thread.

The light switch has a live power input that is burnt but still operates. The wire casing and wire plug protector has been melted.

There are 2 Orange wires on the switch that power the headlights. I believe one may be the high beam

One of the orange wires I had spliced the loader arm lights is also scorched. Turning this light position on heats up the circuit with or without the installed lights. I disconnected the installed lights and it makes no difference on the overheating and these lights were installed in 1997 when I bought the tractor new.

This is what I have so far

 

[JD5210]

I do not know, why pulling the diode would cause the high beams and high beam indicator not to work. I will need to look at the wiring diagram more.

The orange wires out of the light switch 103 and 113 change colors and numbers after passing through the fuses (do not ask me why). 103 changes to gray 118 and 113 changes white 119

On the fuses, if you pull the 30 amp fuse (F7, 30-Amp: Horn, lights, turn signals) that feeds the light switch I think you will find that is the fuse that is getting hot and NOT the 20 amp. Here is a test to try, pull the 3 - 20 amp fuses for the turn signals, high beam and low beam. Then turn the light switch on if the light switch gets hot it is on the power input side and not the power output side. If the switch does not get hot, put the fuses back in one at a time.

Some meters only go up to 10 amps, so be careful you do not damage your meter.

On the wiring diagram look for fuse F7 near the top of diagram to the left this is the power to the light switch.

 

[Zebrafive]

My thought is the reason high beam and high beam indicator will not work with the diode pack removed is the switch contacts for high beam have failed. These bad contacts may be creating resistance heating up your wire.
If high beams and high beam indicator works with the diode pack installed, my guess is the diode pack is bad and the low is what is powering the high beam.
I would replace the light switch. If high and low come on together when in low beam position replace the diode pack. I would rewire the added loader lights thru a relay. They may have overloaded the light switch

 

[Xjdigger]

Thanks for the advice. I know that I have been very confused in understanding what my test were because they have made no sense. My experience is automotive in a Chevrolet dealership from 1968 to 1991.

My problem may center around the Diode which test shows a voltage of 8 and 9 volts on wire yellow #114 and white #119 in either 3rd position low beam and 4th position high beam but the 5th position low beam does not heat up. that is 1st- off, 2nd- Warning

The switch is burnt at power input with melted wire casing, protector sleeve and scorched spade. and the orange #113 that I have spliced in the lights on the loader arm. Light switch still works after leaning power input.

The loader arm lights probably over powered the switch since 1997 when installed.

Now the voltage on both yellow #114 and White #119 being 8.67/8.87 on each in low beam and 9.46/9.22 in high beam seems to be due to the diode switch being burnt out. This diode was an unknown factor early in my exploring of what was going on.

I'm going down to the shop and test this theory which makes complete sense after reading the valuable responses from you guys. I had no help from the John Deere Shop in getting a clue on what to look for. They are to far away to take the tractor to but I have bought plenty of parts and some implements but they were not forth coming to try and help with the exception of the parts guy. he did tell me that there was a diode in the system but did not know what the function was.

I have other parts on order that will be in next monday or could be in friday. Internet parts is quicker delivered to the door.

I'm going to the shop to confirm this and rewire all my auxiliary lights to another switch and power relay. Probably explore installing better high power led lights. Then I'll check my installed lights on my JD4100 compact.

I see how I can temporarily jump the wires for headlight and rear lights to go back to work until I get the new switch and diode. Hopefully I have my problem solved but still don't understand why there is so much heat build up when I can power all the lights from jumper wire without getting the hot wires.
and eliminate the switch