1995 520H

[Red520 9]

Hello All,

The 1995 520H I just purchased has a lighting issue. The lights and gauges do not work and I found that the 20 amp fuse was blown. I replaced it and the lights and gauges worked while I was adjusting the tranny drift with it running. Afterward I took it out to mow and the fuse blew when I started it. Later on I put a new fuse in and it blew again when I started it. The wiring shows 3 fuses but mine only has 2 and the other fuse plug ins are void of terminals. Has anyone had a similar problem like this? It sounds like it has a short but I thought someone may be able to point me in a direction instead of trying to test everything with my meter.   

[953 nut 51,511]

    I guess your first step would be to look at the wiring diagram in the manual and see what is protected by the 20 amp fuse and inspect them.

 

If you put a test light in the fuse holder (key on) it will light up when there is a load on the circuit. If a wire looks like it may be causing the problem and you find that the light goes out when you move it that is probably your short to ground.

[cleat 4,936]

Your machine should have 3 fuses. Maybe one is separate from the fuse block somewhere else.

 

I have mine all wired with a fuse down by the starter solenoid for the charge circuit to take that out of the 9 pin.

Later model 520 wire diagram.pdf

 

The late 80's 520's came that way.

Wheel horse 520H wire diagram.pdf

 

Cleat

 

[lynnmor 6,762]

You should have 3 fuses in the 4 position fuse block.  I added a fourth for a windshield wiper.  Hopefully you can still buy the blocks at AutoZone.  Those blocks are a bit troublesome.  Once you have that sorted out correctly, report back.

[Red520 9]

I was looking into the wiring situation yesterday and it looks like the one fuse block may have melted so they tied the wire from it into the other fuse. I put a 20 amp fuse in the open slot last evening and everything worked for a while then when I should the tractor off and restarted it the fuse blew again. I also noticed that the charging meter was pegged at 16volts. lather I looked down and it was at 12. I am going to pick up another fuse block and separate the wires back to individual fuses and see if that solves the issue.

[Red520 9]

Hello Again, So I changed out the fuse block and wired it as the diagram shows. When I started it all the gauges and lights worked fine until I shut it off to finish the job. When I started it the second time the fuse blew as I was starting it. I checked the voltage at the battery as it was running and I get a reading of 17.5 volts. So I removed the voltage regulator and cleaned all of its surfaces and the shroud underneath where it makes contact. I started it again and still got the same voltage reading of 17.5 volts. Sounds like the voltage regulator needs replaced and will that high voltage output cause that fuse to blow? The fuse is the one for the lights and the gauges.  

 

Edited October 10, 2016 by Red520
double post

[lynnmor 6,762]

Don't depend on the dash voltmeter, it might not be correct.  Some digital meters don't play well with these simple systems, so try another meter, preferably an analog type, and see if they read the same.  It's not likely that the high voltage is blowing fuses, but you should be burning out bulbs.  There are regulators on eBay for various prices, I don't know if the price determines quality.

[Red520 9]

 I went out and put my light tester across the fuse block terminals and it blew the bulb out. I put a 20 amp fuse in it and started it and everything worked. The voltage gauge was reading 12 volts at half speed and 16 at full speed. I did not have time to stay and restart it again but I will try it in a while.

[lynnmor 6,762]

18 hours ago, Red520 said:

 I went out and put my light tester across the fuse block terminals and it blew the bulb out. I put a 20 amp fuse in it and started it and everything worked. The voltage gauge was reading 12 volts at half speed and 16 at full speed. I did not have time to stay and restart it again but I will try it in a while.

If your "light tester" is the kind with batteries, yes you will burn out the bulb.  Again, check the voltage at the battery with a simple analog voltmeter, the kind with a needle.  It should read about 12.8 volts not running and a maximum of 14.5 volts running.

[Red520 9]

The battery measured 12.6 volts. When I started it again last evening it blew the fuse. After it was running I put another fuse in and as soon as I got on it the fuse had already blown. Could it possibly be the ignition switch that is causing the problem? I also found that the seat switch has been bypassed with a jumper but that doesn't seem to be an issue. I will be installing a new voltage regulator today but I don't feel that is causing the fuse to blow.

[Red520 9]

So I got a new voltage regulator and installed it. The voltage is correct now but the fuse still blows. I was looking at it yesterday for a few minutes and found a break in that wire below the hour meter. It had been rubbing somewhere and had some burn on it and it was down to a few strands. I cut the wire and spliced it with a butt connector. I put a new fuse in and went out mowing and it was good for about a half hour and it blew again. I notice that the terminals on the backs of the gauges are dirty so I will remove them this weekend and clean them. I will also remove the seat pan and battery to see if I can locate any more issue with the wires.     

[Red520 9]

Yesterday I replaced the taillights on the 520H and checked through some more of the wiring. I did not find any other issues. I mowed last nught for an hour or so and the gauges and lights were still working when I parked it????