1980 C-85 WheelHorse blowing fuse

[Henry Black 3]

Every time I try to start the tractor up it blows the 20 amp inline fuse from the starter solenoid. Any ideas on where to start. Thanks Henry

[maxiblue 352]

Welcome to RED SQUARE

[shallowwatersailor 3,213]

The first thing is to go through all of your electrical connections. See if a wire has worn the insulation away and is grounding. Also, the Black Hood tractors (C-85 to C-175, 1980-84) have a shaker-plate engine mount that required an additional ground wire to the frame. I have seen one of the lugs missing twice on that series tractors. It then requires the ground to find a different path.

 

 

Edited February 22, 2017 by shallowwatersailor

[SylvanLakeWH 26,273]

 and  ...

 

Check your grounds and tighten everything up...I love the blackheads, but the shaker mount does shake!!!

[953 nut 56,342]

     Rather than continuing to buy and blow fuses you can put a test light across the fuse holder and it will light up when there is short that would have blown the fuse. Disconnect the small wire going to the solenoid before doing this test as it would also light the test lamp. This wiring diagram should be helpful.

 

[Henry Black 3]

I see in the diagram that it is supposed to be a 25 amp fuse. It has a 20 amp fuse in it now that is blown. Do you think I need a 25 amp one instead. I'm not sure when the 20 amp was installed in it. It was in it when I got the tractor. Thanks for all your help.

[953 nut 56,342]

Presuming it was functioning properly for some time with a twenty amp fuse I don't think you will have any better results with a twenty five. Once you have resolved the problem you might want to use a twenty five. First you need to look at all of the wires in the path, make sure none are making contact with the frame or other metal. 

[Henry Black 3]

I will check out the wiring this weekend if I get a chance and if not then I will check it next week. I will keep everyone informed on my progress. Thanks

[kriggy 2]

You have a short, My C-175 was at the safety switch at the clutch. the wire fell off and touched the frame and it kept blowing the fuse as well. check all the wiring at this point, As this will save you time down the road. GOOD LUCK....Black Hoods Rule C-125 / C-175 1982's

[Jayzauto 89]

Using a light in place of the fuse is a great test, as it will limit the amount of current that can go through the circuit.  I use an old square headlight, such as H4656.  It will light is on (With key on), short is present. If light is off (Key on), short not present.  It's blowing a 20a fuse, so it's substantial.  Look for chafed wiring, WITHOUT disturbing the harness.  Nothing more frustrating than "Fixing" it, with out knowing what "Fixed" it.  AND it will come back, away from the tools, in the middle of a job.  Next after a visual inspection, Start disconnecting the loads (lights, solenoids), one at a time, then plugging them back in. When the headlight goes out, that item Is the short.  Using the correct wiring diagram for the machine is critical to your diagnosis. 

 

GLuck, Jay

Using a light in place of the fuse is a great test, as it will limit the amount of current that can go through the circuit.  I use an old square headlight, such as H4656.  It will light is on (With key on), short is present. If light is off (Key on), short not present.  It's blowing a 20a fuse, so it's substantial.  Look for chafed wiring, WITHOUT disturbing the harness.  Nothing more frustrating than "Fixing" it, with out knowing what "Fixed" it.  AND it will come back, away from the tools, in the middle of a job.  Next after a visual inspection, Start disconnecting the loads (lights, solenoids), one at a time, then plugging them back in. When the headlight goes out, that item Is the short.  Using the correct wiring diagram for the machine is critical to your diagnosis. 

 

GLuck, Jay

[Henry Black 3]

I have checked the wires and can't find a short, however it did crank up and run for about 15 minutes. Then it stopped. When I went to check the fuse, the fuse holder was so hot it burned my fingers. The fuse wasn't blown but the solder was melted out of it. The wire was really hot. I thought the wire should be cool to the touch at the fuse. Thanks for info

[Jayzauto 89]

That short is still there, and that fuse and holder is junk.  Definitely install a new fuse holder and try the headlight idea.  More "Burning" WILL occur.  Once the "Magic Smoke" comes out of electrical components, it's time to find out the cause, before that harness is a pile of rubble.  You can even use an old tail light bulb and socket as your test light.  Light on (with ignition on) and the short is present.  Bigger Test Lights will allow slightly more current without doing any more damage.  TIP: with the ignition on, and Test Light installed across the remains of your fuse holder, will also allow the offending circuit or component to generate heat that you can feel around with your hands.  If you have an older style magnetic compass, running that over the wiring harness may show where the short is also.  That needle will stand dead still when it is over the shorted component.

 

  ONE other quick tip if using the compass diagnostic method for you that were boy scouts, while moving the compass along the harness, the needle will tend to point towards the location of problem, stand still above the short and move backwards if you go past the issue.  Sounds tricky, but it's a simple, yet effective, although crude method if you only chase a short once or twice in the life of your tractor. 

 

GLuck, Jay

Edited February 26, 2017 by Jayzauto

[Henry Black 3]

I am going to try and check wires this afternoon. I did notice yesterday that the ammeter is pegged out on the right side while it is turned off. didn't remember that before but then again I really haven't noticed it before.

[Jayzauto 89]

GMorning H/B, THAT shouldn't happen.  Ammeter should be centered, indicating no electron flow when the key is off.  I believe that "Pegged far Right" indicates a full charge scenario??  Seems unlikely, since the machine should NOT be running at that point.  Good idea to watch the needle from key off to start, then run and track it's progress.  Should start off in center, show discharge during crank, charge during startup, slowly returning to center as alt/gen recharges battery.  

 

GLuck, Jay

[Henry Black 3]

That's what I thought too Jay. I will watch it and see what it does next time. I'm pretty sure it usually sits in the middle when it isn't running. I will keep everyone informed.

[Henry Black 3]

A couple more things to add first I found a break in the insulation in the wire going to fuse plug itself. It was black like it might have been hot at one time or another. Second the fuse holder started sparking when I started the tractor up. The fuse holder felt loose to me and when i shook it the tractor started dieing out. I'm not sure if a loose fuse would get hot or not. I did realize though that the fuses weren't blowing like they were grounded but the solder had melted in them. I also have a bad ammeter that is stuck on 15 on the + side of it. The needle is stuck i believe. Shaking it didn't help move it. I will add more info when i get the rest of the wires checked out.

Edited March 3, 2017 by Henry Black

[Jayzauto 89]

Using a light in place of the fuse is a great test, as it will limit the amount of current that can go through the circuit.  I use an old square headlight, such as H4656.  It will light is on (With key on), short is present. If light is off (Key on), short not present.  It's blowing a 20a fuse, so it's substantial.  Look for chafed wiring, WITHOUT disturbing the harness.  Nothing more frustrating than "Fixing" it, with out knowing what "Fixed" it.  AND it will come back, away from the tools, in the middle of a job.  Next after a visual inspection, Start disconnecting the loads (lights, solenoids), one at a time, then plugging them back in. When the headlight goes out, that item Is the short.  Using the correct wiring diagram for the machine is critical to your diagnosis. 

 

GLuck, Jay

Sorry, previous post must have been on the "Clip Board",  FIRST.....Ammeter may NOT be stuck....Disconnect it first, it may be reading accurately and showing a problem,  Unplug one side and it SHOULD return to 0.  If not, it is indeed no good.  DEFINITELY replace the fuse holder!!!  Poor connections will cause heat and engine cutting out.  That fuse is the protection for the rest of the system and it is MUCH cheaper and easier to replace than a wiring harness or ANY component.  Word of caution:  Disconnect battery before disconnecting the ammeter, then connect the battery to observe ammeter operation.  Same goes for fuse holder.   Once those 2 things have been verified and/or replaced, it will be safe to continue.  IDK if keeping it OEM is a consideration to you (I personally am a purist), but if not, now is a good time to swap the fuse holder for a newer style blade type (ATC) fuse and holder, that can be mounted to a secure easy to reach spot on the tractor. 

 

GLuck, Jay.

[Henry Black 3]

I disconnected the Battery and took the wires off of the ammeter and it stays on 15. tapping on it made it move a tad but that is all. I guess i better replace it. The fuse holder will be replaced this weekend. I will keep it as close to original as I can. Thanks for your help/

[Henry Black 3]

I finally had time to tinker with it again. I followed all of the wires and can't find any that are shorted. While it was running I started feeling wires to see which ones were getting hot. The orange wire coming from the ignition switch was getting the warmest. the red one was starting to feel hot too. I did notice that the Ammeter was running around 12 amps while it was running at about 2/3 throttle. I'm not sure what it is supposed to be running because the old ammeter was pegged all the way to the right. Any ideas on what to check next. Thanks Henry

 

 

 

 

 

 

[pfrederi 18,071]

The orange and red wires got warm because they charging system was running at 80% of it capacity for it sounds like an extended time.  Is your battery dying??  12 amp charge should drop off with in a couple minutes if the battery is OK  Normal cranking wouldn't drain the battery that much.

 

If the battery is good and the regulator working properly the ammeter should read very close to zero after a couple of minutes.

[Henry Black 3]

ok I will charge the battery and try it again. I don't believe the battery is going bad but it has been setting up for a while so it may be weak.. I will keep you informed until we figure this out. How do I check to see if the regulator is working properly. Thanks

Edited March 22, 2017 by Henry Black

[Tuneup 1,433]

I don't remember reading how long you've had this tractor. Did you just get it? Wondering because I've seen my share of rigging. There are also many kinds of ignition switch configurations and a dead short may result from an improper one - a Sears LT4000 I'm working on is a case in point. If you don't know what you have, you'll have to trace each wire and verify the switch is correct. Measure ohms to ground on each as well. My C-125 had plenty of over stressed wires and an open ammeter. A complete rewire wasn't much of an effort but desperately needed.

[pfrederi 18,071]

[Henry Black 3]

I just took ownership of this tractor. I got it because it was blowing fuses. That is what I was told anyway. When I got it running it wasn't blowing fuses it was melting the solder out of the fuses. That's when I started checking wires and found the ones that are heating up. I replaced the ammeter and when the engine is running about 2/3 throttle it goes up to about 12 amps and when it is running near idle it was 6 amps. Do I have a 15 amp charging system? I think I do since it is going up to 12 amps.  Thanks for all your help.

Edited March 22, 2017 by Henry Black

[gwest_ca-(File Mod) 11,148]

Should be a 15 amp stator.

Make sure the body of the voltage regulator has a good ground to the battery (-). With age enough corrosion of the chassis metal between the regulator and battery ground develops and perhaps the regulator does not see the actual battery voltage. I add a ground wire from one of the regulator mounting screws to the battery cable (-).

Got another battery you can try?

 

Garry