Start Shorting

Post support questions about your JD350 and newer crawler here
Post Reply
Mrfriend
MC crawler
MC crawler
Posts: 6
Joined: Tue Nov 27, 2018 5:09 pm

Start Shorting

Post by Mrfriend » Mon Dec 10, 2018 8:31 am

Need to tap the big brains - my JD350B is shorting out at the battery Positive terminals and getting hot and smoking. Note - I have had trouble getting it to shut down when turning the key off now and then and with it just cutting out. That is what happened, it cut out, it was trying to start fine but positive cable was getting hot at the positive terminal and at the starter, then it would not turn over at all. The batteries are testing at 12.75 volts each and are new (less than a month). The Positive battery cable was a bit worn near the batteries where it goes through the side of the box so I replaced it with a 00 welding cable, replaced the negative cable as one was looking rough. Still nothing, it would not turn over at all. I tested at the starter and was not getting voltage to the solenoid when pushing the starter button. I opened up the dash and tested the push starter button, it is fine. When doing so I found most of the wire eaten up by mice. Of course I cleaned out the mice droppings, oh boy! Also found some chewed up wiring under the floor plate so I taped it all up good as well. I replaced the push starter button wiring and taped up all the other wiring that had insulation chewed up. Still nothing. I started wiggling the key in the key switch and I got it to turn over a little. I have not tested the voltage coming from the key switch to the push starter switch yet. I am thinking it might be the key switch itself at this point given what is happening. Any other thoughts or experience? I went ahead and replaced the fuel filters and air filter while it is down. Have a small hydraulics leak back at the root rake I am going to fix as well and going to just give it a good one over - fill hydraulics, etc. This one is new to me and has been running great except until recently with the cutting out now and then, not shutting down when ignition turned off and throttled down, and now the short issue. I don't think the guy I bought it from did much on it. Steve, Brunswick GA

User avatar
Lu47Dan
1010 crawler
1010 crawler
Posts: 401
Joined: Mon Feb 11, 2008 3:17 pm
Location: NWPa

Re: Start Shorting

Post by Lu47Dan » Mon Dec 10, 2018 4:40 pm

Hate to say it, but it would be wise to trace all the wiring to find any other mouse eaten or bad spots in it. Had a local farmers 200hp Case/IH tractor burn to the ground a couple of years ago because of a dead short on the cable running from the batteries to the starter.
Also you might want to disconnect the batteries when you are not using it.
Sounds as if the key switch is bad. Disconnect the wire from the key to the push button use a jumper wire to supply power (from a known good power point) to the push button switch, try the pushbutton and see if the starter engages. Key switch dies not need to be on, all you are doing is seeing if the pushbutton switch is working correctly.
Dan.
1956 420C with GSC blade
Tools are to men as shoes are to women , you can never have too many !!
Used diesel engines are an adventure any way you look at them !!

Jim B
350 crawler
350 crawler
Posts: 2072
Joined: Sun Nov 05, 2017 11:36 am
Location: western Maine

Re: Start Shorting

Post by Jim B » Mon Dec 10, 2018 4:51 pm

Good evening,

Just to clarify; you have replaced the battery cables. Has the problem with them heating and smoking at the ends been cured? If not cured, do you have two batteries and are they hooked in parallel, negative ground? Are the battery hold downs clear of the terminals?

Mice can certainly wreck things. After making sure you have power to the starter button from the ignition switch. If you unhook the start wire from the solenoid and hook a jumper wire, with a fuse in it, from the battery terminal on the starter to the wire, you can back feed to the starter button and see if the circuit is complete back to the starter button by checking the wire with a test light, or voltmeter, at the starter button end. That can be easier than trying to hold the button in the start position and checking. Also unless it has been bypassed you should have a neutral safety switch between the button and starter solenoid. If it has failed or is not adjusted right it can cause a no start condition. You can do the same with the fuel solenoid wire. Unhook it and back feed it, check at the ignition switch end. Wiggle and tug on the wiring as you check to see if there is a broken, loose, or worn spot in a wire you missed. Check any plug in connections carefully. Some of the symptoms you describe do point towards the switch. Once you are sure the wires are good check the switch functions with a test light, or voltmeter.

User avatar
gregjo1948
350 crawler
350 crawler
Posts: 1000
Joined: Mon Aug 30, 2010 5:58 am
Location: Newark Valley,NY,USA

Re: Start Shorting

Post by gregjo1948 » Tue Dec 11, 2018 5:51 am

Off subject a little but, I just picked up a Ford 2000 that had set too long. The clutch was inoperable so, I had to split the tractor. I found the bell housing full of mouse nest, turds, piss, and even a couple residents. Center of the clutch disc rotted from friction area and the real shocker was, there were several teeth destroyed on the starter ring by these furry little critters. Merry Christmas!!!!
JD 350B diesel 6way blade, Case 580B Loader/backhoe, Farmall 504 high crop w/ flail boom mower, International 404 , International 284 diesel w/belly mower, 1972 Ford F600 dump truck, Galion 3-5 roller, Allis Chalmers D17, 1620 Ford

Mrfriend
MC crawler
MC crawler
Posts: 6
Joined: Tue Nov 27, 2018 5:09 pm

Re: Start Shorting

Post by Mrfriend » Sun Dec 16, 2018 5:45 pm

Well, I played a bit this weekend. Wired up a new key start switch. Got a bit of crank on the starter now and then mixed with a whine noise. Cross connected the battery cable to the soleniod with the S terminal on the solenoid and got the same result so all is good at the key switch and push start button. So I am no longer getting smoke from the battery terminal but, I am getting smoke from the starter itself. It is coming from inside the starter threw the hole where the thin metal piece goes in and on the other end is connected to the solenold battery connection. Actually from inside the starter. Never seen this before. When it does try to crank, it is very weak but the batteries are new and charged (12.53v). The batteries are not in parallel making 24v, just each grounded and the two positives connected together. It was a little hard to test the volts at the S terminal when pressing the start button. Jumps around but did see upper 11volts so I am going to disconnect the wire at the S terminal and then cross connect the wires at the push button switch to get a steady read of voltage down to the S terminal. Thay will at least confirm I am getting 12volts down to the soleniod; however, given the smoke coming out of the starter itself, I am thinking something fried inside the starter. I will check additional wiring. What you all think, the starter? Ever seen one have smoke coming out of the starter where the 12v from soleniod/battery goes in? I will take a pic.

Jim B
350 crawler
350 crawler
Posts: 2072
Joined: Sun Nov 05, 2017 11:36 am
Location: western Maine

Re: Start Shorting

Post by Jim B » Sun Dec 16, 2018 6:09 pm

As you describe how your batteries are hooked up, they are in parallel. Positives together and negatives together are parallel and make 12 volts. If one positive went to the starter and its negative terminal was connected to the second battery's positive terminal with the second battery's negative terminal connected to ground they would be in series and make 24 volts.

You should not have smoke coming out of the starter. I have seen it before and it doesn't mean anything good. It may not be fatal, but I would take it off and either get it repaired, if you have a good electrical shop you use, or replace it.

Mrfriend
MC crawler
MC crawler
Posts: 6
Joined: Tue Nov 27, 2018 5:09 pm

Re: Start Shorting

Post by Mrfriend » Tue Dec 18, 2018 8:05 am

Ahhhh, duh, that is right, series vs. parallel My poor old brain cells can't remember s@%t now days. Yeah, I am thinking the short probably fried something in the starter itself Everything else seems to be okay now but I am going to check out more of the wiring and clean up the main wiring connector as well. I don't think the guy I bought it from ever really did much of anything. I believe the actual short was from the key switch BAT terminal wiring bare spot hitting against the dash steel. It has worked good except for recently with the electrical. Now, to get that starter off, what joy awaits me. :shock: Thanks everyone for the input, thoughts, guidance, etc. Just not something I do very often now days. Steve in Brunswick, GA

Post Reply

Who is online

Users browsing this forum: No registered users and 22 guests