Question on Replacement Wiring Harness for a 1988 312-8 # 2112K805 29480

[JP56 38]

Have been scouring the site trying to find the cause of my No Start with Ignition Key condition. Ran fine, used it, put it away & a week later ---No Start, but would work if I jumped the 2 main studs on the Solenoid. I figured bad solenoid. Replaced it, same problem! Started looking at ignition switch & wiring. Found a 3" piece of wire with a connector on the end of it laying inside the housing. It went to the red wire that goes up to that annoying circuit board with the idiot lights, but could not tell where the other end snapped off from. Then I noticed the 5 hole connector on the back of the ignition switch had a melted bubble on it, so unplugged it & took switch out. As far as I can tell the switch was the original one, & a couple of the connector tangs were loosened up from age so I decided to put in a new switch while I had everything apart. I noticed that 1 of the 5 wire connections in the 5 lug connector for the switch had 2 wires in it going to one of the tangs on the switch, & I think I found a second one that should have had 2 wires in the connector going to another tang on the switch, so I figured that had to be the one where the broken wire came off of. Anyway, repaired everything, & replaced the burnt 5 prong housing, put it all back together & now still will not start with key, but solenoid can be jumped out & starts up. I have some wiring diagrams from here butt almost none of the wires in my tractor match what colors are spec'd out in the diagrams! My wires are ALL Black, with Tracer lines on them & they all appear to be original wires. They are also very stiff & brittle, so I was looking for a replacement harness for it. I found one, but I have no idea if it will fit my tractor so I am hoping someone here would know, since I cannot find an IPL that gives the actual Harness Part Number for my tractor. 2112K805 29480 Replacement Wiring Harness -  Found this, New Old Stock Wheel Horse Wiring Harness # 108817, but the seller does not know which tractor models it fits. Can anyone here point me in the right direction on this?

[953 nut 55,393]

The part number for the complete wiring harness for your 312-8 is 112217. 

 

Edited November 2 by 953 nut

[Ed Kennell 38,329]

Replace the fuse holder with waterproof in line fuse holders.    This solved the no start problem on my 310-8

[953 nut 55,393]

9 hours ago, JP56 said:

No Start with Ignition Key condition. Ran fine, used it, put it away & a week later ---No Start, but would work if I jumped the 2 main studs on the Solenoid. I figured bad solenoid. Replaced it, same problem! Started looking at ignition switch & wiring. Found a 3" piece of wire with a connector on the end of it laying inside the housing. It went to the red wire that goes up to that annoying circuit board with the idiot lights, but could not tell where the other end snapped off from. Then I noticed the 5 hole connector on the back of the ignition switch had a melted bubble on it, so unplugged it & took switch out. As far as I can tell the switch was the original one, & a couple of the connector tangs were loosened up from age so I decided to put in a new switch while I had everything apart. I noticed that 1 of the 5 wire connections in the 5 lug connector for the switch had 2 wires in it going to one of the tangs on the switch, & I think I found a second one that should have had 2 wires in the connector going to another tang on the switch, so I figured that had to be the one where the broken wire came off of. Anyway, repaired everything, & replaced the burnt 5 prong housing, put it all back together & now still will not start with key, but solenoid can be jumped out & starts up. I have some wiring diagrams from here butt almost none of the wires in my tractor match what colors are spec'd out in the diagrams! My wires are ALL Black, with Tracer lines on them & they all appear to be original wires.

Lets take a look at what needs to happen for your engine to crank over by turning the key.

In the diagram below you will see shat components must work together to accomplish this.

Do a visual inspection of these items to ensure that all wires are tight and connections are clean.

First, check the engine oil level. If the oil is low the low oil switch will energize the "Switching Relay"  preventing the solenoid from receiving its signal to close when the key is turned to start.

Remove the 25 amp fuse and inspect it and the fuse holder, these are quite often corroded and need attention.

When the solenoid was replaced did it have two small terminals on it? If so was one of them connected to ground?

Depress the clutch all the way, doublecheck to be sure the PTO is in the off position, giggle the handle a bit while the key is in start.

With the key off and the spark plug wire removed, take a small jumper wire from the large terminal battery side of your solenoid to the ungrounded small terminal of the solenoid, did the starter turn over?

If the starter turned over from there move back to the switching relay (it is a metal box with wires connected) purple wire and then the light blue wire, did the starter turn over?

The clutch switch is in the tunnel between you feet and a bit hard to reach so we will skip over it for the time being and move on to the PTO switch. Touch the jumper to the purple wire on the PTO switch and then the tan wire while the clutch is down, did the starter turn over?

Let us know what you find.

 

[JP56 38]

Thanks 935 & Ed!

 

I had already decided to replace the 2 fuse holders with the rubber ones with the snap caps on them but just hadn't gotten around to it yet.

 

A note about the fuses, everything I read says the 312-6 should have a 15amp for the lights & a 25 amp for the starting circuit, but mine has a 15 amp and a 30 amp in it.

 

Mine also has NO Seat switch & No Park Brake switch  in it, and I have no idea if the Oil Switch has been disconnected or not, but will check that now that it was pointed out to me as a possible cause of my "No Start From Key" situation. The orange & white wires going to the parking brake switch were cut off 1" from the micro switch, the white one from the test panel to the switch was just cut & left hanging there, & I never noticed if the orange one from the panel to the switch is even still there or not. But since the day I bought it from the seller, that Test Panel only lit up the "TEST" light when you pressed the toggle switch down. Not sure if that little circuit board w the lights & wires connected to it have anything to do with my problem or not, since it always started & ran fine since the day I got it until last week, one week after it was last used.

[953 nut 55,393]

15 amp for the lights/hour meter etc.  and 25 or 30 amp from the battery to ignition switch. Idiot lights have nothing to do with starting wires.

[JP56 38]

50 minutes ago, 953 nut said:

15 amp for the lights/hour meter etc.  and 25 or 30 amp from the battery to ignition switch. Idiot lights have nothing to do with starting wires.

Thanks for the info,

and

Thank You for Your Service!

[gwest_ca-(File Mod) 11,070]