3020D starting/oddity

BrotherJoe · Apr 1, 2019

Hi folks,

I've got a 68 3020 diesel that's giving me some odd behavior. All winter (and we had a cold one) it did great firing up--but I could tell it was laboring a bit to start even with the
heater on towards the end. Spring days arrived and the batteries were clearly ailing. Couple weeks ago I went out to start it and it was done--so I put the charger on the batteries
overnight, next morning, no joy. Buddy with the magic wrench came over and after some fussing around testing, we decided it was the starter.

Full rebuild--new brushes, new armature, armature was in bad shape. New batteries. Get it put on, thing fires up like a dream! It's been suffering for a while.

Go finish chores with running tractor.. park in barn, key off, kill motor. Decide to move, engage key, push starter, starter kicks--keeps going with key off! Frantically get 1/2 wrench
disco battery. Start fussing with everything--discover with some sleuthing that the tractor will turn over if I run the light switch. It will stop if I spin the switch around a bit.

My first thought is bad switch. But, how often does that happen? Lots of working around in the dash, those connectors are old and nasty, I discovered I had to zip-tie one of them
together to keep things connected, even after cleaning, after replacing the starter button this winter.

So, I don't think it's a stuck solenoid, but, I'm suspicious of grounding since clearly something is floating high and then engaging the starter.

Thanks,

J

Tx Jim · Apr 1, 2019

Is your tractor's electrical system 24 or 12 volt? Low battery voltage can cause solenoid interior washer to stick to studs.

Bob · Apr 1, 2019

I wonder if you could have corrosion/conductive dirt or damage in one of the multi-pin wiring harness connectors (under the back of the hood or behind the switch panel)?

Or, perhaps some chafed or damaged wires, shorting the solenoid and lighting circuits together?

Also, the coil circuit in the starter solenoid needs to be 100% isolated from the metal case of the solenoid.

ANY internal connection to chassis ground there can cause all sorts of weirdness.

BrotherJoe · Apr 2, 2019

Hey guys; sorry for lag, day job gets in the way of my fun farming..

So; it's a 24V system, batteries should be good--they're new (the winter + the ailing starter finally did them in, so replaced at the same time I had the starter rebuilt). The behavior is
more that actuating the light switch will cause a start--I think even without the safety switches engaged (at least the creeper pedal, it's a PowerShift).

You'll have to be patient--which is the coil lead on the solenoid? I replaced the Pos/Neg plastic cover, and then other than that there are 4 or 6 wires that come out of the safety
systems (tranny, clutch/creeper) that end up on one of the bumps (assuming relays) hanging off the side of the starter.

The thing is dirty and greasy in there, so that seems reasonable, I will try to clean off the connector blocks behind the switch panel--those seem the most suspect, I don't readily see
damaged wiring contacting the tractor frame, but I suppose if it were anywhere, it'd be there. I also haven't checked the starter switch-does polarity matter on it? I guess I wondered
if one pin is isolated from ground/frame and they're reversed, since I replaced it. The rotary switch for lights doesn't look to be in bad shape--but, it is old... Still I'll start with the
harness.

I was hoping this would immediately jump out at something before I started wandering deeply into the wiring harness/switching/contacts!

Thanks for the replies, guys,

J

Bob · Apr 3, 2019

(quoted from post at 10:14:46 04/02/19) Hey guys; sorry for lag, day job gets in the way of my fun farming..

So; it's a 24V system, batteries should be good--they're new (the winter + the ailing starter finally did them in, so replaced at the same time I had the starter rebuilt). The behavior is
more that actuating the light switch will cause a start--I think even without the safety switches engaged (at least the creeper pedal, it's a PowerShift).

You'll have to be patient--which is the coil lead on the solenoid? I replaced the Pos/Neg plastic cover, and then other than that there are 4 or 6 wires that come out of the safety
systems (tranny, clutch/creeper) that end up on one of the bumps (assuming relays) hanging off the side of the starter.

The thing is dirty and greasy in there, so that seems reasonable, I will try to clean off the connector blocks behind the switch panel--those seem the most suspect, I don't readily see
damaged wiring contacting the tractor frame, but I suppose if it were anywhere, it'd be there. I also haven't checked the starter switch-does polarity matter on it? I guess I wondered
if one pin is isolated from ground/frame and they're reversed, since I replaced it. The rotary switch for lights doesn't look to be in bad shape--but, it is old... Still I'll start with the
harness.

I was hoping this would immediately jump out at something before I started wandering deeply into the wiring harness/switching/contacts!

Thanks for the replies, guys,

J

Just a few comments...

"the bumps (assuming relays) hanging off the side of the starter."

Those are two circuit breakers. Both terminals on on should read (+) 12 Volts with respect to the chassis, and both terminals on the other should read (-) 12 Volts with respect to the chassis.

You say you had the starter rebuilt. I wonder is the rebuilder was familiar with the (uncommon) mid-point grounded 24 Volt system your tractor has?

Also, was anything done with the starter solenoid, was it repair or replaced?

You ask which are the coil terminals on the stater solenoid, they are the two SMALL terminal studs.

With all wires disconnected from them, they should NOT show continuity to the metal case of the solenoid. (If the solenoid has been damaged, or replaced with a more common solenoid, there WILL be continuity from those two small studs to the solenoid case.)

3020D starting/oddity

BrotherJoe

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Tx Jim

Well-known Member

Bob

Well-known Member

BrotherJoe

Member

Bob

Well-known Member

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