4020 - major electrical glitch

[KansasGuy]

I have a 67 4020D. I was out mowing weeds when I accidentally ran it out of fuel. After adding fuel and using the manual pump to fill the fuel filters, I attempted to start the tractor but the batteries gave out after just a few seconds. (I have converted to 12V and am running dual 6V batteries) The batteries were 4 years old so I bought new ones, put them on a 2A trickle charge overnight to ensure they were topped up, and installed them in the tractor. All I got when I tried to start it were little buzz/rattle sounds from behind the dash. I called a local dealer and their shop guy said try replacing the starter relay, so I got one and installed it. I took a photo of the old one before I took the wires off and reconnected the wiring to the new one with that as reference. When I hit the starter button afterwards, all I got was one little fzzt and now the two idiot lights on the dash (electric status & oil pressure) are dark. I get nothing when I turn on the key.
I've undone and cleaned up all connection points, battery terminal connections, sanded every spade lug to bright metal, etc.
I've ordered the I&T manual for it just now, and look forward to examining the wiring diagram therein, but would appreciate any advice the community has to offer on my problem, cause my tractor is now sitting 1/4 mile away from the barn out in a field and that just ain't right! Thanks in advance.
Does this thing have a fuse somewhere?
Should I try jumping the starter with a big screwdriver to see if it will crank the engine?

 

[chuck from neb]

Make sure the starter solenoid and
relays are properly grounded to the
Tractor frame I've had that problem
more than once and she will not turn
the starter over if they're not
grounded

 

[matthies]

Just a few things, make sure it is in park, and/or look behind right hand battery to see if the neutral start switch is on the switch(2 yellow wires). The I&T manual won't help much with wiring diagrams. Best
call a friend and pull start it and take it home to fix.

 

[wore out]

''all I got was one little fzzt and now the two idiot lights on the dash (electric status & oil pressure) are dark.''

It's very possible one of the battery cables has an INTERNAL problem and there's a failed connection between the end that connects to the battery post and the wires inside that make up the cable, or at the other, eyelet end.

Shouldn't take all of two minutes with a test light while someone else is depressing the clutch (for safety) and attempting to start the tractor to see where power is lost.

 

[KansasGuy]

(quoted from post at 21:40:20 08/21/22)

''all I got was one little fzzt and now the two idiot lights on the dash (electric status & oil pressure) are dark.''

It's very possible one of the battery cables has an INTERNAL problem and there's a failed connection between the end that connects to the battery post and the wires inside that make up the cable, or at the other, eyelet end.

Shouldn't take all of two minutes with a test light while someone else is depressing the clutch (for safety) and attempting to start the tractor to see where power is lost.

-----------
The left side positive-to-starter cable was pretty corroded at the battery terminal end. I'll get it replaced and see if that does it. Thanks.

 

[miangus]

Probably bad cable connections, the ignition switches do got bad. With no light for the oil light you do not have power at the switch.

 

[susandiane]

All comments are good. I had a ground cable that looked perfect but wasn't. Have also had grounds that looked good and weren't. Good looks apply to horses, women and dogs, not necessairly that order. Never heard of
anyone having any problems having too good a ground or too many of them.

 

[wore out]

Yes, by all means replace the damaged cable.

But I would still suggest grabbing a test light to find out exactly where power is being lost, as I mentioned in my previous post.

In the end, it MAY be a cable (or other connection) that LOOKS good from the outside but has lost continuity internally.

If it DOES turn out the problem is NOT with a battery cable or connection, there's are wiring harness multiple pin connectors under the back of the hood and low down in the steering pedestal that have been known to develop poor connections.

Please post back with the ultimate cause of this!

 

[KansasGuy]

Turns out it had BOTH a bad positive and ground cable. Some gnarly dirty connections behind the dash and a significant but unrelated top end issue also, so I was glad to get it all taken care of in the shop. Thanks everyone! And apologies to whoever I mistakenly "reported".

(quoted from post at 10:37:46 08/22/22)
Yes, by all means replace the damaged cable.

But I would still suggest grabbing a test light to find out exactly where power is being lost, as I mentioned in my previous post.

In the end, it MAY be a cable (or other connection) that LOOKS good from the outside but has lost continuity internally.

If it DOES turn out the problem is NOT with a battery cable or connection, there's are wiring harness multiple pin connectors under the back of the hood and low down in the steering pedestal that have been known to develop poor connections.

Please post back with the ultimate cause of this!

 

[wore out]

Glad to hear you got to the bottom of it!

Thanks for the update!

 

[Tx Jim]

Ditto on thanks for updating your thread. Faulty battery cables & connections are routinely overlooked in a no starting situation.