Re: Farmall 656 motor issues

Posted by karl f on March 12, 2011 at 19:39:10 from (172.162.104.50):

In Reply to: Farmall 656 motor issues posted by sflem849 on March 03, 2011 at 18:36:34:

Keep diagnosing. you can run a jumper wire from the battery to the coil or the R terminal on the solenoid to see if that makes spark at the coil. Are you using a spark tester or plug on block or just assuming a no start is no spark? Also check voltage at the R terminal of the solenoid, as it is fed with a resistance wire with the ignition switch on If it isn't 8-12 volts there, you have rewiring to do. The R terminal should goto 12 volts when the starter is engaged. any add on stuff like a Murphy Switch or electrical implement controls or cab stuff can cause all kinds of problems whether they're wired properly or not when there is some aging.

I rewired our 656 Farmall gas from scratch about 8 years ago. Even though I basically followed the factory wiring, I did cut some corners in supplies that I now regret but it does work flawlessly (I learned some new things afterwards). The original wires were rotten. Mine has an alternator from the factory, and I reused the original externally regulated type.

What electrical system do you have?

The final straw was when i had the cowls off for a TA adjustment and I saw a corroded bare wire showing through rotted insulation which then broke while attempting to tape it--tractor wouldn't fire after that. There are some redundant, overly complicated, and overloaded wires in the harness. But it's not really a bad design--If you get an original type harness, I would recommend eliminating the lights from it and modifying accordingly, even to the extent of relays for a work tractor. Also if you have a generator and are thinking about an alternator, a harness for a 666-686 gas might make it easy as they used a 3 wire 10si Delco that is internally regulated. Those models are 99% mechanically a 656 plus different stickers. There are a few vendors out there that specialize in the IH harnesses and most know what works when you are attempting to interchange. If you want to wire from scratch I'll help you: whether you want to copy stock or simplify/improve the wiring. If you simplify, it's basically Bob M's H/M diagrams plus a few more wires for the dash and fuel solenoid. The improvements would be proper gauge wire for critical circuits, 12 or 10 gauge wire from bat post of starter feeding a terminal for the lightswitch, lighter, etc.; then minimally 1 relay for the field lamps (rear worklamp and front floodlamps), and redundant ground wires from fender to chassis. Do not eliminate the clutch switch for starting. I did not use a resitance wire (hard to find anyway) from switch to solenoid R terminal, rather I used a normal wire and a 12 volt coil. The R terminal still helps at starting imho. Couple years down the road I ended up installing a pertronix so the resistance wire would have had to be removed for proper operation.

So if you would like detailed help, send me an email (shows in modern view) as I'll have to dig out my notes and put it together in writing. For now, diagnose :)

karl f

Replies:

Add a Reply Name: E-Mail: Subject: Comments: Optional Link URL: Link Title: Optional Image URL: Optional Video Title: Optional Video URL: Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.   Advanced Posting Tools   Upload Photo  Select Gallery Photo  Attach Serial # List  Return to Post

TRACTOR PARTS	TRACTOR MANUALS

We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]