TO-20 electrical short?

[buckeyepost]

My latest problem with my Ferguson seems to be electrical. Put a new set of point in it and she ran fine for about 20-30 minutes and then started losing power with the mower engaged. I've been told that there might be an electrical short somewhere. The tractor has been converted to 12V but was probably done in an afternoon with a case of beer... not the greatest job, so I planned to rewire the entire thing. So, I guess my question is, where would the short likely be? On the ground block? Ignition switch? I'm not too familar with electrical systems but if I could find a good diagram somewhere it shouldn't be too hard, right? You guys have saved me before, hope someone has experienced this before and knows where to look.

 

[tommu56]

Check the cap in th3 distributor make sure its for 12volt,
Maybe the points are "burning up" if the cap is bad it will do that and loose power because the dwell goes off.

tom

 

[Jerry/MT]

My latest problem with my Ferguson seems to be electrical. Put a new set of point in it and she ran fine for about 20-30 minutes and then started losing power with the mower engaged. I've been told that there might be an electrical short somewhere. The tractor has been converted to 12V but was probably done in an afternoon with a case of beer... not the greatest job, so I planned to rewire the entire thing. So, I guess my question is, where would the short likely be? On the ground block? Ignition switch? I'm not too familar with electrical systems but if I could find a good diagram somewhere it shouldn't be too hard, right? You guys have saved me before, hope someone has experienced this before and knows where to look.

Start the tractor and work it. When it stops, immedialtely pull the center wire out of the distributor cap, hold it near (1/4") good ground and try a start. You should have a FAT, BLUISH-WHITE SPARK, the color of lightning. If you don't then you'll need to check further. If you do, the ignition isn't the poblem it's most like fuel delivery being limited.

Since you have a 12V conversion, make sure that you have a real 12V coil (like NAPA IC-14SB) or you have a 6V coil with a resistor in series with it in the primary ignition circuit.The primary circuit is limited to about 4 amps max and if someone put a 6V coil in with out a resistor to limit the current to 4 amps max, the insulation melts in the coil in about 30-45 minutes and you loose spark. The other possibility is a bad key switch. They get gunked up and have a high resistance that increases with time and can cause the ignition to fail in about 15 minutes. In both of these scenarios, once the offending component cools down it will run again only to cause another shut down. The solution is to replace the coil with a correct one (NAPA IC-14SB or if it's the key switch, replace that).

Wiring diagrams can be found on url=http://www.fergusonenthusiasts.com. You also might want to get a Ferguson Shop Manual. If you wnat to get more advice on the Fergusons, try the Harry Ferguson Forum on Yesterdays Tractors website.

Hope this helps you.

 

[buckeyepost]

Thanks guys! They key switch might be my problem. I will check the coil type but I just replace it at CarQuest when this first started happening over the summer. AAAAND, I mowed with it running fine the first half of this season, probably had 15-20 hours on it and then one day it just stated acting up like this. Here is a list of what I've done since it started lopping like this and losing power:

- rebuilt carb
- drained fuel tank and blew out gas lines
- disassembled and cleaned fuel bowl
- replaced coil, plugs and points (twice)
- adjusted timing
- new battery

Here is a crappy picture of the coil/dist side of the tractor if it helps.

 

[buckeyepost]

Close up...

 

[Jerry/MT]

Close up...

A quick way to check the ignition switch is to put a jumper across it and start the tractor and work it. If it doesn't quit, you've found the problem. ust remember to disconnect the jumper when you need to shutdown because the key won't shut it down when it's jumpered.

 

[Jerry/MT]

Close up...

A quick way to check the ignition switch is to put a jumper across it and start the tractor and work it. If it doesn't quit, you've found the problem. Just remember to disconnect the jumper when you need to shutdown because the key won't shut it down when it's jumpered.

 

[buckeyepost]

A quick way to check the ignition switch is to put a jumper across it and start the tractor and work it. If it doesn't quit, you've found the problem. Just remember to disconnect the jumper when you need to shutdown because the key won't shut it down when it's jumpered.

Are you talking about doing this on the key switch? How would I go about doing that? Just take all the wires off of the key switch and then give it constant power or something and see if it runs?

 

[tommu56]

buckeyepost

If it is a short it would normally be blowing a fuse.

It sounds like something is "opening up" in the curcuit not "shorting"

I'm assuming your tractor negative ground?

most of the Ferguson prints look positive ground

Please read all the instructions first before attempting!

The simplest test disconnect battery lead at the coil that comes from the harness tape it up.

Then run a wire from the coil bat terminal to 12v+ battery post (assuming it neg ground) 12- battery post for positive ground.

Turn key to activate starter this will bypass the key switch run circuit and any thing in the harness.

You will have to remove this wire to stop engine so be careful.

If it doesn't turn over take temporary wire off and get back to us and we will trouble shoot the cranking problem.


tom

 

[tommu56]

buckeyepost

here is a link to a ford wiring diagram yours should be similar.

http://www.ntractorclub.com/howtos/pdfs/Wiring_Diagrams_for_Ford_Tractors2.pdf