electrical problems

[don_and_ally]

I have an elderly friend who owns a 1953 cub. He recently sold it to a young man who converted it to a 12 volt system. The guy didn't pay him so he got it back. The conversion was shotty at best. When he went to start it, it smoked every wire on the thing. He has asked me to take a look at it and see what I could do. I re-wired everything in a way that makes sense to me and fits most of the information I have found. It looks like he used a GM alternator. The problem I am having with it now is that it blows a 30 amp fuse when you cut the ignition switch on right away. The starting circut works fine. The lights work good when you bypass the ignition. I have narrowed the open as being across the ignition coil. That is the only one I can find, but unless I am mistaken that is supposed to be there. If anyone can offer some help on this I would be very greatful. Thanks in advance.

[Bigdog]

I'd vote for some fried diodes in the alternator.

[Daniel H.]

Here is the best 12V conversion I have found. It says Super M, but it is the same for all Delco conversions.

http://albums.photo.epson.com/j/ViewPhoto?u=4001561&a=30065733&p=60243702

Note: You must have the warning lamp OR a diode in the circuit or the tractor will continue to run even when you turn off the ignition switch.

[don_and_ally]

Thanks guys,

The diagram was great for my ego because I had the wiring right. I have the diode in there as it shows. But the kick in the seat is the resistor. I should have known better and checked that. The coil is not an internal resistor coil. I'll pick one up and let you know how it goes. I am hoping the vote for the diodes in the alternator gets vetoed. The coil is a cheaper fix. Thanks again.

[Dale51]

Here is the best 12V conversion I have found. It says Super M, but it is the same for all Delco conversions.

http://albums.photo.epson.com/j/ViewPhoto?u=4001561&a=30065733&p=60243702

Note: You must have the warning lamp OR a diode in the circuit or the tractor will continue to run even when you turn off the ignition switch.

I bet his alt's. don't last very long or the diag. is wrong.
You can not feed #2 12volts continious or the voltage reg. will burn up.
This I know from doing it.

[don_and_ally]

Well I got the new coil, and a condenser. Hooked it all back up and got no flow thru the amp meter. So I bypassed it and poped the fuse again. The wiring was exactly as the diagram shows. With the minor exeption of 10 ga. wire all the way around, and 14 ga. on the lights. That is just what he had on hand. My current plan is to pull the alternator off tommorrow and take it to get tested to see if Big Dog was on to something. After reading Dale's comment I have to asked what solution you have found. If I am reading you right you are saying that running the #2 post to the Bat post is not the best hook up. Is the amp meter necessary? I would think not. I hate to just keep throwing parts at it. I'll keep you posted.

[Dale51]

Well I got the new coil, and a condenser. Hooked it all back up and got no flow thru the amp meter. So I bypassed it and poped the fuse again. The wiring was exactly as the diagram shows. With the minor exeption of 10 ga. wire all the way around, and 14 ga. on the lights. That is just what he had on hand. My current plan is to pull the alternator off tommorrow and take it to get tested to see if Big Dog was on to something. After reading Dale's comment I have to asked what solution you have found. If I am reading you right you are saying that running the #2 post to the Bat post is not the best hook up. Is the amp meter necessary? I would think not. I hate to just keep throwing parts at it. I'll keep you posted.

Boy is my face red The diag. is right I was thinking that #1 and # 2
Were the other way around I went & looked at my diag this morn.
I guess when you are tired you should look before you type. SORRY!!!!!!!

But here is a question what fuse do you keep blowing?????
There is only One that I know of that is lights only.
Also did you switch the batt. from pos. ground to neg. ground?
Also take a look at this wiring & see if the rest of the wires are right.
http://www.antique-tractor.com/CubFAQ/cubwiringlate.jpg

As for testing the alt. I would just unhook it & see if it still blows the fuse (cheaper than having it checked).
Keep us posted.

[don_and_ally]

Thanks again Dale I sure do appriciate it. I pulled the Alt today and the ammeter. I'll take them to the parts store in the morning. They test for free there. Got a new head ache when I pulled the alt though. The bracket for the tension adjustment was "welded" to the water neck. I can't tell for sure but I think it was JB weld. Either way it was poor work and gave loose. I guess I will have to do it right now too. The fuse is a 30 amp in line that I put in the line from the starter post to the ammeter. Just to protect the wiring. Thanks again.

[don_and_ally]

Ok, the alt did test bad, thanks Big Dog. The coil now reads 3.7 ohms across like it should. Everything is hooked up exactly like the diagram and still blowing the fuse. The only thing that has not been replaced is the switch which seems to be working fine when checked with an ohm meter. The only other thing I have not cracked into is the distributer. Would the points be able to cause such a problem? I would not think so because it should be able to sit with them closed, be cut on and started. The fuse blows instantly so I am at a loss. But what ever caused the problem from the start cooked everything before and I am afraid to wire it with out a fuse. Open to your thoughts guys. Thanks.

Oh yeah the fuse is a 30 amp in line between the starter and the ammeter.

[Dale51]

Just A thought! I wonder if when you turn the switch on if shorts to ground even though it test open or closed with the meter.
If that is not it then I would unhook all wires Turn the swich on & reconnect them One at A time till you find which blows the fuse.

[Bigdog]

Clarify something for me. You said the fuse is in the line between the starter and the ammeter and it does not blow until you turn the ignition switch on. Is that correct?

[don_and_ally]

You are correct Big Dog. Dale I have considered what you suggested and that may be right. I might just grab a new switch and see. I tried pulling all the wires about a hundred times and it all seemed to lead to the coil before. Have not tried since I replaced the coil. Time just never seems to be enough. Thanks again.

[don_and_ally]

OK Cub fans, are you ready for this. I am not sure wether the alternator cooked the battery or the battery cooked the alternator first. I did notice that when I took out all the burnt wire that there was nothing hooked to the #1 post on the alternator. But either way I got a hunch to check out the battery today. It would read 12.1 volts for a couple seconds, then it would read -12.1 for a while. So with that I took it to get it tested and sure enough it was shorted between 3 cells. Went out and hooked up a new battery and she fired off and purred like a kitten. Problem solved. Hope this little brian buster I had, and the lessons learned from it can bennifit you all. You will be happy to know that she mowed about 3 acres today and I swear she smiled when I put her up. Thanks again for all your help.