7272 electrical

barticus73 · Aug 1, 2006

Does anyone have a wiring diagram for this series tractor, or even one similar. Last year I had the starting troubles and installed the relay that was discussed and that worked like a charm. All of the sudden now I turned my tractor off this weekend and it wouldn't start. I jumped it with my truck and it fired right up. The battery was dead. Took it to Sears (Diehard) and they tested and said it was bad and gave me a new one free. I put the battery in this morning and it didn't do anything. I hooked a voltmeter across the battery plus and minus terminals with the key off and read 12.35vdc. With key one click to the right the voltage dropped to between 7 and 8vdc(fuel pump?) is this good? Then one more click to start position and nothing. I know I need to check the relay but are there any other things that could go bad? Is there a way to check the battery cables? I think I am going to try and jump the battery positive right to the solenoid on the starter bypassing the relay and see if it trys to turn over. I really would like to find a wiring diagram for this tractor though.

Thanks,

Jerry

MajMac392 · Aug 1, 2006

Barticus, I've got the manuals for my 7234 and I think it has both 719X and the 727X series in it. I assume it has diagrams for all three series but I'm not sure. If I get home at a reasonable hour tonight I'll try and look it up. You asked about the battery cables. I think the negative to the battery bolts onto the frame so that should be easy enough to look at for corrosion and tightness. The positive doesn't have a very far run to the starter so I would thing you could check that easy enough as well, for tightness, and corrosion. You could check the cables for continuity with an ohm meter but unless you discover a lot of corrosion on the cable or clamps I wouldn't think it would show much.

barticus73 · Aug 2, 2006

Well, the problem ended up being a bad positve battery cable. I checked everything it seems and as soon as I swapped this cable it fired right up. Checked the battery voltage running and it looks like the alternator is charging the battery so this cable must have been the problem. I would still like to find a good wiring diagram for this tractor.

MajMac392 · Aug 2, 2006

barticus73, Glad you got it going. Here is a .pdf copy of the wiring diagram, I hope it attaches ok. There is only one page in the manual and it covers both the 723X and 727X series.

barticus73 · Aug 2, 2006

Awsome, I have wanted that wiring diagram for years. What manual did you get it from?

Bob_Bainbridge · Aug 2, 2006

I don't know if MTD did this across the board but on my 3235 there was no ammeter or voltmeter like my 1450 had. I noticed the voltage regulator failed on my 1450, long before the battery went dead, because of the ammeter. I purchased a cheap 30 amp meter at TSC and found a flat area, below the indicator lights, large enough to cut a mounting hole with a hole saw. I wired it in series to the red wire coming off the starter terminal (not the large battery cable). It goes up to 10 amps immediately after starting the tractor and then quickly moves back toward zero.

Bob B.

MajMac392 · Aug 2, 2006

barticus, the diagram came out of the Cub Service Manual I bought from the dealer when I bought the tractor. It is on about 11" X 17" paper in the book.