ABout two months ago I bought what was supposed to be a 1991 743 Bobcat. About 3 weeks after getting it home I had been using it quite a bit, and had a problem starting. I thought perhaps the battery was bad, had it checked and it was good. I have since found out that what I bought is a 1988 743B. I am not sure if the alternator is original or simply put on to hold the belt for the water pump. The alternator has no numbers on it, has a motorola module on the back, and one of the wires is not hooked to anything. I can handle electrical work, the schematic i have shows different wiring than what I have on the alternator. I do not know what alternator is supposed to be on the 743, all I know is the one on the unit is not working, I do not know if it is simply a wiring issue, or the incorrect alternator. The wires the schematic calls for are near the alternator, although they are not attached to anything. I need some help if anyone understands what I am talking about. I have a picture of the back of the alternator I can send if anyone would like to see it. I need all the help I can get!
Help Support SkidSteer Forum:
You should only need 2 wires on the alternator, one to the battery and one to the ignition. This is all assuming its not a self exciting alternator that only needs power to the battery.
Can you send a pic of it to me? "taz38sup at yahoo.com.au" the at = @
Don't be put off with the fact its actually a 743B instead of a 743, the B is a better machine, it has larger drive motors and 2 piece axles.
Hopefully its just because the wire is not attached that you are not charging your battery. I have blown my voltage regulator before when i did some welding and forgot to disconnect the battery, you could simply need a new regulator.
If all else fails, you can buy 1 wire alternators that basically bolt rite up, they are pretty cheap too, Ken uses them and is very happy with their performance.
Can you send a pic of it to me? "taz38sup at yahoo.com.au" the at = @
Don't be put off with the fact its actually a 743B instead of a 743, the B is a better machine, it has larger drive motors and 2 piece axles.
Hopefully its just because the wire is not attached that you are not charging your battery. I have blown my voltage regulator before when i did some welding and forgot to disconnect the battery, you could simply need a new regulator.
If all else fails, you can buy 1 wire alternators that basically bolt rite up, they are pretty cheap too, Ken uses them and is very happy with their performance.
skidsteer.ca
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If it is a the alternator just switch the Korean "Mondo" for a 60 amp Delco, self exciting
They are common as nails at any auto parts place or starter rebuild shop. About $60 US locally. I learned when I took mine into my local rebuild shop, the owner just laughed while he pitched mine in the trash (we know each other farely well) and said
"Son, we don't fix those, we can sell you a Delco for 1/2 the price of the parts"
and the best part is it bolts right up, no mods needed.
Ken
I e-mailed him back a few details, hopefully it is of some use....
It doesn't look like a factory alternator, but i gave a few tips on testing it, hopefully something will come of it. Was a little rushed as i was at work when i typed the e-mail
If I walk up to the bobcat and look at the center of the Hub, it is welded, no bolt. I called bobcat, gave them the serial# and they told me it was a 743B, from what you say, and what I have been reading, it sounds like it is not a 743 B. As far as the alternator, I have tried checking things with a voltmeter, and there is no charge whatsoever while the engine is running. I think I will go with the delco, if someone can tell me exactly what I need to get, it seems like an easier solution.
skidsteer.ca
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I believe they call them a delco 21si, they were the most common ones used on late 70's early 80's v8 engine (and many others, but my 82 chev pickup 305 used one.) vehicles without to may power options. They look just like this
http://www.newindo.com/delcoremy/pdf/19010154.pdf
but there are many amperage levels that appear close to the same. I would not recommend going much over 60 amp. Also be sure to get one that is "one wire" or self exciting, it is a cheap retrofit to upgrade a 3 wire delco to a 1 wire.
Ken
Ordered an alternator today, 63 amp self exciting $63.00 with the old alternator. I figured that would be the easiest fix. Thank you for all of your help. I will let you know how things work out.
Installed the new alternator, and a volt meter this evening. The new alternator is working very well. I could see the differences in the two alternators, the old one definately was put on merely to hold the belt on. Even with the few repairs I have had to do, I figure $5400.00 for a 1988 743 with a new engine will serve me well in my quest against the pine trees on my property. Thank all of you for your help.
