Jim Good deal, sounds like you are close to success. You're a good writer and I always enjoy what you have to report, however, I still envy your justification to own a Unimog.
Harry Watkins Newton, MS 86 SDL Silver 85 300D Euro 86 SDL Gold 81 240D manual trans ----- Original Message ----- From: "Jim Cathey" <[EMAIL PROTECTED]> > Thought I'd keep y'all up to date since there has been some interest > in this in the past: > > December 5, 2005 > > Remounted the positive battery cable to eliminate the short to ground, > then hooked up the battery bank and tried flipping the start switch. > Nothing. I jumpered the start terminal on the solenoid and it clanked > nicely, but there was no sign of engine turnover. I didn't have any > more time to mess with it today as I spent most of the day working on > the snowblower. (Again.) I don't even know if it was drawing any > starting current, nor whether the feeble battery bank was capable > of driving anything more than the solenoid. > > December 12, 2005 > > With holiday parties temporarily put to bed I was able to look at the > genset again. Armed with a couple sheets of enlarged schematics, two > as-charged-as-they'll-ever-be crap batteries and the Fluke I went out > into the cold. With the battery bank hooked up, I was able to find > that +24V was not making it to the Start/Stop switch, yet did make it > to the emergency stop switch. According to the schematic the most > likely offending party was the overspeed switch, or if not installed, > Jumper #1. I looked at the terminal block where the switch would have > been hooked up, and found a jumper. OK; what I did _not_ find > were _two_ screws hooking the jumper to the block: I only found > one. So I raided the junkbox to find a suitable screw and hooked it > back up properly. With that done, the Start switch now had power to > it, so I flipped it on. CHUNK! The starter relay fired. A second or > so later, it was CHUNKA-CHUNKA-CHUNKA... The feeble battery bank was > dying, causing rapid cycling of the solenoid. One of the two 12V > batteries reads 0V during this condition. The motor never did turn > over, but according to the Fluke I only was getting 100A or so at the > peak of current draw. Hardly enough, I'd think. I'm going to need > some real battery power to proceed much further. I put the feebs > back on the charger anyway. > > December 13, 2005 > > I cleaned up and resoldered the ruined positive battery clamp back to > its cable. (Acetylene sure makes this kind of heavy heating a snap.) > I hope this will end up being part of the inter-battery tie cable. > Interestingly enough, the clamp is brass, not the more common lead. > > I pulled the spark plugs and tried 'starting' it again. No joy, so I > put a wrench on the tail of the exciter and twisted at the same time. > It didn't take much of a twist and the set started turning, about a > half second before the batteries died again. I really need new > batteries! > > ...I went out and bought two used batteries at the U-Pull. $26, I > hope that this will cure the problems for now. When I got home, I put > them on the charger for tomorrow. I bought the two biggest batteries > they had. Not matched in size, c'est la vie. > > December 14, 2005 > > I hooked up the 'new' batteries, and hit the start button. > WOOKA-WOOKA-WOOKA-WOOKA... Hooray! The thing spun over easily, at a > pretty good clip. I put the spark (paint!) plugs back in, and tried > again. WOOKA-WOOKA-WOOKA-WOOKA... Cool, this thing is going to work! > It draws more than 350A initial starting current, this drops off > pretty good once it's spinning. I notice no sparking or any other > evilness on the exciter/starter, so that's OK. The shop rag over the > exhaust port bellies up nicely when it's spinning. > > -- Jim
