Hey Guys This is a 944a Serial # 43a4392 that has a charging system problem. I just had this post and pictures almost finished and lost it in the either. ... ( hence the shorter posts )
As seen in the picture I found a couple shorts in the resistor on the back of the regulator. I had put a couple newer fresh batteries in the machine and had run and driven it a bit before I changed the regulator. I put a fifteen minute surface change on each battery ( I know I should have fully charged them ) I polarized the generator successfully (I believe) at the regulator ( got the little spark )
I started the machine and heard all the regulator solenoid buzzing very rapidly. (?) Then I smelled something burning that smelled electrical so I shut it down and cut the power. I'm now wondering if everything was ok At that point because now I seem to remember the resistors on the back of the new regulator were coated with some sort of resend or paint? (And that's what I smelled? ) could this have been the cause of the smell? I plan on looking at the back of the new regulator. If it seems okay what would be my next test? Pull the belt on the generator and put power to the armature terminal and see if the generator spins? I'd sure appreciate your help, thanks Steve
Did you make sure the ground strap was hooked on one of the mounting screws? Those rubber mounts don't conduct well. As I recall the relay shouldn't buzz... Yup, the old motor test, dang I wonder how many years it's been since I worked on a machine with a generator? LOL
Thanks Trax yes I put a new one on but now that yo mention it I'll have to test it. It's kinda difficult to access under the seat. this machine is in no hurry to go anywhere I don't remember ever hearing a regular buzz so much. I didn't find any hot or burned wires but the smell thru me. seem to remember a coating on the resistors. I don't know how soon I'll be go back out there as I'm working on something elsewhere I'll let you know what I find. Thanks again Steve.
It's been many years since I've done anything with a generator other than rip it off and scrap it. You can buy a 45 amp one-wire Delco 10Si at NAPA for $45
Thanks Mitch, yes I considered that too. But I didn't know they were that cheap! I don't know if the owner wants to do that it's just one of a few side projects when I'm not fixing The newer equipment. But I've run across similar people asking for such . It could be used on site to remove a part an his 966 I guess I could just it for that. And it has a Cat rebuild with less than a hundred hours. Owners 86 and wouldn't mind selling it. How are you doing hope all's well best wishes Steve
That's a new regulator, right? I'm not familiar with that particular one, but looking at the size of it it has to be a "two bobbin" type and therefore pretty simple. As you only have three terminals, it will definitely need the case grounding so as lantraxco suggested make sure this is in good order first. If it still doesn't work, and assuming you've got it wired up right and checked the wires for continuity, you should check the generator is working as that is the only other component in the system. Here's how, and this applies to all dynamo systems (AFAIK) Disconnect both wires from the generator. Set your multimeter on Vdc. Connect the +ve lead to the big terminal and the -ve lead to the generator case. Start the engine. You should see about 1 to 2V, rising to perhaps 4V as the engine speed increases. Drop the engine down to low idle again. Connect the two terminals on the generator together with a jumper wire. The voltage should immediately go up some. SLOWLY raise the engine speed while watching the meter carefully. You should be able to reach 14V for a 12V system or 28V for a 24V system. You shouldn't have to rev the engine much. If you go too fast you can generate a big voltage and damage the generator. If all the above checks out, you should have a working charging system. Good luck.
That's a 24 volt machine innit? Or am I mistaken?
And that would be a 24V alt?
Oops. Okay, a little more money, but probably still cheaper than a new regulator and the time to chase bad wires and etc.
Thanks Mark for the info grandpa it's 12 volt. Yes it's an old generator not an alternator. The owner is 86 and owns a 966 says he doesn't know how much longer he's going to shift dirt. I wanted to play with it for spite also can't put the bonnet and exhaust on it with out it charging ? I think this would make a great farm machine for someone since the engine only been run a little since Cat rebuild. There's an excavator and dozer on site that may go for scrap soon. These three machines are the least of his troubles. I hope to get the chance to find this loader a loving home. I like to play with electricity but have my limits :^ ) I hope to get the opportunity to repair the charger put the bonnet and exhaust on it and let the new family tend to the rest. Thanks again guys for your help and interist. Steve