I have a JCB midi cx tractor loader backhoe I bought new that has been a super solid machine for about 10 years. Lately it has developed an electrical problem that I think may be related to the alternator. It had been acting like the battery was not very hot (not much cranking power) even after using it for hours for a while and then on Wednesday it started blowing the 40A ignition fuse immediately when I tried to crank it. After going thru several fuses, I started to track down potential electrical problems. One of the terminals on the starter was totally rusted up and corroded, and when I went to unhook it to clean, it broke off - so I took out the battery (had it tested and was fine both on voltage and cranking amps - which wasn't surprising because it wasn't very old) - and replaced the starter - but same problem immediately blowing fuses. Eventually, I realized if I left the wire going from the alternator to the starter off - it would crank over like new, start, and run fine. Unfortunately, it of course wouldn't charge the battery in that condition. Equally unfortunately, I had a lot of work to do, so thinking that it wouldn't do any damage other than running the battery down, I just left the alternator disconnected and went about my work. Eventually after about a day of work and changing many different hydraulic implements which required an engine stop/start the battery ran down. I jumped it and let it charge and it started fine, but at this point, the hydraulics were dead (not to the axles just everything else).
I've heard that if the diode/rectifier in the alternator goes bad it can put a substantial draw on the battery - I'm wondering if this is why the fuse was blowing and why when it was hooked up the tractor acted like it didn't have much cranking power for the last month. I took the alt off and took it to two different auto parts stores and they could find it in their system but both said they didn't know how to test it because it wasn't a standard car/truck alt. Is there a way to easily verify the diode is bad - it has three terminals - the big one that goes to the starter is labeled B+, one labeled D+ I assume might be the diode, and one labeled W I'm not sure on? I think this is the alt (for a heckuva lot less $ than either of the parts houses wanted) - the JCB has a 50HP Perkins in it that is the same as cat and others use in a lot of their smaller skid steers, etc.
Amazon.com: DB Electrical ALU 31 Perkins Engine Alternator For Lucas 24479,24481,24344,24479,2448 ,24481,Jcb 7144 152, 714322 , 714/322 , 714/4 152,714/4 153,Caterpillar 225-3141,225-3143, 3 5-3661: Automotive
Are there not shops around that rebuild fix alts anymore - I asked both Napa and Oreilly and they acted like they had never heard of such but I'm pretty sure that's what we did when I was a kid and dad's tractors had alternator problems.
Does my theory above about the alt match the symptoms/seem likely?
On the hydraulics - I checked all the fuses and they looked ok - but I'm wondering if maybe some wild ac before I disconnected it or using it with lower voltage maybe messed up one of the relays that engages the hydraulics. Any thoughts?
I've heard that if the diode/rectifier in the alternator goes bad it can put a substantial draw on the battery - I'm wondering if this is why the fuse was blowing and why when it was hooked up the tractor acted like it didn't have much cranking power for the last month. I took the alt off and took it to two different auto parts stores and they could find it in their system but both said they didn't know how to test it because it wasn't a standard car/truck alt. Is there a way to easily verify the diode is bad - it has three terminals - the big one that goes to the starter is labeled B+, one labeled D+ I assume might be the diode, and one labeled W I'm not sure on? I think this is the alt (for a heckuva lot less $ than either of the parts houses wanted) - the JCB has a 50HP Perkins in it that is the same as cat and others use in a lot of their smaller skid steers, etc.
Amazon.com: DB Electrical ALU 31 Perkins Engine Alternator For Lucas 24479,24481,24344,24479,2448 ,24481,Jcb 7144 152, 714322 , 714/322 , 714/4 152,714/4 153,Caterpillar 225-3141,225-3143, 3 5-3661: Automotive
Are there not shops around that rebuild fix alts anymore - I asked both Napa and Oreilly and they acted like they had never heard of such but I'm pretty sure that's what we did when I was a kid and dad's tractors had alternator problems.
Does my theory above about the alt match the symptoms/seem likely?
On the hydraulics - I checked all the fuses and they looked ok - but I'm wondering if maybe some wild ac before I disconnected it or using it with lower voltage maybe messed up one of the relays that engages the hydraulics. Any thoughts?
