JCB 1400B issue

[Guav444]

Hey everyone, just got my first piece of heavy equipment, a big old JCB 1400B.

It's a bit of a beast, and I'm trying to figure out some wiring stuff.
I'm having trouble with the voltage stabilizer. Is that thing built into the alternator, or is it a separate box somewhere?
The alternator has like 3 or 4 wires coming off of it, so I'm totally lost. Any tips on what to look for?

 

[digdumpdrive1263]

Okay, so on the 1400B, the voltage regulator is usually part of the alternator itself. Those 3-4 wires you see are for the battery, the field, and sensing what's going on. If you're having trouble charging, start by checking the voltage right at the alternator. Some versions might have a separate regulator box close to the alternator, but usually, it's inside the alternator

 

[J3rryking]

hi @Guav444 the 3-4 wires on the back are usually B+ (big wire to the battery/solenoid), Ground (often through the case, but sometimes a wire), Ignition/Exciter (a small wire to 'wake up' the alternator), and sometimes a Sense wire that checks battery voltage directly.
The ignition wire is usually the problem.

 

[Alan]

Make sure to follow the wiring harness back to the dashboard. Some 1400Bs have inline resistors or diode blocks hidden near the firewall, and these can fail, causing issues with the charging system.