Toyota 3B alternator

[KIWIALEX]

Bit of an cross over here. I have a Series 3 Land Rover fitted with a Toyota 3B. Engine is a fresh rebuild, and the alternator has been recently bench tested etc and in perfect working order (kind of) the external regulator hasn’t been tested/used properly since it was last tested properly over a year ago at the same time with the alternator

My issue is the alternator for some reason isn’t charging the batteries. At idle the voltage is roughly 22-23v, I found that the charge bulb in my dash was blown so thought that may have to something to do with my issue.
After replacing the bulb I turned the key to ignition (engine still off as it’s push button start)

And the bulb didn’t glow, I then attached an earth from said bulb to the steering shaft and bam the bulb glows bright. I had a Poke at a few things and did a continuity test on the regulator and it was good.

Looking for ideas on what it could be.

Cheers

 

[stevebradford]

Your alternator has three wires it needs to work:

1 Charge wire. This one will be connected to battery power all the time.

2 Field wire. This one’s neat, power comes from an ignition source and builds a magnetic field in the rotor generating power.

3 Sense wire. This wire will let the regulator know how much to output, max charge for low batteries or trickle for normal running.

You problem sounds like the alternator is not charging at all. if you are convinced your alternator and regulator are good then the issue will be a wiring connection issue with either 1:battery wire or 2:field wire.

Start with the easy one I believe on yours the 1:battery wire will be a thick wire that lands on a stud ontop of your alternator. Check for battery voltage there.

Next is going to be more chasing 2:field wire will start at the batteries go through ignition wiring or relay then to the voltage regulator. I assume you’re running a 40 series wiring harness due to the external regulator? Here it’s Black/Yellow fed from engine 15amp fuse. And then White/Green between the regulator and alternator.