Toyota voltage regulators... Two of?

[Finnius]

Hey folks,
I have an old toyota 4runner that i am fixing up at the moment.

I have been told that the alternator in these toyotas has an inbuilt voltage regulator and mine has a little plug at the back with a few wires that come out of it along with the main positive charging cable.

However, there is also a voltage regulator box bolted to the inner fender that has many wires that come out of it.

My question is; why is there two voltage regulators and how are they setup (i.e what controls what)? What controls the charging of the battery? What on earth are all the different wires likely to do?

I am not looking to overhaul the system, although i am putting in a new higher output alternator - i just need to know how the regulators work so i can fix them if something goes wrong way out bush.

Thanks!

[bee utey]

Considering the age of the thing it's likely the original external reg alternator has been replaced with an internal reg one. I know that when I asked our local auto sparkie for a direct replacement alternator for a similar age Jap vehicle, he could only supply internal reg types. In my case I simply connected the warning light wire from the old external reg to the relevant wire from the alternator, bypassing the old reg. I've no idea exactly what I did (too long ago) but it just involved a bit of work with the multi meter to work out which wire was a voltage sense, dash light etc. and wire them to the alternator supplied. If you are fitting a replacement alternator with internal voltage reference then you only need the main battery cable and one for the dash light. Whoever supplies your alternator should be able to advise the correct wiring.

[Finnius]

Yeah thanks.
No it looks like it is the old type alternator with external regulator.
What threw me is that apparently toyotas with the 22R engine after 85 have an internal regulator. Mine is an 89 but it has an external one.
I have another 89 hilux with 22R and it is the same with the external regulator, so it appears that in Australia they continued to use external regs whilst the US swapped to internal in 85... :confused:

Anywho, once i get a bracket sorted i will swap it over.
I think there is 3 wires in the back of the new one; ignition, sense wire, and charge light.
It will actually be nice to get rid of the external voltage regulator and associated wiring. Although now i might have to carry a spare alternator out bush instead of a voltage regulator!

On another note, i presume my 94 3.9 disco has an internally regulated alternator?