Regulator / Alternator help..

[[JP]]

Hi all..
So I finally driven my truck for the first time, took it to the inspection here in the UK so I can now ask for UK plates.
however.. it broke down on me on way home.

As background, I have a Buick 350 engine with a TH350

the inspection garage is just down the road from me, on one of the roads, which is a bit longer I stepped a bit more down on the pedal as got used to the feel of the truck, nothing stupid though, smooth accelaration to build speed.
and the truck started to missfire.. and then eventually died. 50yards from garage! Battery was flat as a pancake. called one of the guys and they came out with a starter pack, started the truck...drove the rest slowly, we did the tests, truck running fine while it was in there, once turned off, battery flat, starter pack again and off I went back home.

Drove back home.. slowly slowly..got to that same road, same thing happened. when i tried to build speed, misfire, died..battery flat. called a friend he came out jump leads and off I went home again, this time without trying to build up too much speed.
Got home, reversed to the drive, sat there for a bit and then the truck starts to misfire again...and died.

this time I managed to start it again and tested the following with a multimeter:
Does this mean alternator ****ed?at battery terminals I had:
Engine off - 12.57
Engine running - 12.67
Engine running and lights on - 12.50
After all these tests engine off and got 12.48 at battery terminals.

Could this here be the reason why it kept missfiring when asking for more speed?

Then a friend suggested to test the input at the regulator, output and in at the alternator. that's when all went wrong!
When measuring terminal 2 on the alternator I slipped into the engine, it touched terminal 1 and puff!!! the fans stopped working (i have twin radiator fans connected to terminal 1 on the regulator) I'm guessing I've blown the regulator? as at terminal 1 and 2 of the regulator there's a big fat zero...


here's some diagrams I've done.
how everything is connected now....

On the standard installation I found:

• the brown wire from the Gen dash light has been cut in the engine bay (was probably connected to the original regulator, bottom right of diagram - BRN)

• the wires that would have connected to oil sendor, thermo sender have been cut and not connected. (top right plug - DG - DBL and LG)

• then from the same plug there's 2 wires that would have gone to starter motor, with one of them then going to coil ( P and PPL)
  instead they have bypassed the starting motor and put one straight to coil

• Pink is straight to the coil

• PPL straight to starter motor.

and here's what I have:


And now looking at this and the original wiring diagram.. was the truck properly wired?
I have the terminal 4 from the regulator going to the coil... but on the original wiring it goes from regulator terminal 4 to the gen dash light wire (which is the brown wire that has been cut in my engine bay)

So on another forum I was told I could get rid of the regulator and get an alternator with regulator included, and to do the wiring like this:

• Output from alternator fed straight to battery positive, or terminal on starter motor that goes to battery.

• Wire from battery to ignition switch.

• Wire from ignition switch to alternator, via charging light on dash.

• Wire from ignition switch to coil and fuel pump.

So I done a new drawing:


the bit that was confusing me was "wire from ignition switch to alternator via de dash light"
but without touching the original wiring this might be the way I've done? there's 2 wires from ignition that go to the gen light though.. the pink (directly to one side of the bulb) and the brown with white dash (as it connects to same spade connector as the brown that comes from the bulb)
but what do I connect to the second terminal on the alternator? I think its battery as well? didnt draw that bit...

very confused about this! help please....

oh.. and I had a look on rockauto website, im guessing these will do?

regulator if I go with the setup I have -
https://www.rockauto.co.uk/catalog/m...nid=466&jpid=0

or alternator with built in regulator - ACDELCO 3342112A; Amps: 63; Pulley 1V; External Fan; Internal Regulator; Clock: 3:00; w/o AC; 334-2112A; 6Y1; 0050A
https://www.rockauto.co.uk/catalog/m...nid=457&jpid=6

[PGSigns]

One thing I see is the fans hooked to what I think may be the field wire off the regulator. That may be a problem. If anything it should come off the hot lug on the horn relay. If you go to a one wire alternator the wire off the alternator would go tot he battery. There should be a wire from the battery to the horn relay. A wire off the horn relay to feed the fuse box. The power to the key used to come from the fuse box. I would run a wire off the switch to the coil and to a relay to drive the fuel pump.
Jimmy

[[JP]]

There's no horn relay, that has been hacked off.
The thing with the fans was that they were instantly on as soon as i had ignition on... obviously when I slipped into the engine and touched both terminal at the alternator the fans stopped working... that's why i think I've blown the regulator as there's no voltage at terminal 1 and 2

[vince1]

I think if your wiring has been extremely altered it might be easier to just put on an internally regulated alternator, either si series or CS130. Brown wire from lamp, if it works, to terminal 1 on Si or L on CS130. But there are people much more knowledgeable than me who have covered the topic in greater detail in many threads over in the electrical forum.