Alternator conversion question...of a different kind

Stumpalama

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I've been searching and searching on and off 'mud for an answer to this with little to no joy.
Buddy has a '76 FJ40 with a bad alternator and the voltage regulator on the driver's side by the brake MC.
I have an alternator from an '81 FJ40 with an internal regulator.
What are the steps to convert from the Ext to Int regulated alt setup?
Is it straight forward like following along the same lines as an old GM conversion where you join two wires at the old regulator and cap off the other, or is there a good deal of fiddle-f%%king to look forward to?
Thanks in advance!
 
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Its EZ:

1. Remove the white wire with green stripe at the voltage regulator and attach it to the black wire with yellow stripe at the voltage regulator terminal screw. This provides switched power from the engine fuse to the W/G wire.

2. Connect other end of the white/green wire at alternator to the IG terminal of the new regulator.

3. The large white wire with blue strip goes to the B+ lug at the new alternator (just like the old one).

4. There is an L terminal on the new alternator that you can leave disconnected or you can install an idiot light in your cruiser.
 

Stumpalama

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Boy Crusty, that sher is a perty truck in that thar aveeetar...
Why don't you tell us a little about it?:flipoff2:
No worries bro... I'll walk through fire for ya... but a bullet... I'd have to think about it.
:beer:
 

crustyBJ60

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ext to int alt swap...

ok,

lets see if i got this right... (the old set up first) in the '78fj40.

i have 3 wires TO the voltage regulator, WGreen, BYellow and WBlue.

the voltage reg. itself was a little different, WGreen, WRed and WBlack.

the old alt has a 3 wire plug and a B post. the 3 wire plug is F (WGreen) E (WBlack) and N that had nothing going to it, just blank. WBlue was on the B stud.



(the new set up)

new alt has a 2 wire plug, IG and L and a B stud.

i have now connected (direct) the WGreen to the BYellow at the fire wall (the old voltage regulator has been removed from the engine bay). the WBlack is not connected.

at the NEW alt i have the WGreen to the IG and the WBlue to the B stud. the WBlack is not connected at this end either.



that seemed too easy, just wanted to make sure i got it right before i flashed the truck up and lit my junk on fire:D or fry stump's generously donated alternator.

all these wires and spark plugs n' stuff confuse the hell out of me.:confused:

crusty
 
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White black stripe is an optional ground wire to make sure that the external regulator is grounded to the alternator. You can connect it to the alternator case. Everything else sounds good. Fire it up and see if it charges.

I said it was EZ (not E Zed, eh)
 

PabloCruise

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i have now connected (direct) the WGreen to the BYellow at the fire wall (the old voltage regulator has been removed from the engine bay). the WBlack is not connected.

So this will provide switched power to field of the int regulated alternator?

I'm going to do that as soon as my old ext VR bellies up...
 
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So this will provide switched power to field of the int regulated alternator?

I'm going to do that as soon as my old ext VR bellies up...

Basically, it just connects the existing stock alternator field (white/green stripe) wire to a constant switched 12V feed, which is what the internally regulated alternator wants to see. Saves you from running another new wire, but make sure the existing wire is OK.
 

crustyBJ60

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it works, ammeter shows charge!

joy:D

it works, needs a little blip on the throttle to get it to start charging, after that, it's all good. charges right down to idle (well, if you call that spit'n and fart'n idle:rolleyes: ).

got a new belt at napa this am, so it's all good.

thanks, that was EZ .

crusty
 
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Mine's a bit different animal.
I have a 1978 fj40 Kali spec and I'm putting a 2L-T alternator in it from a 1985 turbo diesel minitruck.
There is a plug coming off the new alt with three wires- blue, red, white and there are two terminals E and B

The fat charging wire is easy, it goes to B, but beyond that I have only two wires in the harness that go to the alt....a white w/black stipe, and a white w/green stripe (I think). The white w/green stripe is powered when the ignition is on and I'm pretty sure the white w/black stripe is a ground.

So, the new alt "B" terminal is pretty easy, and from looking at it, the "E" terminal would be a ground. If I had to guess, I would say the white wire from the plug on the alt would go to a battery feedback, and the "red" wire would be the one wanting to see 12v switched power. From there, the blue wire, would be the idiot light.......but all of this is a guess. I haven't fired it up yet for fear of melting the Optima or worse.

Any thoughts?
 
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I'm not familiar with that particular alternator, but if I had to guess, I would bet that it is like any other internally regulated Toyota alternator. It would help if you listed the terminal labels on the alternator for the other connections. All you have listed is B and E.

The alternator would hook up just like the one described above.

B. goes to battery through amp meter and fusible link. Large white wire with blue stripe.
E. ground lug. It may be connected to the white wire with black stripe, but it is not necessary if you have a good engine ground.
IG connects to key on hot wire to energize alternator. See above for using the stock white green stripe wire in this application. Just don't use the ignition coil + wire.
L Idiot light connection. Not needed in a FJ40.
 
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That's just it, the terminals on the alt are not labeled except for B and E.
Those are both easy...the question is the three wires in the plug...the red, white and blue one. I can't find any diagram that refers to what these colors represent. This alt is out of a 1985 2lt minitruck, but my 24v alt out of a BJ74 uses the exact same color codes.

BTW, in the pictures, I have it connected to the white w/green stripe already and it is 12v switch activated...but I did not do anything at the orginal external regulator yet. Ij'm assuming the regulator is the black box mounted on the firewall next/above the heater blower? I was wondering what that thing was... ;)
 
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If it is a stock plug and wires, the color codes will be listed in the Toyota minitruck wiring diagram. There aren't that many possibilities: One is IG and the other is the idiot light, so trial and error should work. You don't want to wire it up to the existing VR because the current on the white/green wire will drop with increasing voltage. You want a constant key on 12V.
 
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Well, with three wires, the trial and error will take longer. But, since none of them will fry anything, I guess it doesn't matter. I'll pull the old reg out and do the wire connect you are referring to.
Here's a thought, since my understanding of the three wire is 1) constant voltage 2) battery feedback 3) idiot light....wouldn't it just make sense to combine the battery feedback and the constant voltage wires? I mean, it seems like both of them are providing the exact same information to the regulator. In some of the diagrams, (colors are different) it appears that the B post not only feeds the battery circuit, but it also directly feeds back into the regulator. I'll try to post of a schematic of this.
 

PabloCruise

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Basically, it just connects the existing stock alternator field (white/green stripe) wire to a constant switched 12V feed, which is what the internally regulated alternator wants to see. Saves you from running another new wire, but make sure the existing wire is OK.

Thank you sir!
 

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