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Bosch Alternator Wiring confusion


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I've been trying to get some assistance with this in the Historical section to no avail, so I'll try here...

 

I have a Bosch internal voltage regulator alternator I'm putting in my FF-1. I cut the wires for the voltage regulator which ended up leaving two wires, one black/white and one white red. But I'm not sure which ones go where into the plug on the Bosch alternator which has a yellow and green wire:

 

alternatorwiring.jpg

 

Does anyone know which I should plug into which?

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You sure thats a Bosch? Sure looks like it says Hitachi on the back. I tried to find you something but had no luck. Whats the model # of that unit? I think one wire goes to a wire thats hot in run at the key and the other goes to the light on the dash. Big red one to the battery and I think there is a male spade connector somewhere that goes to ground.

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Ya, you are right, it is a Hitachi. Came in a Bosch box though :P Sorry about the confusion.

 

Bosch AL241X

 

 

 

is the part number that was on the alternator before I took the sticker off. Trying to figure out which hitachi it should be...

 

It is a 60 amp.

 

http://www.partsgeek.com/mmparts/alternator/subaru/standard.html

Edited by Kostamojen
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Hi. That alternator looks like the same one that I have on my 91 Loyale SPFi ea-82. From looking at mine it would be the thicker wire(your yellow) would be BW and the thinner wire (your green) would be WR. Great job on your FF1 btw. Can't wait to see the final on it. Been a faithful reader of your thread since the beginning. Don

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Hi. That alternator looks like the same one that I have on my 91 Loyale SPFi ea-82. From looking at mine it would be the thicker wire(your yellow) would be BW and the thinner wire (your green) would be WR. Great job on your FF1 btw. Can't wait to see the final on it. Been a faithful reader of your thread since the beginning. Don

I'm fairly certain you are correct.

 

I think my one concern right now is whether the white wire (BAT) needs to cross over to the Yellow or Green (BW or WR) at any point...

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I think y'all have it right. No I don't think it ties to either of those 2 directly. Take the Heavy White wire to the battery then a pigtail from the battery terminal to the fuse box at terminal #2 . I would put a circuit breaker in that line. Your schematic shows a 70amp load at terminal 2 so a 70 amp cb should be good. I'm not real sure of that though, I don't think it would ever see that at one time maybe a 60 or even 50 would be better. Make sure you use a proper size wire there. Might be a good idea to let someone else chime in on that thought. If you do, put it close to the battery end. And I agree I have just about read your whole journey, really sweet project. Takes a lot of determination to see such a long project through. A lot of people would have tossed in their hat or passed it on by now.You are just about there now.

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Without that jumper it looks like you should have all kindsa stuff not working. Wiper, washer, horn, lights, etc. To bad my father in law moved to Yreka. He is a wiz at this kind of stuff and could have hooked you right up. They Left Roseville a couple of years ago.

Edited by bigjimd
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After going over the previous posts here it looks to me you guys are on the right track. The only thing I noticed that should be done is a fuse needs to be placed in the main alternator output lead that ties to the battery in case the main lead gets shorted at the alternator somehow. The fuse may need to be around 80 amps or slightly more than the rated output of the alternator.

 

The 'S' lead of the alternator is the battery sense lead which needs to tie to the battery through a fairly small fuse. It normally uses the b/w wire like you stated. It senses the battery voltage so the internal regulator will know how much current to produce to keep the battery charged up.

 

The 'L' lead is the lamp lead that normally ties to the w/r wire which is connected in series with the battery warning light and then to switched ignition power (the ignition switch). The lead supplies power to the exciter field of the alternator which gets the alternator action started.

Edited by Cougar
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