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Looking at an alternator upgrade


dozenhundred

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Hey all,

 

I'm getting kinda tired of the H4 headlight conversion overwhelming the little 35 amp alternator at idle. I have read on Datsun1200 about conversions and seen some posted here on Ratsun, but not specifically for the A12. Datsun 1200 claims the lower radiator hose is a problem with the bigger hitachi unit. Has anyone done this or some other small case alt. I wouldn't mind getting rid of the seperate regulator also. I saw a picture of Morrisun's smurf that looked like the bracket was modified but couldn't tell if it was a different alt. My alt bracket is wallowed out anyway and I have access to tools to build a new one. Looks like it would be pretty easy to lower the bottom mount down some for more room.

 

Any suggestions? ;)

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I'm running the 40A unit out of a 210 in one of my 1200's. There is enough meat in the alternator bracket that bolts to the block to slot or re-drill the mounting holes. This will lower the alternator enough to clear the radiator hose.

 

For wiring the internal regulated alternator I only hook up the charge light and let the regulator self sense. Self sense mode increases the output voltage ~.5 volts over having the sense wire connected to the alternator output. The extra .5 volt is welcome when you are trying to get nice white lights with your H4 setup.

 

You have wired up a new harness for the lights using 30A relays that picks up power from the alternator output and returns the negative to the alternator case haven't you?

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I'm running a compact Nippondenso "1-wire" alternator on mine. Half the size, half the weight, more amps, and only cost $87 shipped.

 

It does away with the external regulator, and is a straight bolt-on. :)

 

normal_photo2.jpg

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Datsun 210 ame with 50A or 60A unit. It is too large to truly "bolt on" the early A12, but you can modify the bracket as Gary P suggests.

 

But it weighs more than the 1200 stocker, so can you consider it an 'upgrade'?

 

Morrisun used a Mazda alternator, totally stock, didn't change the pulley or anything. It is 60A and lighter than the 1200 unit. Available from the pick-n-pull for $12.50 (I saw several last time I was there, it is from 1980s Mazdas). He did modify the bracket similar to what Gary is saying. Either way you will need a slightly larger fan belt.

 

Datsun 1200 comes from factory with heavy gauge wire on the high beams, but the extra current may damage the headlight switch. So add a relay. This will also eliminate all the connections in the stock harness, adding reliability. You can cut the headlight harness, and solder in a wire over to the alternator BAT terminal. Use a $2 Nissan relay and more importantly a 30A fuse right at the ALT. Do the same for the Ground wire, cut it and solder in a splice wire (same gauge) over to the alternator E (earth/ground) terminal.

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I'm running a compact Nippondenso "1-wire" alternator on mine. Half the size, half the weight, more amps, and only cost $87 shipped.

 

It does away with the external regulator, and is a straight bolt-on. :)

 

normal_photo2.jpg

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I'm running a compact Nippondenso "1-wire" alternator on mine. Half the size, half the weight, more amps, and only cost $87 shipped.

 

Thanks guys,

 

Anything known about what that Nippondenso unit comes from to help finding one? Or the Mazda unit mentioned earlier? Sounds like my kinda desire.

 

I did indeed upgrade the headlight wiring. I bought a kit from Daniel Stern Lighting. Came with the relays and all sockets. I sourced the wiring local. The lights were in the car when I bought it running on the stock wiring. Needles to say the fuse box was melted. Bought a new fuse box off fleabay and installed the relays/upsized wiring.

 

Nice now, but they do dim a little at idle. I understand the H4's can pull up to 30 amps, so with the stock 35 amp alt. it is indeed iffy. Hence the upgrade idea.

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Anything known about what that Nippondenso unit comes from to help finding one?

 

It comes from a fork lift. :P

 

But for "1-wire" operation (as in just one big wire from the hot post to the battery and/or starter, uses none of the factory wires) it has a special "self-exciting" regulator installed in it. I get mine here:

 

http://cgi.ebay.com/ebaymotors/ALTERNATOR-CHEVY-MINI-DENSO-STREET-ROD-RACE-1-WIRE-8162-_W0QQcmdZViewItemQQhashZitem20b881980bQQitemZ140534454283QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories#ht_2649wt_1165

 

Bought 3 so far, all worked like a champ. :cool:

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I love the look of that Nipondenso.

 

I love 'em. I'm not a big stereo guy, so I don't need more than a 50-55amp alt can produce, so all my cars are getting these from now on. :cool:

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The altenator I used on Smurf is from a Mazda RX7 (S4 1986-1988) I remove the jumper wire, unwrapped the harness, about a foot and removed the wires not needed and terminated the ones in the splices. The plastic connector that is in the back of the stock alt. slips right on to the rx7 alt. and only one wire is used in this connector, the other was already cut out. These are 70 amp alternators. I bought a head light relay kit from Black Dragon for a 240Z, it's plug and play no splicing-$29.95 plus shipping. I wanted to replace the orginal wiring to the head lights any way! Mine came with a double sheeve pulley, but the single sheeve lines up the same. If you need bracket to redrill for your 1200 let me know. The 1200 site has wiring diagrams for this change.

P6150422.jpg

P6150425.jpg

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So morrisun, the Mazda alternator requires no wiring changes, correct? That alternator was also used in Mazda sedans and trucks from the looks of it.

 

If you fit an internally-regulated alternator that uses the stock T-connector, just unplug the original voltage regulator and jump one wire.

 

Either buy one of these, and plug it in where the external regulator was:

14739.jpg

 

Or do what I did which cost nothing:

7441.jpg

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  • 2 months later...

Hey all,

 

I'm getting kinda tired of the H4 headlight conversion overwhelming the little 35 amp alternator at idle. I have read on Datsun1200 about conversions and seen some posted here on Ratsun, but not specifically for the A12. Datsun 1200 claims the lower radiator hose is a problem with the bigger hitachi unit. Has anyone done this or some other small case alt. I wouldn't mind getting rid of the seperate regulator also. I saw a picture of Morrisun's smurf that looked like the bracket was modified but couldn't tell if it was a different alt. My alt bracket is wallowed out anyway and I have access to tools to build a new one. Looks like it would be pretty easy to lower the bottom mount down some for more room.

 

Any suggestions? ;)

 

How are you Kelly? Long time no talk. So hows the 12 looking so far? Any pics?

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  • 1 year later...

Do you have more details about the RX7 mod? more details on the rewiring and install? I have a 83 maxima wagon needing a real charging system.. I want enough power on hand to power trailer lights and brakes, etcetc.. 70A sounds like a better solution. Do you have any dimensions for those posts?

 

also the pulley looks nice and small - did it come that way? is it good at low idle?

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Maxima came with 60 amp alternator, you may what to look for one that puts out 100amps because of your demands on your charging system. Some of the mid 90's Maxima's had 100, 110, and 125 amps, I don't know if they would bolt in to your car or not but may be the simple way, you can take measurements off of yours and check out the wrecking yards for one that would fit.

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So morrisun, the Mazda alternator requires no wiring changes, correct? That alternator was also used in Mazda sedans and trucks from the looks of it.

 

If you fit an internally-regulated alternator that uses the stock T-connector, just unplug the original voltage regulator and jump one wire.

 

Either buy one of these, and plug it in where the external regulator was:

14739.jpg

 

Or do what I did which cost nothing:

7441.jpg

GG does this one jumper keep the alt light functioning?

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Yes, it jumps the Lamp circuit to the L terminal of a circa 1980 Datsun LR150 alternator (50A).

 

For other alternators you will need two wires, one for L and the other for S. Or just connect S to A directly at the alternator. See http://datsun1200.com/modules/mediawiki/index.php?title=Hitachi_LR_Alternator#Wiring

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