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saturn alt help/question


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so got it all bracketed an mounted, belt on...started truck, voltage read 11.75, never changed versus engine rpm, infact dropped involtage to 11.39 both read at battery and out put of alt....when i take a readi ng at the output stud it appears to read the voltage of the batt...(ie...back feading readin through harness...) its the same at batt terminals as the output stud...battery started at 11.79 before even starting...jumpered yellow to white, white with red to white with black at vlotage reg, at saturn plug i hooked the yellow to the s or sense wire and the white with black to the l for light/lamp cicuit...f (feild positive) wasnt used nor was p half wave rectified.... seems it aint outting out any voltage any suggestions...

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It reads the same, at the out put of the alt and at the batt and will fall along with the batt...started at high elevens and fell to 11.39. Every alt i ever had on other vehicles at least put out 13.5, i tool it back out and will have it tested, trusted the kid i bought it from, he said it was new, got here and it had obviously been installed..emailed him and he says "oh i put it on and took it back off when i, uhhhh, wrecked the car..yeah wrecked the car" anyway shoulda got it tested first buut still looked real new just obviously not brand new....



I still am questioning the wiring of the plug the plug i got for it from napa, it had three wires, large one is S, two small ones, L which i hooked to black with white, and a f ..not used according to the walk through, i hooked the yellow to S , as described and it didnt work at all....tested it and its receiving 12 v when the ignition is on....read on 510realm...dude doing a swap with a 2 wire plug, used the f terminal to send the yellow, didnt use the s , as there was not a wire for S anyway...tried that still no charging of out put..still saw 12 v with ignotion on when in tested the f location too...any body used the three wire plug on this swap and know the proper wiring of it... slodt provided the original tech for the wiring....i remeber on here another article about the swap that talked about the plug i have and i cant find it now the search is a little different with new ratsun...


anyway, took the alt back out to get tested and see if im sending hatemail to thi s kid i bought the alt from....when i find out the alt. is bad i will return the wiring to slodats diagram and try again hopefully with a working alt... man the thing is so quiet now with that alt on there.. the old datsun one i had howled like a mother.... any help with that plug wiring would be helpful... thankss...

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Not sure which saturn alternator you have(and i could not tell the difference), but i do know that certain ones are controlled by the cars(saturn)computer to complete the wiring circuit to the regulator. probably just controlling the ground to the regulator, but i dont know, maybe that is what the third wire is all about?


Good luck

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So took that fawker to Car quest today....yes its bad.....dude says thats wierd it wont even trip the charge light meaning not worn out ...smoked...thanks ebay thats twice....not gonna buy motor parts off ebay anymore... got screwed on a four barrel for the blazer and now this ....although i feel better knowing i only got 30 bux in this one.... the carb i lost 180.00....so now i got a new one and will try again would sure tliketo verify the wiring to excite the alt with my three wire plug.....Im gonna assume slodat is right if i cant get some more solid info....anybody out there with a suggestion post it up here so i can read it ... gonna try and track downa wiaing diagram for the saturn too to see if i can determine it ....

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1996 saturn....95 amper .....common swap ... ijust seem to make it diffficult....blazer news.....blew lower radiator hose off ...when it rains it pours.....


new radiator had smaller nipple on lower inlet... tried the old squeze the hose down to fit... lasted for a bit.....didn't know they made these but, theres hose reducers for just this instance.... learn something new everyday....

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ok fixed the blazer's radiator hose, so far so good on that one... now back to the saturn alt.....


this is the alt with the bracket on it... to be honest now that i got it in there I dont think I needed to grind on it at all....



both of the alts before I shimmed the pulley correctly....ended up using a 3/4 shim but it all depnds on the pulley you get...mine was off a late modelish gm alt...



after the 3/4" shim installed... the first pic was the 1/2" ...it's till not perfect when its mounted up but its with in 1/16




side by side comparision of alt sizes and where my new bracket was to be fabbed and how long i would need it....made my bracket so i could use the factory upper mount without mod or cutting...probably could make it different a little cleaner but the brackets I made to attach are good just not as pretty as I'd like...needless to say I forgot to take a pic of them when it was installed... when I re-install tonight I will take a pic....needed a little more grinding anyway....




and a pic of the old droning alt that got yanked.. yeah i dunno just thought it could use some face time...



still wanna double check the wiring with anyone that has used it the plug is in the alt in the first pic.....

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that third pic is a good pic of the plug ...the large guage wire is the s and the other two are the f and l terminal....like i said if no one responds im going back to the way slodats said to do it.... s to yellow and l to white with black ...and if it burns my alt up you all owe me two dollars each...

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taa daaaaaaa....new alt, slodat wiring and bracket refinement and boom 13.8 at low idle with lights, wipers, heater on high even threw in a blinker for good measure...lights burn brighter than ever, low rpm accel stumble, gone.....runs quieter than ever, red top saved from eternal discharges of death...pics to follow when I load them up at work tomorrow...


quick 521/saturn alt facts... used stock length belt 15350, tried half inch shorter 15345 as suggested, was to short to even get it off the block, stock mid 80's gm pulley with 3/4 inch spacer, no grinding of steering parts for clearance, used sheet metal stamped bracket(ground down but probably not even needed...) three wire plug from napa for 1996 saturn 1.9l(same year was used for alt.) S to the yellow as confirmed, L to white with black....volt reg jumpers yellow to white, white with black to white with red, ignition light works on dash during start up, might try a smaller pulley at some point as at real low idle dips to 13. and lights dim a little...thanks to anyone that helped answer questions along the way....not bad for only being able to put in a hour here or a hour there while daughter napped...straight through probably could been done in a couple , three hours... spent 40 mins refining bracket that you cant even see...and assuming you dont have to take out the alt twice due to being bad from ebay and re wiring it twice..


Bracket facts 4.5" long with one 5/16 hole and one slotted 5/16 hole an inch long at each end...use nylocs to ensure bolts dont loosen form vibration...not the best but i wanted to retain the factory bracket, no turn buckle, just jam nutted while wife put tension on it with a breaker bar...

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so heres the final pics of install..


pic of the bracket to retain the factory adjusting bracket....



different angle...front view



voltage at low idle with everything i could find that wwas electrical on....




some pics of it with the lights on ....way brighter , i can see my turn signals now and the wipers are gonna wear out my new blades if they dont slow down....







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sure bring it over gotta do my buddys, but it's not a priority his truck has a laundry list of things to complete...plus I'm running his radiator......can't wait to hook up some hids in my low beams....ordered the lens today from hella....anynody got a good radiator then wanna part with it....gonna try and make one out of my old one and a 510 radiator...

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what do you do with the 3rd wire from the saturn alt? It wasnt mentioned. I assumed the OUTPUT wire was a big 14 gauge to the starterlug plus the stocl red/wht wire.


yes 510 and 521 radiators are the same. The shop I yook it to pc one together from 2. said the top was bad in one(i dont know how they can see this) I just see leaks but he said he can tell if the metal is still good or not.



My computer is using a old browser so i dont think i can get PM messages . so send 1 OM and also post here till i figure this Browser thing out.

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