Alternator question
05-30-15, 01:38 PM
#1
Alternator question
i recently bought a FD alternator and banzais dual v belt pulley to go along with it
i drilled the pulley out, but i apparently didn't get the drill press dead center and it has a bit of a wobble all together, its nothing major, but its visible spinning it by hand
should i go with it? or find another pulley?
i drilled the pulley out, but i apparently didn't get the drill press dead center and it has a bit of a wobble all together, its nothing major, but its visible spinning it by hand
should i go with it? or find another pulley?
05-30-15, 07:01 PM
#4
Alternator question
actually, i made up my mind, gonna do what i should've done in the first place, gonna goto the machine shop, have them drill it out bigger and press a bushing in so the ID is 17mm
that way my car isn't down for a week incaseshit
that way my car isn't down for a week incaseshit
06-02-15, 08:08 PM
#7
so instead of making another thread, I have a wiring question now for the FD alternator
I printed off this
I do understand the schematic, but, my confusion is this....does the FD alternator NEED 12V constant power on terminal S? Why can't I get away with just using the stock s4 wiring where terminal S would be a switched 12V from the ignition switch? IMO I would rather have it switched so I don't have to worry about a drain on the battery, I don't understand what the difference would be as long as theres 12V while the ignition is in the on position? Can someone elaborate? If I have to snip wires to make it work it won't break my heart much, but if I can avoid it, why not?
EDIT: now that I think about it, I guess that terminal S would actually be a sensing wire, and that it may not charge properly because the reading through the ignition switch would be a different reading than right from the battery.....am I thinking correctly?
I printed off this
I do understand the schematic, but, my confusion is this....does the FD alternator NEED 12V constant power on terminal S? Why can't I get away with just using the stock s4 wiring where terminal S would be a switched 12V from the ignition switch? IMO I would rather have it switched so I don't have to worry about a drain on the battery, I don't understand what the difference would be as long as theres 12V while the ignition is in the on position? Can someone elaborate? If I have to snip wires to make it work it won't break my heart much, but if I can avoid it, why not?
EDIT: now that I think about it, I guess that terminal S would actually be a sensing wire, and that it may not charge properly because the reading through the ignition switch would be a different reading than right from the battery.....am I thinking correctly?
Last edited by lduley; 06-02-15 at 08:14 PM.
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06-02-15, 11:36 PM
#8
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S and B go together...on an S4.
I just made a female spade to a eyelet.Put the female spade on S and eyelet to B(post on alt)
You can then run a female/male spade jumper to L on the harness and L on the FD alt.
Funny thing though when I ran Without L hooked up,I still got a Reading on my dash.
I just made a female spade to a eyelet.Put the female spade on S and eyelet to B(post on alt)
You can then run a female/male spade jumper to L on the harness and L on the FD alt.
Funny thing though when I ran Without L hooked up,I still got a Reading on my dash.
06-03-15, 06:18 AM
#10
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Good morning!
S- I believe is to excite the alternator to allow it to produce power.
Now,If memory serves me right Akagi's White Comet has another Diagram that he produced to install the FD Alt and he puts the S terminal to a switched power source.
When I ran the FD alt on the S4 system,I encountered a bit of "funky ****" and the alternator would not excite until the car was "lightly gunned" at start up and revved over 2500 so it could spin enough to catch the Point that the ALT would kick in and start producing power.
You could see the Voltage being low until you hit the gas and then it would shoot up to 14 volts and stay there.After that initial blip of the throttle the electrics were good.
*One time I did not Blip the throttle and the car died after about 20 minutes of idle.
This was with S and B hooked up and NO L.
S- I believe is to excite the alternator to allow it to produce power.
Now,If memory serves me right Akagi's White Comet has another Diagram that he produced to install the FD Alt and he puts the S terminal to a switched power source.
When I ran the FD alt on the S4 system,I encountered a bit of "funky ****" and the alternator would not excite until the car was "lightly gunned" at start up and revved over 2500 so it could spin enough to catch the Point that the ALT would kick in and start producing power.
You could see the Voltage being low until you hit the gas and then it would shoot up to 14 volts and stay there.After that initial blip of the throttle the electrics were good.
*One time I did not Blip the throttle and the car died after about 20 minutes of idle.
This was with S and B hooked up and NO L.
06-03-15, 06:56 AM
#11
Alternator question
well i guess the worst i can do is try it and see what happens, electricity wise i don't see why it won't work normally if S is hooked up to constant 12V or switched 12V from the ignition switch, as long as it has 12V before and while its running, which the ignition switch supplies running or just on the ON posistion
06-03-15, 08:06 PM
#12
This:
GuiltySoul, I want you to IGNORE everything else in this thread except for what I'm about to show and tell you. When I did mine in 2008, there seemed to be much confusion about how to wire it correctly, and that seems to still be here. As such, I found that the diagram in the FAQ was wrong and made my own which proved to work correctly.
There is NO cutting needed to use a FD Alternator in your S4 car if you have a FD Alternator pigtail. You will need to upgrade the Output Cable (you called it B+ Cable) to 4awg. Visit your local welding supply store such as DeLille and ask for 3ft of 4awg Welding Cable and two cable lugs. This will be more than enough. I went there yesterday and it was $1.58 per foot, compared to $4 for battery cable at Oreilly Auto Parts.
Follow this diagram to the letter and it will work correctly. Rev it to ~2000 rpm to wake it up if your alternator is a tad sleepy like mine was
While it is not necessary to the alternator's operation, removing the old output cable is a wise choice to prevent shorting out against the UIM. De-loom it back to the fuse box and you'll see that it's T-spliced into the fuse panel to battery cable. Snip it off with diagonals and cover it with electrical tape and maybe some split loom too.
The end result will be that you'll have an 8awg cable from the fuse panel, a 4awg cable from the starter (stock is black w/yellow stripe) and a 4awg cable from the alternator, all converging at the battery's positive terminal. Using marine-type battery terminals with wing nuts to attach the lugs is probably a good idea too.
If you're feeling ambitious, now would be a good time to replace all of the battery cables. Chances are your battery cables are not in great shape and have several breaks in the insulation like mine did. Aaron Cake has a great write-up on doing this correctly, using welding cable. Only thing I can add to it is to be sure to put a band of red electrical tape around the positive starter cable on both ends so you don't mix them up.
There is NO cutting needed to use a FD Alternator in your S4 car if you have a FD Alternator pigtail. You will need to upgrade the Output Cable (you called it B+ Cable) to 4awg. Visit your local welding supply store such as DeLille and ask for 3ft of 4awg Welding Cable and two cable lugs. This will be more than enough. I went there yesterday and it was $1.58 per foot, compared to $4 for battery cable at Oreilly Auto Parts.
Follow this diagram to the letter and it will work correctly. Rev it to ~2000 rpm to wake it up if your alternator is a tad sleepy like mine was
While it is not necessary to the alternator's operation, removing the old output cable is a wise choice to prevent shorting out against the UIM. De-loom it back to the fuse box and you'll see that it's T-spliced into the fuse panel to battery cable. Snip it off with diagonals and cover it with electrical tape and maybe some split loom too.
The end result will be that you'll have an 8awg cable from the fuse panel, a 4awg cable from the starter (stock is black w/yellow stripe) and a 4awg cable from the alternator, all converging at the battery's positive terminal. Using marine-type battery terminals with wing nuts to attach the lugs is probably a good idea too.
If you're feeling ambitious, now would be a good time to replace all of the battery cables. Chances are your battery cables are not in great shape and have several breaks in the insulation like mine did. Aaron Cake has a great write-up on doing this correctly, using welding cable. Only thing I can add to it is to be sure to put a band of red electrical tape around the positive starter cable on both ends so you don't mix them up.
06-03-15, 09:50 PM
#13
Alternator question
so then my idea is correct from what i read and see in the original diagram, just take the terminals out'vs the stock s4 alternator plug, plug them into the FD alternator, and i should be done.....or am i still missing something?
06-04-15, 09:22 PM
#14
Alternator question
welp, got the pulley back (which was done amazingly, looked OEM) hooked it up to the normal s4 harness (good thing i got the s6 pigtail, stock s4 wires are WAY to short) fired it up, and it came alive, power windows work better, the headlights are brighter, was completely worth the $160 i put into it all together
one note i'd like to add for future searching purposes, and i don't recall reading it while doing my searching on here is...
the front engine lift bracket MUST be loosened and tilted out've the way for the alternator to line up to the stock s4 tensioning bracket
one note i'd like to add for future searching purposes, and i don't recall reading it while doing my searching on here is...
the front engine lift bracket MUST be loosened and tilted out've the way for the alternator to line up to the stock s4 tensioning bracket
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