FD Alt/New Wiring Install (S4)
 

My alternator crapped out on me a while ago and I got an FD Alt. Decided to redo all the "MAIN" power wires. My battery was also shot. So I got a new battery too.

I'm sure you are all familiar with the stock wiring tape up, if not here's a picture:
http://webpages.charter.net/rotary/originaltapeup.jpg

I spent quite a while carefully cutting through all the electrical tape and removing the plastic wire looms so that I could remove all the wires that I needed to. It helped tremendously to remove the Oil Filter and cover with a shop towel, also removed spark plug wires. Here's my break down of the stock wires I was going to replace.
http://webpages.charter.net/rotary/originalwiring.jpg

Here is all the new wires and alternator layed out on my floor with picture inserts for clarity:
http://webpages.charter.net/rotary/wirelayout.jpg

**Note: If you do this and remove your Oil Filter, REMEMBER TO PUT IT BACK ON! I pumped about 4.5 quarts of oil on my garage floor in a matter of seconds after my installation.

I haven't gotten around to cleaning up all the wires, (oil mess and just grouping the wires and running them so they look clean) Also, I left alot of extra wire on all my wires for future recrimps and/or solders.

what did you do about the two exciter wires in that little harness that plugs into the back of the s4 alternator?

Does the FD alt have these? is it a different harness?

Very nice. Id like to see pics of the completed install, as the colored wiring caught my attention, seems far better than the crappy and brittle wiring that I will soon be messing with during future mods.

In the picture you can see I have a constant 12V running from the Battery (+) to the FD harness. As for the wires coming from the car's harness, i believe it's the white/black wire that is plugged into the other FD Harness wire. As for the Black/White wire, it plugs into nothing. I followed this diagram (disregard the green circle):
http://webpages.charter.net/rotary/altinstall.jpg

I've got a few pics, but it looks like ass, you can't even tell where the new wires are. The engine bay is red, and all the wire looms are black so you can't really tell where the new red and black wires are in the picture. When I clean it up I'll take a picture.

Thanks. Even ass pictures are better than none at all. Besides, new wiring is always nice to look at in regards to a clean engine bay.

Oh and may I recommend a nice wash for yoru engine bay? A clean engine is cooler than a cruddy one any day, though you can spend a good chuck of coin at the car wash with there crap, or perhaps soem purple power then a soft wash combined with a brush. Its not much but I cleaned mine to nearly a rebuilt look...so commented a resident rotary builder.

Ok, here's more pictures.
http://webpages.charter.net/rotary/battery.jpg
http://webpages.charter.net/rotary/messy.jpg
http://webpages.charter.net/rotary/altpost.jpg
http://webpages.charter.net/rotary/starter12v.jpg
http://webpages.charter.net/rotary/chassisg.jpg

Like I said, it's still really messy in there.

Still nice though. Makes me want to go buy some blue and black wiring to rewire my car with, as well as some other cosmetic fix's and upgrades for the bay.

Yeah, The wire I got and the connectors I bought came to total around $80. The Battery was like $70. The FD Alt was $185 shipped. Spendy little endevor, but it's soo solid.

Yeah Im gonna be running more stuff than I probably should in my beast. Im happy with my stock fan and everything...but electric seems very nice and then im going to need either a bigger alt....or go nuts and put in a second one to help the first. I justify that by saying im also going to be lookign at an optima redtop battery along with :icon_no2: pushing about 3000 watts of power from my stereo system next year. :smileysex

I'm not running any stereo equipment. I just though my electrical system could benefit from this.

Good thread. Thanks.

Yes, very nice, I also have the FD Alt and right now I only have the stock wires connected up to it. I'll prolly end up going the same route as you.

excellent thread! are you going to cover up the red wire attached to the alt? I could see that maybe being a problem later down the line.

I'd like to wrap all the wires eventually. I guess I'm more concerned with the movement of the wires and them scratching and chaffing on things that I am about heat on that side of the bay.

Very nice. I'm sure you remembered to use dielectric grease on all your connections, right? :)

Of course I did.......
Actually I didn't just cause I needed my car asap to run. I left alot of slack on all wires so that I could redo them in the near future. Will petroleum jelly work? Or is that not recommended?

I feel cooler since I've seen it in person.

Very nice clean work I must say! Adam rocks!

Thanks for making my car feel inferior. Now it wants new power cabling.

IMO, wiring upgrades are a must(even though I'm happy with my extra jumpers).

This should be faq'd.

shit man, i think my wires must be wrong, after my install, car was running great, i did not notice a jump in the power gain, but the car stayed on for 3 hours like nothing, so anways. i parked the car, and when i came down after 15 hours, the car is dead. battery looks totally drained, what could this be. i followed the diagram to the T

stickied!!!!
good write up!!
i just found this...sorry

So without having to redo your wiring which by the way was a great job, is the FD alt a direct replacement on the FC or are there any mods involved? Very interested.

Also why would one want to use the FD alt in an FC? Please advise... :)

The only thing I really had to do hardware wise, mounting the FD alt, was to buy a nut and bolt for the "EarLobe" of the alt. On the FC, the bolt threads into the Alternator, (the alternator is threaded, so there is no need for a nut on the back of the bolt.)
And then I had to splice the wires to fit the FD wire harness. That is the part that seemed to be a hot topic, as it is different for S4's and S5's.

As for why I did it? My S4 alt went bad. I needed a new one, and after reading about the FD I wanted it. It puts out more amperage than my old one. I believe my S4 was rated at 70A and the FD is 100A. All my electronics seemed to work better with the new Alternator too.

hmm sounds good i was actually gonna get a fd alt soon a couple of our members emailed me that they will sell me fd alt lowest one said 80 dollars, im just wondering how much it will cost to put in and how much better r they? i heard ur car lights up like x mas!!! XD cause my headlights looks very dim not sure if its because there weaksauce bulbs or because alt just isnt strong enough to power it all

Thanks for the input.... Looks like I will be buying an FD alt! :)