ALTERNATOR WIRING 101.....................

So my alt. is done after 10 years of abuse and a friend is going to warranty it out and step it up to a newer 90 amp Denso so what's the best way to wire it in. Currently it goes through the column like factory.........Thankxxx.................

http://radiantmoons.me/denso-alternator-...lternator-3-and

Google helps

Tex

Dim if you haven’t allready done it yet. I would bypass the Alt wire wear it goes through the bulk head connector and bypass the factory amp guage

That was supposed to be Dom. Stupid phone. Lol

doesn't Andy's brackets have wiring instructions.
run the alt output to the post on the starter relay and then to the battery.
run a reference 12v source to the alt plug and maybe a switched 12v wire too...
it's pretty simple, wired this way the ammeter won't be accurate. so maybe run an aftermarket voltmeter in the car...

Did that years ago............Thankxxx guys and I do have a volt meter but me and a drunk friend wired some of this stuff 15 years ago and w/the key in the run position it charges but when I click it back a notch, no charging so part of it goes through the ign..........

I would run a 6 gauge or 8 gauge wire from the alternator back to the battery in the trunk and fuse it with a 50 amp fuse in case of a short. Get the wire and terminals from a local car audio shop.

I actually run a big regular batt cable to a bulkhead on the firewall that goes straight to to the batteries.........The fuse or relay was recommended so I will also do that............ Do I need a bulb/light like stock cos it's been w/out since day one......

Iv had a 1 wire denso a long time now. Just 1 10 gage wire to battery. I beleive when the alt spins it turns on. Easy peezy.

None of the actual charging amps goes through the ignition switch. The ignition switch does send positive voltage to the alt or regulator, Depending on the Alt setup. Stock, the + went to the Regulator from the Ign switch.

Do you have the 4 wire Denso as shown in the above diagram? If so it does need a light or small resister to energize the alt. But, you say your light has never worked. I say move up to a one wire as suggested.

Your big Positive output wire to a bulk head, non factory on the fire wall is fine. But, it does make it tougher to get your motor to lose + volts with the trunk mounted kill switch. Is that operational now, as wired previously? If not, time to address that as well.

But, Whats wrong with your ignition switch. You can turn it back a notch and lose charge voltage. Most switches are {Acc/Off/Run/Start}. So you have {Acc/no,charge/Run/Start}. That doesn't make any sense to me, maybe just a Wore out ign switch that you can rotate back in between {Run/Off}, killing power to the alt or reg. But I think Denso,s have there own built in reg.

Good stuff thankxx, the ign. click back and loose alt voltage was 15+ years ago and hasn't affected the charging any and the alt is around 9 years old iirc. I raced the car a couple weeks ago and it was normal, fire it up yesterday and 15.1-15.2 at the batteries so some things like us, just die w/out notice and I've gotten my $'s worth out of it on a car it was never intended for. I'll see how the 90 amp Denso works out since a buddy will warranty mine out and give me a new not rebuilt piece.........Thankxx guys, always an education.............

http://www.madelectrical.com/

Good stuff and read through that years ago...........

Well after days of thinking and a basic understanding of how an alt. works, I decided to check some grounds and other connections as suggested from you guys and sure enuff the ground post nut was loose. Not a lot but obviously enuff to make the alt. send more current due to the resistance but I still have the issue where the afr gauge still goes crazy till I turn on the headlights so I will check the headlight connection and ground and go from there I guess unless anyone has another idea..........Much thankxxx guys.............

Dom

Check the voltage where you are pulling power for the AF meter.

Madeletric has some good stuff, I don't agree with suggestions of cutting up wiring harnesses to make improvements. Cutting anything really isn't necessary.

Sounds as though you are still having an overcharge issue.

Cable size running from alternator to battery?
How are you sourcing power for cabin/ignition?

I need to do that as you and a few suggested and it's not overcharging anymore and in fact, is charging less now that the main grounds and power posts are tight. The alt. power cable is actually a battery cable so is it possible it's TOO big and maybe only need a #8? I just drove it and w/out lights the idle, cruise and wfo #'s dance, lights on, rock solid so I will isolate the WB system away from other sources and try again...........Thankxxx.............

Nope on too big... too small is always the issue.

If you have a large cable, as in a 4 gauge or larger running from alt to battery, I'd leave it.

Dom what is the voltage before and after the lights are turned on? Have you checked all the grounds on the lights?

are you checking all the wring by doing a "voltage drop test"? I would check between the alternator case and the battery.

Joe

Voltage is now a solid 14.1-14.2 at idle w/headlights on but as I add water pump and the HHR fan, idle voltage drops to battery voltage and didn't rev it up to check since I was alone testing at the batteries. I wired in relays and halogens years ago so even at 12 volts, they are nice n bright. I will run the afr gauge wires away from the common bus bar and try the starter relay or ? and see how that goes and may just step up to the 90 amp and be done with it...........

This is going to get back to where you are pulling power and wire sizing serving it up.

I'm guessing you have a cutoff switch. If you have a wire headed forward to power the cabin, what is sizing? Maybe take a secondary wire and piggyback it forward to see if voltage increases to a higher level when load from accessories increases. If the voltage is higher, you need to upsize or piggyback another wire forward would be my guess.

Yes on the cut off switch and NAPA made me a big dog years ago but not sure on the exact size but it was WAY lighter than the welding cable and I only lose about a .10 of a volt from the alt. to the batteries in the trunk...........The HHR fan and the Moroso water pump are needy for sure in the amp dept...........