1987RX7guy

iTrader: (3)

Ok so I put the sucker in tonight and it only took me around 30-45 minutes. I used the ghetto rought and went with butt connectors and I kept the old conector for the FC alt JIC.

Anyways it works AWESOME with the exception of TWO things which I am not sure how to fix.

WHen I start the car up it will only read 12V meaning only the battery is holding everything on. If I rev it to 2.5k rpms it will jump up to 14.7v the other is a humming noise that only stops around 10-15 seconds after shutting down. I think this is like on the new cars where the lights stay on for a little while then shut off.

I think the first prob is just a loose wire like before(happened with my FC alt too but it was my fault)

Any ideas for the second problem? the humming noise? or is that normal?

Santiago

PS- Thanks

AcidShock

iTrader: (49)

Heh, humming noise... sure it is not your antenna retracting? When I first got my car I could never figure out what that was...
If it is "electrical" hum noise I am not too sure. I installed mine a couple of days ago and I love how my headlights shine at their proper intensity now.

silverrotor

iTrader: (1)

It's about time you Installed the FD Alternator. Pretty noticable difference, eh?

I supplied you with the neccesary Harness Plug to make the conversion complete. I think you owe It to yourself to Install It. You say If you rev it to 2.5k rpms it will jump up to 14.7v. What happens at Idle? Did you drive It for a good while to experience a full drive and back to confirm? Make sure the belt Is snug but not overly tight. You don't want to smoke the belts and bearings with the FD Alternator. As for the humming, you got me. No reported cases, myself Included, have heard of any humming noises after the car has shut off.

Keep us posted.

Funny you should mention humming and new cars. My GF's new VW 1.8T does that after shutting the car down. This was however determained later to be the secondary Air Pump decompressing awhile off. This was just found last week.

Makenzie71

I'm curious, what's the point of installing an FD alt?

AcidShock

iTrader: (49)

Higher amperage alternator. For me, buying one from silverrotor was more economical than paying $199 for the OEM one. I figured I would get an alternator that was not "working as hard," put out more amps, and pay less for it too. I noticed an immediate difference: my car revved faster (better spark I guess), my headlights were brighter, my idle was a bit more stable, and my music was louder.

Black13B

iTrader: (1)

Almost double the amperage of a stock S4/S5 alternator. A huge advantage when the stock alternators are IMO underpowered for it's task at hand.

1987RX7guy

iTrader: (3)

Yeah man it went SMOOTH. I just need to narrow down where the problem is at for the voltage reading.



when I turn on the car it is at 12v then I rev it up and it is GOOD 14.7v at idle if I had all the **** on it owuld drop to like 13.5 or so. By everything I mean HIGH BEAMS, heater, rear de-frost, wipers, and sqruirters, and the brake lights on.

silverrotor

iTrader: (1)

Okay. The forum Is being slow again...well, does she bang Santiago or are you jumping the gun buddy?

Makenzie71

that's cool as ****...I always have lots of ****** lights and **** (I really like super-ultra-bright-surface of the sun-immediate area ahead declared a national disaster zone fog lights...). So, does it bolt right on? What are the specs on the FD alt? As I've read in this post the plugs aren't the same, but I could just use a couple of typical blade connectors and plug it right into the stock wiring, right?

1987RX7guy

iTrader: (3)

It works good but I just need to figure out what is LOOSE. Last time with the OE alternator it was a loose wire on the under-hood fuse block to the main FUSE. I need to check that but it is 11.30 here so I need to start packing up for tommorow since i have some testing to do (regular cone intake date. )

I did think the humming is wierd though. But over all I am satisfied.

Santiago

1987RX7guy

iTrader: (3)

Could it be that I used 2 gauge wire from the alternator to the batery? :-/

rexn2o

I bought the FD alternator from silverrotor also(thanks again man) and I have the same problem with the voltage dropping to about 13.5. Everything works great, brighter lights, louder stereo, but the same voltage drop occurs. I know it is not the belt... shitty wiring? Oh, and no humming noise either...

NZConvertible

Going from 70A (S4) or 80A (S5) to 100A (FD) isn't quite double, but it is good.

Makenzie71

will any alt work for any car? Just different plugs and ****? I have a 120A mitsu alt sitting on a shelf with no ford to go under it...

Makenzie71

would it be possible to run two seperate alternators? One could be mounted in the air pump mount....hmmm...prolly not.

My88Se

iTrader: (10)

I think that idea has been tried before, I don't know what the results of it where though.

ON the topic of the install, what is the deal with the belts, as the fd's are serpentine. How did you get around that?

introVert

I think Silverrotor supplies one with the alt, if I am not mistaken. I gotta just give it up and pop for one of these. I am killing batteries left and right. This and an optima red ought to cure all my ills.

silverrotor

iTrader: (1)

The FD Alternator that I sell to the community comes complete with optional single or double Pulley. To further compliment the Kit, I go further to provide the necessary Harness Plug for those whom have 86-88 models as 89-91's have the same Harness Plug as 93 onwards. The belts used thereafter are stock direct replacements.

Therefore, If you go with a Double Pulley, you end up using 2 stock Alternator Belts and one stock Alternator Belt should you go with the Single Pulley.

Good to hear all Is well with AcidShock and rexn2o. I was wondering about you guys.

All applicable Info pertaining to the FD Alternator can be found here https://www.rx7club.com/forum/showth...hreadid=172766 Thanks.

My88Se

iTrader: (10)

I am going to have to invest in one of these soon.

Will you still have them available in in say a month or so?

Turblown

iTrader: (12)

If you have to "rev" it up to get the alt going, then the voltage regulator is not working, probably not wired right.

1987RX7guy

iTrader: (3)

Well like I mentioned already this happened to me before with my FC alternator. But I fixed the problem when I found the cables were loose and when I reved the car it would make them touch more. But I have a NEW 2 gauge wire from the alternator to the POS terminal on the battery and a recently installed 4 gauge POS wire from the battery to the starter. I just need to replace the ground cable but I cleaned the NEG terminal with baking soda dissolved in hot water and replaced the POS terminal with a spare NEW on I had so that one should be fine.


I am 99% sure I wirer it correct since it is only two wires and I followed the write-up.



Another note from going to school tody I kept getting a voltage drop when I took her out of ge ar while braking to a stop at a light. 2 seconds later the volts would rise again. My idle is at 750-900 rpm right now and doesn't bounce or rev like it used to(guess it was the FC alt). Is this normal? During the voltage drop I also experience light dimming and such throughout the car.

Any ideas on that?

Black13B

iTrader: (1)

Eh, I know..

But Tony was saying that most of the ones he tests are putting out closer to 130A.

Wanked_FC

iTrader: (1)

Mine puts out 14.6V at idle, and 14.7 at cruise. Never dropping below 13v with ALL the accessories on. Its an excellant upgrade, however I had a problem where the voltage regulator would not shut off because the disconnect relay isn't in the right spot in the circuit for the s4 to s6 conversion. I had to add a relay to an ignition switched source to kill the voltage regulator to stop it from draining my battery in 24 hours.

West TX RX-7

I bought and installed one of Tony's alternators and it was one of the best investments I've done. My factory alt would put out 12.5 maybe at cruise and under 12 at isle. The one I got from SilverRotor puts out 14.6V at idle and 13.9V at idle with my headlamps and on and I run true sealed beam HID's.

silverrotor

iTrader: (1)

I should. PM when you are ready.

Yes on avg. It's a little lesser In the neighborhood of 124. Nonetheless, It settles down alot more.

Actually, that Is a good Idea but usually applicable to storage of longer periods. This also applies to those who upgrade to s5 Alternators. The s4 Alternator has an Internal Relay Integrated In the Alternator that disconnects the internal Diodes from the Battery when the Engine is shut off. The s5 nor the s6 Alternator does not have this feature and It Is the Charging Harness, as it's called, It Is Integrated into the driver's side harness. I haven't started my FC for as long as 3 weeks and It fires up everytime. Take it fwiw.

Thanks for your Input. I remember you being one of the first to Install one of my FD Alternators. You were running a heavy duty setup and you asked me If the FD Alternators could match your expectations? I replied In confidence that It would do just fine. I guess It's sure holding up top notch and It's suggestable to say that you are more than pleased?


Santiago, Is It safe to assume that you have a reoccuring situation that was exact to that of your FC Alternator? Sounds so to me but I'd like to hear more about your setup and If anything else has manifested. Also, I added an 8awg wire directly from the Battery to the Alternator and It worked out great. However, I did this when I Initially upgraded to a s5 Alternator.