Members,

Quick questions on the alternator on my 1993 Base RX7 FD. (I introduced myself a couple of years ago here: https://www.rx7club.com/introduce-yo.../#post12111467. In that introduction I write that I am the original owner of my RX-7, and that it has remained nearly stock.)

I have decided to finally address some deferred maintenance issues, and in fact have a pair of carbon fiber headlight covers on the way right now.

But, my questions: My year-old battery (Duracell) was replaced today under warranty at SAM's. The technician said that it appears that my 28-year-old original alternator has gone bad. (IIRC, it's putting out ~12 volts instead of ~13.5.)

1. Are these OEM alternators known to go bad? (The car has ~167K miles on it; the "new" engine, replaced c. 1995 under warranty at ~48K miles, has ~115K miles on it.)

2. I have an appointment tomorrow at my local Mazda dealership, to have a complete electrical diagnostic run. If their results confirm the alternator issue, do you recommend replacing my alternator with a new OEM alternator? Having my original OEM alternator repaired (if this is even possible)? Some other solution?

3. My long range plans are to eventually "improve" my RX7 a bit. I would like to have its HP increased to 350 WHP or so. (So, in particular, I hope to retain the OEM clutch, transmission, and differential.) Knowing this, does your answer to question #2 change?

TIA,

rx7diver

 

The alternators are generally reliable and last along time. But it’s not likely it was replaced with the short block. Those components usually aren’t so it’s well used and probably doesn’t owe you anything.
A stock alternator is sufficient for your goals. You could go rebuilt but personally I’d just bite the bullet and go new OEM.
As prep for performance modifications I recommend you focus on cooling modifications first. Search the 3rd Gen. tech section and the stickys for more info. Unless you drive like an asshat (and if you’re an adult and put that many miles on the car, I doubt that’s the case) the transmission and diff should be fine. You’ll probably need to improve engine mounts over stock and a mild upgrade on the clutch is probably a good idea, but nothing radical. Along with the clutch I’d replace the clutch fork. They have some history of fatiguing and failure over time and with a stiffer pressure plate.
If your chassis has that many miles and it’s never been addressed, the suspension needs some love. New bushings etc. Personally I’d also do that before performance mods too.
When you’re ready for more power this might interest you. It really doesn’t take much. The key is supporting mods like cooling... https://www.rx7club.com/3rd-generati...added-1104322/

 

I'm not sure I would pay them for this. Checking the alternator is pretty straight forward with a basic multimeter.

You could find a used OEM alternator in decent shape either on the classifieds section here, or on ebay. Going for a new OEM alternator is fine also though.

 

places like autozone and advanced auto will test for free.

 

Bad news: My local Mazda dealership confirmed that my alternator is bad. I was set to have them replace it with a new, OEM alternator, but they couldn't source one. I told them I would try to locate one, myself--if someone here cannot recommend a source.

Thank you for your above replies and suggestions. My immediate plan, after replacing the alternator, is to take care of a few minor things first (e.g., replace headlight covers, replace driver's door seal, fix gas lid release, purchase and install fire extinguisher, etc.).

And then I will have the health of my 13B + TT assessed (e.g., compression test, TT boost/function test, etc.).

At some point I need to have my driver's seat recovered. (My ample behind has left it in really sad shape: The leather seating surface is toast, and new foam/cushions are absolutely necessary, probably!) The driver's side carpet finally wore through last month and now reveals the metal floor, so this will need to be repaired. The AC needs to be fixed. (I was told I need a condenser.)

However, I might begin having my list of important repairs/mods addressed before this last stuff is done. The list is growing ever longer, and being rearranged, as I read through and learn from the extensive RX7CLUB.COM threads.

Thanks,

rx7diver

P.S. I'll post a pic of my engine bay soon (as seems to be what's done here). And when I have a bit of time, I will leaf through my stack of service tickets and summarize significant repair/service work that has been done over the years, and list significant stuff here--for any of you who is interested.

 

Like I mentioned, you can get a used/refurbed replacement for under $100 pretty easily on ebay. Sure there are some forum members with a few used ones laying around as well.

I don't think the OEM part is still available through Mazda (N3A1-18-300R)

IRP also sells a beefed up version of the OEM alternator but it's a little more pricy and probably not necessary for your car.

 

Here are the requisite engine bay pics. Yes, it's quite dirty. I lived in the county, off of a gravel road, for a couple of years. IIRC, the engine has been cleaned only once (maybe twice), ever! Don't judge!

rx7diver

 

Well, this is embarrassing. However, there it is, as plain as the nose on my face: Going through my stack of service tickets, I found one that records that I had my alternator replaced once before, in early 1999, at 118K miles, by my local Mazda dealership (under its previous name). Remanufactured alternator (N3A1-18-300R). Yep, that's my signature. And my CC number!

I wonder what else I've forgotten. Or repressed ...

rx7diver

 

Edit

 

Advise, please:

After my alternator is dealt with, and assuming my 13B + TT check out AOK, and assuming I will deal with cooling first (as several Members suggest above and on other threads), would you recommend:

(a) Add a second oil cooler (a la R1/R2) first?
(b) Add an Al radiator, intercooler, and AST first?

(I need to do some looking and prepare a budget.)

Thanks,

rx7diver

 

I’d focus on the radiator and AST first. The plastic material of the radiator end tanks and the OEM AST have some history of failing catastrophically with age and heat cycles.
Good time to replace hoses, do a coolant change and thermostat too.
A bigger intercooler will only be more efficient at cooling the air going into the engine. It will do nothing for cooling the engine itself. It is a performance modification, not a reliability modification. I would take care of the things I previously mentioned first.
Adding a dual cooler is nice but since you’re not a DIY’er I wouldn’t put it at all high on the list.

 

Thanks for the advice, @Sgtblue. Yes, I lost my original radiator a couple of years ago (just as I was leaving my neighborhood for a Sunday drive). I had it replaced with a new OEM radiator by my local Mazda dealership. I will probably wait a bit before replacing this still relatively new, low-mileage component.

However, I'll likely replace the AST, myself, soon. I don't think I'll be able to screw this up!

I used to wrench on cars, first as a child, with my dad, and then later on, while attending graduate school (a couple of VW's and a Fiat Spider), by economic necessity. My RX7 is my first brand new car, and I have never wrenched on her at all! I might begin to do a few things on her, myself, though, if only simple, everyday tools are involved.

ETA: After I had my radiator replaced ($$), I became a bit paranoid, and now I have my cooling system flushed and checked annually. Just had this done most recently about two weeks ago, in fact.

rx7diver

 

Beautiful Autumn day here. Since my vacation days are maxed out, I took the day off and just now installed the new carbon fiber headlight covers that arrived via UPS yesterday.

The good news: Carbon fiber is surprisingly lightweight--even compared to the OEM plastic covers!

The not so good news:

1. On the left headlight cover, both engagement tabs closest to the windshield are severely misaligned; the associated screws can engage neither of them! (See pics.)
2. The finish on the covers is not what I would call "showroom quality". (The weave is beautiful, though.)
3. The right headlight cover does not seem to fit correctly. I will uninstall it and reinstall it after dinner. Maybe it's something I did (or didn't do). Pics later.

rx7diver

 

I have had several alternators rebuilt locally which is much more cost-effective and better performing than sourcing a reman.

 

Thanks, @s2kevan . To maximize my future options, I likely will go with an IRP reman, as recommended by a couple of Members, above.

rx7diver