Is the alternator the first thing to go at 120K?

I've had a wonderful Miata experience since 1999. I've not had a single mechanical thing go wrong. I did replace the weatherstripping at around

30K and I've had my share of poor mechanics at the multi-car dealerships. You know, the ones that have a special Mazda desk to make you think that the mechanics actually specialize in your car. Well, the alternator (I think) went yesterday. The little red battery light stayed on and the wipers sort of dragged themselves across the windscreen. I keep a spare battery (bought one when I thought the battery was dead and was actually out of gas!) and got the same response. The Miata Garage has easy instructions to swap out the old with a new one, so I'm giving it a go. My question now is - What should I expect next? Thanks in advance for any advice.

Regards,

Chris Tabb, VA

Reply to
Chris Rennix
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It's one of those things, it could go at 80,000, which would be unusual, and it could go at 200,000, which would also be a little unusual. I would expect roughly 120,000 to 150,000 miles from a factory alternator.

I would double-check the rest of the charging system for any possible problems first. The swap shouldn't be that hard, but the part is going to be expensive. It does sound like the alternator, but there are other much less costly possibilities as well.

I would probably go with a factory alternator, though there is a very reputable local company that rebuilds them with actual care for about half the price. I would avoid any chain-store rebuilds, such as Autozone. (bad pre-miata memories).

One bad alternator in 120,000 miles, not a bad track record. I never have had cars go so long without problems as these do. I am going on 7 to 8 years without a single visit to a mechanic shop in one of my miatas, only to the tire stores and alignment shops.

Pat

Reply to
pws

I hate to say this, because it's the kiss of death: but I am at 180K with the original alternator in my '90. When I find myself in the same situation as the original poster, I would look first at changing out the brushes. If they are welded in place, it would make things more difficult, but if they attach in a simpler manner, it would be easy. Since I have never had a reason to take the alternator apart, I don't know this detail.

One of the cars in my past was a '70 TR6, which I bought new. The brushes in that car went at something like 20K miles. Fortunately, there was a Lucas parts place in town at that time (did I say "fortunate"?).

Ken

Chris Rennix wrote:

Reply to
KWS
20k?! Ouch! Oh, those were the days, huh? They were fun when they ran though, ya gotta give um that!

Chris

99BBB
Reply to
Chris D'Agnolo

CAS "O" ring. (& heater hose, due to oil on it) Convoluted rubber seal thingy that the gearstick goes through. (under the decorative leather one)

Reply to
Mal Osborne

I just looked in the Enthusiast's Shop Manual and it appears to indicate that the brushes are *not* welded in place. However, it also appears that you have to remove the rotor to replace the brushes and (according to the ESM) it's a real PITA to get the rotor back in.

Iva & Belle.) '90B Classic Red.) #3 winkin' Miata

Reply to
Iva

The problem with installing the rotor, usually, is that you don't have a third or fourth hand to hold the brush springs back while putting everything together. What you can do, depending on the physical circumstances (that is to say...in some cases this works...some not)is to push the brushes back and hold them somehow in that position and then install the rotor. I did this with one of the window motors in the Miata after I repaired a cable that failed. The material of choice, if I remember correctly, was metal tape, cut into a couple of small strips and removed once everything was together.

Sometimes you can be clever. Not always.

Ken

Iva wrote:

Reply to
KWS

I bought a new alternator online through eBay, got it within a week, and installed it today. It took about 2 hours once I had the right tools. I could not find any instructions for replacing the alternator online and tried to use the instructions for the 1992 model. They did not work at all. Once I figured out all of the special things Mazda put in my way to keep from doing it myself, the job was quite simple. The only problem was space and awkward hand positions. While I was at it, I also replaced the main fan belt along with the alternator belt. If anyone is interested, I could put together a "how to" guide. I figure I saved at least $250 doing it myself. All you need is a ratchet wrench with 10,

12, 13, and 14 mm barrels, both a short and long extender for the ratchet wrench, and some black tape.

Regards,

Chris Tabb, VA

Reply to
Chris Rennix

You could submit it to miata.net, it could be very useful to have in their garage section.

Pat

Reply to
pws

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