130 Amp Alternator

[Geoff]

I had to replace the alternator in my wife's '99 9-3 over the weekend (what a crappy job). I got a rebuilt one and picked up a 90A because that should have been standard for the car. It turns out it had been replaced with a 130A alternator which is standard mid '00 on for 9-3s and 9-5s and optional on the earlier cars.

I took some measurements and its similarly sized to the 115A early '90s 9000 alternator I have on one of my 99s (which is larger than a stock alternator but fits). I remember hearing that the 115A 9000 alternator was essentially an overworked 90A alternator and prone to early failure. The 130A alternator was in the 9-3 when we got it 156k miles ago so it must be decent. It might work good on a 99 or 900 rally car to run a lot of light, or for some dweeb with a big stereo system.

SAAB Part number 49 41 761, supersedes to 85 49 552.
Bosch Part number 0 123 510 096

[SwedeSport]

I think I know one of those dweebs with plans to put a big system in. I know one for sure who's RPM drops by 200 when he turns on his headlights.

I had often wondered if that would work. I'll look for one at the U-pull-it.

[hutch]

Geoff does the alternator mount in roughly the same way as the 90A one? Im pretty sure I remember a guy talking about running a serpentine belt system from a later engine, that would make mounting one a little easier if it bolts up.

The 130A in my '01 9-3 is definitely much nicer than the lousy ones in a 900. Even with all the extra 'stuff' the more modern car has it rarely dips the lights unless you're close to stalling out.

[Geoff]

Yeah, the mounting bolt pattern between the alternators (C900, 9000, NG900/9-3, 9-5) all seems to be the same: 15cm between the mounting ears. They all seem to be the same angle between mount ears. 99s have one deep mount ear (long bolt at the bracket) and one shallow mount ear (short bolt at the tensioner) but you can just use a long bolt at the tensioner instead if you want to use a later alternator.

I didn't check the length of the mounting ears but I've compensated for that before with material removal (grinding) or addition (washers).

I suspect the pulleys are interchangeable between all Bosch alternators.

Fitting a larger alternator in a C900 is always a challenge, but I've known people who've put the 115A earlier 9000 alternator in so the 9-3/9-5 alternator should fit.

Below are some pictures of the 90A alternator I put in (clean) and the 130A that came out (dirty). You can see the size difference. I think the 90A is probably about the same size as a C900 90A, which is similar sized or maybe a little larger than a 99 65 or 70A.

The 130A is significantly heavier; there's a lot more winding inside.

[SwedeSport]

Scored a 9-3 130 amp unit at the ez pull. Toyed with mounting it to a c900 engine. In order to use stock mounting hardware a sleeve will need to be pressed to compensate for the smaller mount bolts. The belts just don't line up properly. Either the whole unit needs to move forward 1/4 inch or so, or a new pulley with a different offset needs to be sourced / made.

Yes the pulley just swaps from the c900 alt. but youll need to use the nut and washers from the 9-3 alt.

[Geoff]

Now that you mention it, I seem to remember putting a sleeve in an alternator before to fit it to a 99. I think it was an early '90s 115A 9000 alternator (?). I also remember grinding one end of the mount down and putting washers at the other end so that it would line up. I don't remember which alternator mount I was using at the time though, one was custom.

Overall it wasn't much work to get it in.

[SwedeSport]

I'll tinker with it and get it to work. Im going to look for other alt pulleys to see if I can just swap it for one with a different offset.

A custom pivot bracket could work too. but I would have to make a new support arm as well, and still sleeve it.

[offroadrabbit]

On the topic of alternators, would it be possible to run a second one in parallel? The AC never worked in my 900, so i finally just removed it. I don't know about mounting hardware to fit it onto the AC bracket, or if I could solve the issue of different sized belts between the 2, but in theory would that work?

[Crazyswede]

You could run two alternators...but why?

[offroadrabbit]

Rally lights, hi-beam and a few other things running for night stages. It starts to push the OEM alternator a bit much for my liking. If I was drawing 70 amps, 2 alternators wired in parallel would produce 35 amps each... but would I need to beef up some of the wires to handle potential loads above 80 total?

The primary reason for 2 over one bigger one is that I have a spare on hand from my parts car, so I'd rather not buy a bigger one if I can use what I have.

[SwedeSport]

Redundancy on a rally car is probably not a horrible idea...

If one shits the bed, you at least have a backup.

[offroadrabbit]

Well there's that too, but wouldn't the chance of one failing go down as well because I'm only ever using them to say 60-70% capacity?As opposed to one 130 amp working at 70-80%.
Now that i know I won't blow my car up, I just have to solve the mounting and belt issues...

[RadioFlyer]

So is there any chance of electrical problems with a higher amp alternator? Or is the issue only fitment? I've been thinking about an upgrade for the '80 900t for a while now - definitely has trouble when the lights and blower are on simultaneously and the voltmeter shows it drop below 12 when loaded.

[DrewP]

There's no problem because it should self regulate to maintain voltage. It just means that it can supply up to ~130 amps before the voltage starts to drop with increased electrical load, compared to a 90, which will start to drop voltage down once it's trying to supply more than 90 amps.

Think of it like extra head room.

If the alternator is in good shape (maybe throw in a new voltage regulator, and see what the brushes and commutator shaft bushing looks like. Then make sure your engine-to-chassis ground strap is clean and tight and not corroded.

[RadioFlyer]

Thinking about a higher-amp alternator again in the '80 since everything seems super dim when the headlights lights or radio are turned on. Anyone have experience with an adjustable voltage regulator? Any major risks? Would it be better to just get a different alternator?

Saw this come up on the facebook page: http://www.davebarton.com/AdjustableVoltage.html