Alternator Woes

Recently the alternator has started playing up on my car.
So I bought a new S14 alternator thinking it would fit.
Turns out they are different.

Main differences between S13 SR20 and S14 SR20 alternator:

• +ive post on the s13 is smaller (M6 thread as opposed to an M8 thread on the S14)
• Upper mounting point on S13 is not threaded.
• Different sized pulleys.
• Wiring connector located on the opposite side of the alternator!

Conclusion:
You could make it fit with some alterations to the wiring and drilling out the upper mounting point but I rather get the right part. From my findings, it seems that the S14 and S15 alternators are the same however, so those are perfectly interchangable.

I then went and bought another one from a supplier that the local auto-electrician hooked me up with. The listing is for 180sx but it was wrong again, I'm not sure what this alternator was really for but it definitely is not for a RWD redtop SR20, I believe it was for a FWD Pulsar SSS SR20, the upper mounting point is different.

After this, I had researched that the alternator from the overseas model KA24 (240sx) would fit with a simple pulley swap and drilling out the threads of the top mounting points.
Ok - so a few weeks went by and my alternator finally arrived from the US.

Main differences between S13 SR20 and S13 KA24 alternator:

• Upper mounting point on S13 is not threaded.
• Different pulleys: KA24 is 4rib, S13 SR20 is 5rib.

So we are two up from the S14 SR20 alternator.

I then swap the pulleys over and find that the pulley sits 2mm out of alignment. The only way to correct this is to machine the back of the pulley down 2mm but risk the back of the pulley hitting the alternator housing.

I also find that when mounted, the KA24 alternator is larger and hits the intake manifold support bracket of the SR20, causing the belt adjustment's minimum/shortest setting to sit WAY before the adjuster itself bottoms out. Which means you'll need to run a longer belt or modify the support bracket to allow extra movement.

I didn't want to fuck around with machining pulleys and modifying the intake manifold support bracket so I just ordered a 2nd hand S13 SR20 alternator from the local wreckers.

So what I'm trying to say is that anyone who tells you (which is pretty much everyone on the US silvia forums) that the KA24 works with simple pulley change and boring out the top mount is rather wrong. The pulley definitely requires machining or you will running your alternator/water pump belt at a poor angle, something I definitely do not want.

Why didn't I get my alternator reco'd? Well the auto electrician wasn't able to source a lot of the rebuild parts for me (reg, diodes, etc).. apparently they don't make them any more for these types of alternators. Now that I think about it I'm actually quite sceptical about this and I really should have gotten a 2nd opinion.

What a fuck around.

Peace.