I have a mission of mercy to do this weeked that is 2 hours out of town.  My son has an '87 GL that he tells me has a bad alternator which he diagnosed with his VOM accross the battery terminals and the voltage is around 12 v with the engine running.  Connections are good and it's the original or maybe the 2nd alternator.  I see NAPA has this one 

https://www.napaonline.com/en/p/RSE2138521

 

My concern is that I buy the part and it's just a little different so it won't fit or the pulleys arte different etc..... you get the idea.

With all the collected wisdom here I am wanting to know if these alternators are pretty unversaal for this car?  I think his is a Hitachi.

https://www.autozone.com/batteries-starting-and-charging/alternator/subaru/gl

https://www.ebay.com/b/Alternators-Generators/177697?maspect=contextType%3ACAR_AND_TRUCK&Model=GL&Make=Subaru&Engine+-+Liter_Display=1.8L&Engine=1.8L+1781CC+H4+GAS+SOHC+Naturally+Aspirated&Submodel=Base&Year=1987&Trim=Base+Wagon+4-Door&LH_PrefLoc=1&rt=nc&LH_ItemCondition=1000

 

 

Don't know how fast you need it but it's usually better to order online for an exact fit because you can be very specific about the vehicle it's for. That has been my experience anyway.

I've alway repaired my alternators. I have had decent luck with napa parts fitting and quality in general. I always buy their higher grade parts, not the cheap ones.

 

Original alternators usually fail around 150k miles due to one brush wearing out. Like clockwork. I've also had a couple rectifiers fail. When I repair them, I replace the bearings also.

Some people can't or don't want to repair an alternator. The ones for sale are all remanufactured anyway.

I've alway repaired my alternators. I have had decent luck with napa parts fitting and quality in general. I always buy their higher grade parts, not the cheap ones.

 

Original alternators usually fail around 150k miles due to one brush wearing out. Like clockwork. I've also had a couple rectifiers fail. When I repair them, I replace the bearings also.

 

Dave, where do you buy your old Subaru alternator parts from? do they all come from NAPA? i would love to repair/rebuild one myself, but the internal components cost either almost as much or more than the whole alternator itself, this is why its not worth rebuilding one these days, as far as i could tell..

Edited May 2, 20187 yr by Subasaurus

Me, I'd prefer to sat time & effort, let someone else do that, and buy a reman. 

I have always repaired things at the component level.  Repaired electronics from before I touched a car.  Remans were not common back when, and I often had more time than money.  Also, I've read about how much trouble people have had with aftermarket alternators, so I'm not interested in those.

Here is the place I get parts:  https://www.aspwholesale.com/index.php

 

They have pretty much everything, for tons of alternators.

 

One of these days, I have a feeling I'm going to have to figure out how to rebuild a water pump, since sooner or later, they will be NLA.  The only question with those is where to find the seals for the coolant.  The FSM actually has instructions on how to do it.

Now he's telling me it's putting out 14v so his no crank condition may be narrowing to whether he has a bad connetion, the 1.5 year old battery is weak (unlikely) or if its the starter.  I explained how he can do a quick and dirty starter draw test.  If it's the solenoid or worn starter, the I may have to look for one.

If it is click and no crank, it's time for the relay mod. Lots of threads on here about it.

 

14v might be a touch high, if measured with probes on the battery posts - not the clamps.

 

After a full day at rest, no loads, don't open the door, check the resting voltage on the battery. 12.6 is fully charged. 12.0 is fully discharged.

Thanks Dave-

I'll have him check the battery like you suggest.

If we narrow down to solenoid/starter why make the realy modification? Why not just replace the starter?  Car has almost 400,000 miles on it and was wrecked once by my wife in 2001 who t-boned a 4-Runner.  I replaced the front end sheet metal on that one.  Then my son rolled the car 5 years ago avoiding a deer, and we patched it together again.  He just uses it to go back and frthto campus nowadays, so a cheap quick repair is the way we wnat to go.

Actually, there are 2 common causes of click no crank. High resistance in the wiring to the solenoid, which is most easily fixed by the relay mod. And the other is one of the 2 contacts in the solenoid has worn down to the point it no longer closes the circuit to the starter motor. That contact can be replaced. In these cases, the click no crank starts as an intermittent problem that gradually gets worse.

this is what bad contacts look like.

Maybe the solenoid just needs a birthday. 

Can the plunger and contact be purchsed? 

 

Didn't see it ihere.

 

https://www.aspwholesale.com/index.php

Not sure. I've had a number of them apart, the plunger contact is a lot larger than the fixed ones, so the wear it sees is far less. DC tends to arc more metal away from one contact than the other. The looser on these starters is one of the fixed ones. You will have to go through many of the fixed contacts before the plunger one is worn out.

Thought I'd follow up on the fix here.  Very simple- the negative battery terminal was original and as it is 31 years old, it was thin, corroded and not able to clamp tightly to the battery terminal.

A new terminal fixed it. I had to drive to Santa Cruz to "diagnose" this but hey- cheaper than an alternator or starter!