At home alternator rebuild?

[Matthew Jeschke]

We had an alternator rebuilt at a local supposedly reputable shop. They only replaced the worn out parts, not the 1/2 worn out parts, so the alternator broke down a year later. And it wasn't cheap either, it was over a hundred bucks Cdn.

there is a rebuild shop here where i live too. I wonder about same thing. The parts apear cheap to rebuild them, just want to make sure I order the right parts.

Sent from my SM-A505U using Tapatalk

 

[Larryjb]

With a kit, you get what you get, kind of like buying a computer vs. building one. When buying pre-built you have limited control over what components were used. When assembling with your chosen parts, you get exactly that and you know what you're putting into it.

For me, because I'm not familiar with what parts should be replaced, and what parts are junk and should never be used, the kit from Rebuilderinabox has been useful. They may not be top quality parts, but both alternators that I rebuilt lasted the remaining life of the cars I put them in which was a few years at least. The starter that I rebuilt from their kit has been in for 2 years now, no problems yet. (In fact, the ACDelco "new" starter that I installed broke within a day. It took me only an extra half hour to rebuild the existing starter motor from his kit.)

 

[Doubeleive]

a lot of places stopped rebuilding alternators because the newer ones (2-pin) are digital and the machine used to test them cost's like $10-15k so unless it's a large company that can drop the money on a new machine they just don't rebuild them anymore the shop here in my town used to have like 6-8 guys working busy as hell, now they have 1 guy and they just rebuild the older ones and the ones used for farming equipment and the price is almost the same as just buying another one already refurbished.

 

[new2yukon]

a lot of places stopped rebuilding alternators because the newer ones (2-pin) are digital and the machine used to test them cost's like $10-15k so unless it's a large company that can drop the money on a new machine they just don't rebuild them anymore the shop here in my town used to have like 6-8 guys working busy as hell, now they have 1 guy and they just rebuild the older ones and the ones used for farming equipment and the price is almost the same as just buying another one already refurbished.

Squeezing out the small guys.....not good for little guys like us.

 

[Matthew Jeschke]

This two pin connector (pic below)

As to building what you want, I'm assuming a new coil would need swapped into get higher output?

I see this rebuilder in a box is pretty sweet. He sells the basic stuff though the voltage regulator, bushings, and bearings. No rectifier? I suppose maybe I need to crack it open and gain a little experience, before I ask too many novice questions haha

I seem to see a drop in voltage on my dash when I'm at a hot idle. Not sure what exactly that indicates.

https://alternatorstarterrebuildkits.com/product/ad244/

I never noticed the part number and amperage rating on the alternator until I took that picture and the flash hit it haha

 

[Matthew Jeschke]

I ended up buying a 250 amp alternator. I have run it since July of last year. Was nothing short of a small fortune to buy. Having some little electrical gremlins so I pulled out my power probe and started checking grounds. Then checked the alternator.

The alternator at idle w/o any accessories on, but engine running of course, is showing 50 to 60 millivolts ripple voltage. I thought that's a bit high. I see they did a test before selling me the alternator and said ripple current was 11 mAmps. I don't know my load though so that test isn't very helpful. Every mechanic I know of tests ripple current (ac voltage) from bat positive to alternator positive. They told me to measure current and call back WTF am I going mad? I don't have a amp meter for that. Wouldn't the ripple voltage test indicate something to them... assuming the load is somewhat reasonable?

I'm wondering if I need to pull the alternator and go back to them with it. Kind of stupid. Wouldn't a shop have some idea of what's an acceptable ripple voltage?

 

[mattbta]

Which brand? I got the Mechman 240a. After running through misc tests they had me do because I also have drop, sent it back in and they replaced the voltage regulator. Still have voltage drop at hot idle with HVAC blower medium-high speed and electric engine fans going. 2004, so no RVC. Did a big 5. Doesn't seem to matter if i run the 500w fans or the 700w - still drops when AC cycles.

Will be watching as I now have an ammeter to go along with dvm. Not real happy with the "upgraded" alt.

 

[Matthew Jeschke]

Yeah same here. I'm getting some electrical issues... I am not sure if this is related to my O2 sensors acting very weird sometimes. They read the wrong AFR (I have a wideband) and start running me at around 13:1 instead of the 14.7 I tuned it for until I connect my PCM (Diagnostic port) to my cigarette lighter ground). I recently also got a DTC for O2 heater circuit as well which I've never seen before.

But I digress, it's a Tucson Alternator. The alternator is 250A rating which is kind of silly, that's at like 5000 RPM... but I suppose they all work the same way w/ ratings. I was told it would be a 250A but picked it up and said 240A on some of the paperwork and 250 on others. Their part numbers made no sense.

Originally Tucson Alternator was a rebuild shop in Tucson. I went to have my factory one rebuilt but they said the only build and sell upgraded ones now. They gave me a brand new one they built from a Denso core. The regulator is supposed to be a better one that gives me more current across the board and less ripple (as the guy told me). I also upgraded my charging and ground cables to 1 gauge welding cable the sold me.

Not happy with the cable kit they sold me cause nothing fit. I had to modify it and would have been just as easy to buy welding cable and build my own at that point for fraction the cost.

All aside, they were very friendly and helpful until I called asking about measured AC voltage / ripple. It was like I was taking Chinese to the guy or something. Kind of blew my mind. I can see where current ripple is more useful but in real world that's not exactly easy to measure so most of us measure voltage ripple and the guides I have specs in voltage ripple for which the alternator isn't meeting spec but they spec in amp ripple ug.

 

[exp500]

I've used these parts for 10's of years with good results. Nothing recently though. -

USA Built High Output Alternator, Upgrades, Parts, Kits

High Output Alternators built right in the USA. We also have parts, upgrades, kits, marine and industrial units, guides, instructions, and more.

alternatorparts.com

 

[Matthew Jeschke]

Welp, another confirmation of me being an *idiot* I had my folks run in and get the alternator checked. However, when I took it off, I noticed it had black dust on the case. I should have known...

Tech told them belt wasn't tensioned correctly. He recommended getting a 1/2" shorter belt. However, I went through my maintenance log book. I'm running the original belt tensioner 265,000 miles! Maybe why engine wants to stall when I let off gas *separate* issue. I keep adding timing and it helped but didn't fix that. Belt has been squeaking for years. I actually broke several fingers over that mess... different story, another post.

Still unsure about ripple voltage but they told them it was within their build spec. Little surprised to see 50+ mvolt ripple. Was worried there might be an issue with the voltage regulator.