Installed a Powermaster 140A Alternator

Rexxenexx

Member
Installed a PLX combo today (in another thread) then pulled the Ty in the garage and installed a new alternator. I know what the two tan inline fused wires are for, but I forget what the pinky thick black wire goes to. Fuse block? Curious why they used black instead of red. (Edit: I’m pretty sure it’s the cable they used to go to where the battery positive used to be. Battery was relocated to back.) Anyways, it came out looking nice. It is a standard 140A GM Powermaster 47861 alternator. It did need to be reclocked, you just gotta be careful not to over tighten the bolts. They don‘t need to be too tight because it could actually seize the bearing from the pressure.
Feels good finally getting this shit in the box.

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Rexxenexx

Member
Comparing, before and after, two DM files with all accessories on. This should have been my first upgrade years ago when I had an electric fan. Both Tys I owned wanted to fall asleep at night idle at stoplights. Hopefully that never happens again.

Pre140AltAllAccON.pngPost140AltAllAccON.png
 

Rexxenexx

Member
Aaaaand it died. Check Engine flickered yesterday when I turned on the headlights. I thought because I swapped the footwell LEDs to new ones, maybe they were messing with the electrical when I turned headlights on. Today I put multimeter to batt = 12.01v. It was discharged. Turned the car on = 11.07v. Checked + on alt. while running. 11.07v. Good times. Just the experience I remembered 25 years ago. 😆

edit: the alternator died not the car, just for clarity sake. i just drove it to recycle used oil and coolant before doing the multimeter tests.
 
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Rexxenexx

Member
Bought and swapped in a Duralast Gold POS. Back to normal. 13.31v on the batt. 14.1v on the alt.

Yeah, the alternator was new. I can’t fault Powermaster though. It was working great. There are too many variables like battery relocated to back, under the hood is super hot these days, maybe I F’d it up doing the reclock somehow. I measured each bolt length/surface to surface with a caliper, took it to get tested after the reclock, it was good and it was still straight n true (pulleywise) installed. I was impressed at how quiet it was compared to the stocks *SsSsSsSs*. Such good quality so I dunno.

My GUESS is heat. I haven’t got around to changing out the coolant, but temps on DM seems the same as everyone else with a stock thermostat and it hangs around the first mark on the dash like normal. Just when you open the hood after a long drive the freakn’ heatwave that comes out is like walking out of a Casino in Vegas during the Summer. Gotta close my eyes and quickly put the branding-iron prop rod up. Overflow looks good too.

Gonna look over the DM files, if it’s better than stock I’ll leave the trash tier garbage ugly toilet worthy Duralast in and figure out if they can repair the Powermaster/hopefully figure out what went wrong.
 

Rexxenexx

Member
Well the Duralast is a tiny bit better than stock. Headlights on at a stoplight, I can see every light dim. Especially if I signal left/right.
The Powermaster is shipped out. Hopefully they find exactly what failed and why. Felt like a new car at night with that alternator.
For now, on to the next garage mechanic car problem! 👉
 

Jay92Ty

Donating Member
Ive been wanting to swap one myself. Been reading this and wonder if the stock wiring is not suitable for the extra amps ( wire gets hot) and maybe that caused it to fail? Possibly like you mentioned the relocation of battery ( which I also was thinking of doing) could of caused something? Either way..I'm gonna give it a try. I have a small sound system and a secondary intercooler with dual fans. I ned a lil more power from my alt. Fingers crossed ;)
 

Rexxenexx

Member
If you have the battery in stock location you should run at least 4 gauge (which is what I have now). I really should be running 2 gauge with the battery in the back. The black/gray Ty had the exact same issue when sitting at a light and that thing had the battery in the stock location. Dunno, but I’ll update to 2 gauge soon just to be totally safe.
 

Rexxenexx

Member
They said some part in the back broke, stator something, he didn't know if it was from my clocking, high RPM, or just part failure. They covered parts, I covered shipping. It's bench tested, proper clock, so should be as good as new when I get it. I can't wait to get this alt I have in now OUT. I wish I told him "PLEASE make black powdercoated ones properly clocked! We need them."
 

Jay92Ty

Donating Member
Cool(y) I ended up putting one with a 4g cable and battery in stock location. I didn't clock mine, but overall worked out perfect on the install.
Hopefully I won't have to send mine back;).660C5253-699A-42C8-880B-3A8956675092.jpeg
 

Rexxenexx

Member
Got it back today. It has somethin’ extra. A ground lug. Last week I hid the ground wire (0/0) in the fender. Added a wire to the driver side ground next to the water neck with a smaller wire going to the back of the alternator bolt. I’ll reverse that, big wire to lug, smaller to ground next to water neck when I reinstall it.
 

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Rexxenexx

Member
Reinstalled. I only had to make a new short wire to go from ground lug to water neck/driver head ground. Easy. The main ground had enough slack to reach perfectly.
If I don’t post anything later today, assume it performs like it did before the stator took a dump. I’m just gonna test it later today with Datamaster recording and everything on. I don’t expect any issues. Until 2032, take care! 👋

Update: 13.6-14.0v heat soaked, everything on, in a drivethru idling at night. Perfect (y)

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