DIY alternator rebuild

Looking at eBay, Google newsgroups, and Haynes Repair Manual on the best buy for fixing a high output 108 Amp optional OEM alternator for an 1984 Buick Century Limited V6-231 3.8l with fuel injection and A/C. The Delco Remy 1-05-45P factory alternator lasted 110K mi over 19 years and had a failure due to a low 10-12v output. The failure showed by discharging the battery but the idiot light was off or barely glowed. A low charging alternator causes a on-the-road problem because the electric fuel pump doesn't work with a dying battery.

Had replaced the OEM fuel pump and 3+ yr old Sears DieHard Gold battery about 2-3 weeks earlier. The old battery had low reserve capacity. When replacing the battery with a new Sears DieHard Silver, upon full overnight recharge, the battery lasts about 2 days with daylight driving, but only about 2-3 hours of driving with the headlights on. When near the end of the battery discharge curve, the electronic dash display digit segments start to glow dimly and erratically. You have about 1-4 minutes to get off the road before the engine quits!

Found that the best used price was $20 + shipping on eBay; but the Seller did not know the model or amp output. I believe that a 78 Amp alternator is OEM standard. Found a 98 Amp recycled one at local junk yard for $45 + $5 core. A 98 Amp remfgrd one at Checker Auto parts was $80 + $5 core; and same at $120 with "lifetime" warranty.

Also found a Victory Lap Alternator Repair Kit, Model GMA-01, for $14 at Mills Fleet Farm Superstore (Wisc hqtrd). The kit contained the regulator, diode trio, 3 sets of brushes and springs of different lengths (0.5, 0.65, 0.75"), and a main ball bearing (unused). The kit also can rebuild alternators for 1968-87 Chevy, Olds, Pontiac, Cadillac, and GMC trucks (AMC + Jeep too). The kit does not include the diode bridge assy (with heat sink fins), capacitor, or wire wound resistor. Decided to do a kit rebuild.

Using the Haynes manual p5-10, it took about an hour to disassemble, replace parts, and reassemble. Needed 6 and 8mm sockets for bolts. The old brushes appeared good but worn too short 0.35-.45". Used the longest brushes set (2 @ 0.75") as could see lots of carbon black stains on the external case of alternator. Added synthetic grease to rear needle bearings. Then took rebuilt alternator to a Checker Auto parts store for their free functional alternator / battery checker. Passed at 14-15 volt output. Reinstalled with new v-fan belt with 13mm sockets. Make sure that the field connector has the locking tab facing the front pulley, matching the notch in the case.

On another alternator, I reversed the stator / field connector with battery connected and it sparked and probably blew the regulator. Noticed that the Victory Lap instructions and Haynes manual did not have a schematic of the charging alternator circuit and color coded wires (XXX is left facing pulley) which could have prevented this accident.

See better explaination in JE Duffy's Modern Auto Technol, p382

Victory Lap, CPI Parts Div, POBox 678, West Concord, MN 55985, (800)

752-4622

Good luck on your own rebuild job.

Regards, Phil, Minneapolis, Minn, SiliconTundra, USA

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Phil Lee
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