I put a 215 amp alt on my truck to keep up the batteries while snow plowing.
I left the original wire to the passenger side battery and added a new wire and 175 amp inline fuse to the driver side battery, where the plow is wired to. Also added a heavy wire to the alt ground lug and ground on motor. I did all the searches and never really got a proper wiring diagram for the small plug. The plug has 3 pins and a jumper which is not used and plugs right in to the new alt. The alt was great, plowing with lights on and heater blower running, the volt gauge did drop some but plow lift never slowed down. Alt only lasted 1 1/2 months . Was a Champion rebuilt that I bought from Canadian Tire, because was only $332 and $10 core when NAPA was $1200 and $280 core. They replaced the alt but before I put it back on I was wondering if anybody has anymore info on whether I wired it properly or if I should do something different.
95 F350 4x4 XLT Lariat PSD E4OD 4:10 LS Camper package purch Mar 95 Command start, super chip(died),BD 3" downpipe & 4" cat back,cat cleaned, switched EBPV,shimmed fpr 76 psi,Homemade open air intake & HX hose,Pillar mount Autometer pyro boost & trans temp. gauges,2-Trucool 4590, B&M trans filter,Sparky AIC plus extra relay for command start,BFG AT 285/75/16. Western Wideout snowplow.Airbags frt + rear
Wifes truck 2004 F350 CC 4x4 Lariat 6.0 L Auto 373ls 285/75/16 BFG AT adj. pedals,AIC camper package,Ford gold starter, Air Raid air filter.
99.5 F350 4x4 Lariat sc PSD Dually, command start, homemade open air filter,zoodad mod,6.0 trans cooler,DTT trans,Mag-Hytec trans pan,Pillar mount Autometer gauges, 4" stainless exhaust(chinese MBRP copy?),Aero 4040XL Muffler, DP Tuner F6, ATS ported turbo housing, Tightened wastegate rod, Boost regulator
Your main cables sound like they are heavy enough. If you were getting the proper voltage then I would say that the small plug was correct for your installation. I believe you said you have a good ground from the engine to the frame. Good. Believe it or not, an improperly grounded alternator can take out your crankshaft. Grounding your alternator directly to the frame is a good idea. Ford had to pay for a bunch of 3208 Cat cranks in the late 70's because of grounding issues.
Interesting story actually. Ford has used a lot of 3208 Cats over the years in their medium duty trucks. In the late '70's a lot of fairly new trucks started losing crankshafts and Cat had to cover the warranty cost. Finally, a town DOT worker who lost one engine already noticed the same oil pressure flutter on another truck and shut it down before it seized. They brought it into Southworth Cat in Albany, NY. Same dealer I deal with. The mechanic who found the problem, Steve, described to me how he did it. He found what looked like arcing scars on the bearings. He dropped the pan, put a curtain around the lower end and a big catch pan. He then fed the oil pump from a 55 gal drum and had somebody start it while he watched. He could see sparks jumping along the length of the crank. Seems Ford had forgot to ground the engines to the frame in a large number of trucks. Cat's engineers figured out that because the engine & trans are sitting on rubber mounts the only way for the alternator to ground was to go from the block to the crank and then back through the driveline to the differential. Ford ended up having to reimburse Cat for the warranty costs and Steve was Cat's hero for the day. Got a nice big bonus. He also quit a short while later when the local Detroit Diesel dealer offered him a better position. That was his success story. He also had a rather humorous "Oops" episode which just goes to show that anybody can screw up. Nothing to do with alternators though.