fastjohnny
Member
Background info: My 99 suburban has become my favorite plow vehicle over my 02 Duramax, for a couple reasons including shorter wheelbase and the 4L80 is much quicker in reverse than the Ally. What I have not been fond of was the dismal stock 105A CS130D alternator, which could not keep up with continuous plow duty.
I had picked up an AD244 like found on my Duramax, and was about ready to swap it in when I got the hankering to just go with dual alternators. Research indicated it was a factory option, part numbers where located, but alas, the alternator bracket is no longer to be found via any GM sources.
Not ready to give up this idea, I did some further digging and found a couple decent pictures of said bracket, which I printed and resized until I had a reasonable full scale pattern, matching my alternator bolt spacing. I traced this pattern on a scrap piece of .027 aluminum coil stock for a more durable template. I used a 3/16" steel plate for the bracket which I cut using plasma, dressed with grinder as needed, and drilled all mounting holes, and welded a nut for the new belt idler pulley. A little bit of work with a die grinder was needed due to some variance in my pattern, but all things considered, it fit very well, and the new alternator bolted up fine.
I had a little hickup on the belt length: the 120"+/- belt spec for dual alternators were for 2 of the small frame alternators, not one large (the added AD 244) and one small. A bit of dumb luck here, the vac pump is not needed, as I have a TM, but had never removed the vac pump. Removing this allowed the belt to fit.
Results: Nothing short of awesome. I can run all accessories, lights including HID's which now don't flicker when I use the plow. Where the volt gauge would dip down and slowly return to <14volts, now it will dip with plow motor running, but pop right up to 14v as soon as the plow motor stops. Also because the alternators are keeping the batteries fully charged, cold startups are no problem, 6degrees today, fired right over, with one glow cycle and no block heater use.
One oddity: For alternator excite, I had a single brown wire on a 4 terminal plug that fit my alternator from an old alternator. I tapped this into the brown wire on the existing alternator, which uses the same plug but has an additional wire which powers the tach to my understanding. My tach will read fine at idle, on start up, and when driving, but after awhile, the tach will get funky, when I let off the gas, it will drop to 0rpm. When I'm on the gas, it reads normal. Any thoughts on this?
Now because of my impatience, I have a spare idler pulley and belt, as I had ordered from GM, but got antsy to get it done, and picked up an idler from NAPA and a belt from Autozone. If I get energetic and/or someone really wants dual alts, I might be convinced to make another bracket, and sell with pulley and belt for a kit.
Pics forthcoming.
I had picked up an AD244 like found on my Duramax, and was about ready to swap it in when I got the hankering to just go with dual alternators. Research indicated it was a factory option, part numbers where located, but alas, the alternator bracket is no longer to be found via any GM sources.
Not ready to give up this idea, I did some further digging and found a couple decent pictures of said bracket, which I printed and resized until I had a reasonable full scale pattern, matching my alternator bolt spacing. I traced this pattern on a scrap piece of .027 aluminum coil stock for a more durable template. I used a 3/16" steel plate for the bracket which I cut using plasma, dressed with grinder as needed, and drilled all mounting holes, and welded a nut for the new belt idler pulley. A little bit of work with a die grinder was needed due to some variance in my pattern, but all things considered, it fit very well, and the new alternator bolted up fine.
I had a little hickup on the belt length: the 120"+/- belt spec for dual alternators were for 2 of the small frame alternators, not one large (the added AD 244) and one small. A bit of dumb luck here, the vac pump is not needed, as I have a TM, but had never removed the vac pump. Removing this allowed the belt to fit.
Results: Nothing short of awesome. I can run all accessories, lights including HID's which now don't flicker when I use the plow. Where the volt gauge would dip down and slowly return to <14volts, now it will dip with plow motor running, but pop right up to 14v as soon as the plow motor stops. Also because the alternators are keeping the batteries fully charged, cold startups are no problem, 6degrees today, fired right over, with one glow cycle and no block heater use.
One oddity: For alternator excite, I had a single brown wire on a 4 terminal plug that fit my alternator from an old alternator. I tapped this into the brown wire on the existing alternator, which uses the same plug but has an additional wire which powers the tach to my understanding. My tach will read fine at idle, on start up, and when driving, but after awhile, the tach will get funky, when I let off the gas, it will drop to 0rpm. When I'm on the gas, it reads normal. Any thoughts on this?
Now because of my impatience, I have a spare idler pulley and belt, as I had ordered from GM, but got antsy to get it done, and picked up an idler from NAPA and a belt from Autozone. If I get energetic and/or someone really wants dual alts, I might be convinced to make another bracket, and sell with pulley and belt for a kit.
Pics forthcoming.