I ran a Powermaster #7508 on my 340 for three years and then it stopped charging at idle rpms. This car was only used on occasion (dry weather, weekends, etc.). I expected the alternator to last much longer under these conditions. But, it was a Chrysler square back core and they "juiced" it up to make 60a at idle and 99a total. My guess is that these "juiced" up cores will only last so long because they were not made to put out 2-3 times more at idle than what they were from the factory. I assume that the heat that it generated may have been a cause of this short life. Note: This #7508 is no longer produced by PM. They do sell a higher rated version now and I would not recommend it for a long term unit due to my experience.
So, I started investigating new alternators and after contacting three of the major brands, I found that no other brand could make a square back unit (3 wire) that put out the amperage that the PM is getting from their units at idle (that did not cost $325). So I decided to look at the one wire units that would give me 75a-90a or so at idle for future upgrades. After a lot of reading, I found that PM is now producing a "new series" of Chrysler twin fan one wire upgrade units. I talked to their Sales/Engineering staff and found out that this unit is based on the AC Delco #230 core that has twin internal fans and is built to meet Military standards. It has a "stock" rating of 120a and a Turn On Speed of 500rpms. Their new Chrysler Upgrade 165a & 215a units that come with with single or dual pulleys. You can find these on pages 100 and 101 in their new catalog.
I purchased and installed the 165a unit (#8-48529-120: to replace the 60a at idle unit). The 60a at idle unit always showed voltage fluctuations at idle when I came to a stop, but it was much better than the stock unit that it replaced. When I had headlights on or when I was using the turn signals, the flucturations at idle were even worse and my voltage reading would bounce around. So I decided that if I ever had to upgrade the 60a at idle unit, I wanted to try a unit that had at least another 25% more at idle.
Do I need the total idle output of the 165a unit? NO! But, I liked the design of the AC Delco 230 core that they use. This unit puts out 104a at idle (148a at cruise, and 172a at top end) and this means no more voltage fluctuations at idle at a stop. Now I can upgrade in the future and not worry about any power issues.
Topic: New Alternator recommendations (with Vintage Air) (Read 5729 times)
