Lucid you are correct in that, that the way you say it should be. Yes I know, The Post Owners wrecked the car and put every thing back together sloppy and rigged it to work. Nothing matches up at all and they had a long large belt going around the wrong pulleys.
I really did not want to get into a big discussion on it, as this belt situation has been along time ago and very vague in my mind now. I simply wanted to state that I only use one belt for the alt. Every thing I have done to install the second belt never works, the second belt lines up with no other pulley and the second belt burns up and breaks. Missing stuff under the hood, or wrong pulleys altogether. I am sure.
The belt that the PO used, went from the alt to the upper part of the fan pulley and then down to the A/C then under the crank pulley than back up to the alt. One big circle "CRAZY A'"
I knew it was wrong when I got the car, but it worked until the A/C bracket broke.
Now the pulley for the old alt. did not line up with the fans/crank pulley "ever" even with new bushings and washers. So I am left with a single belt for alt.
The A/C pulleys don’t mach up or align with the rest of the pulleys. After many days dealing with this in the hot Florida sun I gave up years ago and just left the two belts one for the PS, and one for the fan/crank/alt.
It is almost like underdrive pulleys in when I nail it the crank slips alittle bit freeing up some horse power. Yes I know around only one or two HP saved but it all counts, then when to tork levels off the belt stops slipping. It is like Hole shot kinda. This only accures when I nail it to the floor and only for a split second letting the engine build power faster.
The down fall is that I have to cheack the belts more often and replace them every year. Other than that it is not noticed except for a short burning/slipping sound when I launch the car hard or down shift at speed and nailing it at the same time. I drive my car hard. It's a VOLVO!!

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Kevin * HONDA spanking,1985 240DL * VOLVO ON!!!!