[TR] Fan belt tension - Have reviewed previous postings

[thenicholls at verizon.net]

To the list,

I am preparing to swap my alternator out with a new rebuilt Lucas 15 ACR 
unit on my 1972 Triumph TR6.

I had to replace the water pump recently, which required me to adjust 
the fan belt tension on reinstall.  I do notice that the pulleys do not 
seem to line up as well as they did before, and I see that this has been 
discussed on the list.  Both the water pump and rebuilt alternator were 
purchased from TRF.

The book states 3/4-1", which is where I am now.  My red light is 
definitely less happy than it was before the water pump, had it tested 
and it is putting out 14 volts and 30 amps.  I am replacing this unit 
because it does appear it has some issues, and I will have it rebuilt. 
I also installed an Optima battery during this time.

My question, Star Auto Electric in California says to adjust the fan 
belt as follows:

You should tighten the fan belt just enough so the belt does not slip on 
the generator pulley. To test for possible pulley slippage with the 
vehicle's motor stopped, take your hand and with one of your fingers 
apply rotating pressure on one of the generator's fan blades and try to 
see if you are able to move the fan and pulley. If this action is 
possible and you can turn the fan and pulley without the belt moving you 
need to retighten the belt a little more. I know this sounds tedious and 
time consuming, however if you want to save the rear bushing from 
premature failure I cannot stress enough the importance of correct fan 
belt tension for these types of generators.

Currently with 3/4-1" play, I can indeed move the fan with one finger. 
I am toying with the idea of tightening the belt before I swap to see 
what impact it has on the red light.  It used to just be dim at idle 
(normal), but now sometimes it is glowing red.

Anyone have an opinion on the proper tension without be so tight that 
damage to the water pump and my new alternator occur?

Thanks,

Craig H. Nicholls
Vienna, VA
1972 Triumph TR6