Talked to a few experts today on Ammeters and Shunts. The way they explained it to me was the Ammeter Shunt is a protection circuit that allows for excess current to bypass the meter so that it doesn't burn out the meter. (knew that already).
Since the ohm values are so incredibly low, the Stewart Warner engineers decided to make a shunt that is acceptable for UP TO 100 amps, and another one UP TO 150 amps. (this I did not know). The Engineer went on to say that it would be impossible to match a specific gauge to a specific alternators output because this protection device has such generic qualities. We are talking about metallurgy and combining metals to obtain very very low ohm values. This makes matching impractical, as well as unnecessary.
To make sure you do not burn up your truck with a 100 amp Alternator or less, get this one:
http://www.summitracing.com/parts/sww-407616For a 150 amp Alternator or less, get this one:
http://www.summitracing.com/parts/sww-413717I would say if you have a 60 amp alternator or something less than 80, do what Hot Rod Lincoln suggested a long time ago. (sorry Jerry but I am a little slow).
Get a radiator clamp and shape it to look like the ohms symbol, drill a hole on each end and drop this across the two screws on the Ammeter. Be sure to observe any grounding issues and ensure its not touching anything.
Not so fast! I should know better than to look at a picture at the Summit Site and imagine that shunt being almost the same size as what could go across the terminals of our gauges. When I get it, it is 8 inches long and 2 inches wide and is very heavy. It could double as a giant fuse to power an entire building! (or neighborhood)
It does not change the fact that a larger alternator has the potential of burning your truck to the ground should that meters limit get exceeded. So, more research, more testing, etc. is on the list! Please take this issue seriously. At this point it may require changing out the meter internals for a larger rated gauge.
http://devestechnet.com/Home/Native12VUpgrade
