I have been checking with every electrical engineer who will listen about the issue of what to do to protect your electrical system from a catastrophic fire event when installing a higher amp alternator than your ammeter gauge is capable of handling. Ammeter Shunting is what you hear is the answer. Problem being, there is no shunt product that is matched for a 50 amp meter (that is in our trucks) and a larger alternator. The ones that are available are expensive and very LARGE. The reason has to do with metallurgy, resistance values in the micro-ohm range, and its just not feasible to address.
So, one of my more down to earth friends (yes I have a few), told me about his late 60's Chevy car. They put a 40 amp charging system with a 30 amp gauge. To make sure they didn't burn down the vehicle, all that is required is to put in a 30 amp fuse in line with the ammeter. In OUR case, the gauge is 50 amps max. So, the prudent and safe thing to do is put a 50 amp fuse in line with the ammeter. Just a beefy 8 gauge fuseholder with at least a 40 amp fuse in it will make sure you are safe from your truck burning down to the ground!
It's an easy solution to a complex problem that will give you the same peace of mind you had before you went to a larger alternator.
This is the fuseholder that supports the AGU Fuses:
http://www.amazon.com/gp/product/B007WX0NMS?refRID=4V6G9Y71M23XFH5AY3NR&ref_=pd_rhf_ee_p_img_4This is the 50 amp fuses to match your 50 amp gauge:
http://www.amazon.com/gp/product/B001JYPD12?psc=1&redirect=true&ref_=od_aui_detailpages00For those of you who use that extra Alternator amperage for Inverters, etc, there are Shunts available but they are 6 inches long by an inch and a half wide.
http://www.summitracing.com/parts/sww-407616?seid=srese1&gclid=CPv-6OWoosgCFYM_aQodpoYK4A(they do not look that large in the picture) Hope this helps!
