Alright. So about a year ago I had a edge evo ht fry my ECM. I have been reluctant to add a tuner again after that but I purchased an edge ez today. Truck had new alt installed 500 miles ago btw. So I installed the new tuner and now I have low voltage and check guages light. Put new batteries in today due to a failed load test. Didn't fix it. The Main alternator fuse isn't blown and the terminals that run to the fuze arnt getting any voltage. Batteries read 12.5 when trucks off. They read 10.5 when running. I'm very concerned this stupid edge is causing problems again. Any I ideas?

 

Have you ran a scanner to check for codes?

 

I hate to say it, but sounds like you feed another ECM to the edge ez. I think I recall a way to jump the field wire just for a few seconds at the alternator just to make sure its able to charge, the rest is up to the voltage regulator which is built in the ECM.