[j_Zer0]

Just wanted to share the resolution to my issue (partial boost was working, but full boost wasn't). Rob thought it was being caused by drained dump batteries (full boost requires more voltage than partial) and suggested I charge them. I hooked up my dump batteries to a charger, but found them already fully-charged. As a last resort I ordered new dump batteries (mine WERE 2 years old -- maybe they weren't dumping all that well any more). If nothing else I could rule-out dump batteries as the cause. But as soon as the new batteries were in, full boost was back. Again, mine started failing right around the 2 year mark, so if you start to notice boost dropping off above 5K RPMs check your dump batteries.

Thanks to Sojhinn, Rob and TM for helping me find my way to the solution.