Haven't posted in a while but I've been out of the country for the last 14 months. I'm back for a couple of weeks and to my dismay, my supercharger is cutting out intermittently. Today I changed the pump out from the Johnson that I had previously (arguably) upgraded a few years back to a new Bosch pump, but no joy. The problem persists. It is definitely the supercharger cutting out because my boost gauge and power response are normal until power dumps and vacuum/boost flatlines to zero under throttle. It comes back and goes out intermittently while driving. Always works out of the gate but typically starts shutting off within 5 to 15 minutes, then may be off for a similar period, then back on, etc.

In replacing the pump today, I did not replace the coolant but I ran the pump manually on and off for several hours to purge air bubbles. I pinched the lines to do the exchange so I only dripped a few ounces that I recycled and topped off the rest. Coolant looks new, but has not been flushed in a while so I will plan to flush and replace, but I'll be really surprised if that cures the problem. Pump fuse checks OK. Someone in a similar post reported a fuse box issue, but I don't have a good feel for how to evaluate that. The car ('03 SLK32) is driven very little and has about 38K miles on it. Has factory SC pulley, but fully isolated cooling system with supercooler and separate reservoir. Other major mods are listed in my sig.

I am traveling back to Central America in two weeks, so I don't have a lot of time to tinker with it and would REALLY like full enjoyment from my car while I'm here, so any technical/troubleshooting suggestions are greatly appreciated.