Before I bought my E28, the guy who owned it turned on the heater blower while on the highway and it just stopped working, he blew a fuse, and some came out from the engine. The blower that was in it was completely wasted--old age I suppose. But, I recently had a problem with my new blower not working. I could only run it on 3m or I would blow a fuse. The reason for this was because the blower was not properly oiled, so it was not able to spin. You might remove the firewall and oil up the blower, as this might be your problem. Hope I helped. Happy New Year.