Re: Blower kills ignition...sometimes
You probably have a bad ground somewhere. I'd start by tightening any electrical connections that are bolted or screwed down. Start out by disconnecting one battery terminal. Do all the grounds and any alternator connections, also do the connections from the battery to the motor, and all the connections at the starter and the remote solenoid. Make sure to find the blower wiring and clean all the connections for it, including cleaning the switch contacts and it's fuse contacts or circuit breaker contacts. Any contacts that look corroded should be disconnected, wire brushed and hooked back up. The rest can just be hand tightened to be sure they are snug.
Now run it and see if your problem persists. If it does you can clean up the master plug, it's kind of a pain in the derriere but you gotta have electrics.
I did mine by unplugging it, then I took fine grit emery cloth and cut off little bits which I rolled up and used to sand the insides of the smaller plug holes, then I wrapped some emery cloth around the shaft of a snipped off q tip to do the larger holes. I turned some more emery cloth around the other way and used it on the male plug ends. Then I took a sharp pocket knife and used it to spread the male contacts a tiny bit. Last I put a little dielectric grease, just a little bit, in each hole, being careful not to create tracks between the different circuits. I used a cut off q tip to place the grease.
Before I did this I had all kinds of wierd things going on with my gauges. That was 4 years ago, not a problem since.
