A few weeks ago I had my Delco AM radio serviced and tuned. When I brought it home, I thought I'd see how it sounded, so hooked up the battery, turned on the ignition switch, switched on the radio and I had sound and many more stations available than before. Success!
While I had the battery hooked up, I decided to just recheck other electrical components. I'd checked them before and all worked well, but decided it couldn't hurt to do one more check. Turned on the ignition switch and switched on the blower in the HVAC system. On the low setting it struggled to reach desired speed and when moving it to the mid and high positions it shut down. I tried it a few more times, even switching the ignition off and on a few times. Intermittently it would work on low or even medium speed, but wouldn't work on high speed. I got it to go to high speed a couple of times, but it would shut down completely in a few seconds.
I consulted on this with Loren and we agreed that the blower switch was the likely culprit. So I have a new blower switch on order.
Meanwhile, Loren had recommended that I buy one of the NOS ignition switches that were on sale on Ebay last week to provide more confidence that I wouldn't suffer an overheating situation with the old switch in the car. So I bought a couple. This morning, I installed the new ignition switch and it seems to work fine. Now to the "connection"....with the new ignition switch the blower works flawlessly. Works first time at all speeds with the ignition switch in either the "ON" or "ACC" position. I'm still going to install the new blower switch when it arrives to provide more confidence, but this was a surprise.
Just wanted to share this experience as a way of saying that obvious or logical doesn't always apply to electrical problems in 50 year old cars!
FYI and a good weekend to all!
Chuck