This weekend's Adventures in #VolvoLove added to my knowledge base:

Someone has in the past rebuilt my headlamp dial switch.

Replacing the components most likely to go flying if it pops open will cost you about $2 at Ace Hardware.

Replacing the switch assembly (not including the relay socket) costs about $55 at the nearest Las Vegas, NV Auto Zone and requires ordering for delivery from a different store.

The components most likely to go flying are two ball bearings and 3 compression springs (springs 4 and 5 under the dial seemed to be a nice tight fit and not under pressure.) They don't carry them that small at Ace, so I bought a larger one of the right diameter and trimmed it to fit #3 spring that just vanished.

The mystery ball bearings go to the underside, each one nestles on the springs and fit into the little daisy-like notches. This provides the "click" as you go from "off" to "driving lights" to "headlamp." The prongs that plug into the relay are long enough that rather than trusting another dose of crazy glue and crimping from the previous rebuild (which is what failed) I have a small cable tie holding it together.

Next challenge: Why the headlamp/key dinger running while the headlamps are on causes Fuse #16 to blow. Lev suggested it was a flaw in the wiring mod he did bypassing the dimmer dial, and the headlamp switch breakage happened while I was putting that part of the dash back together.

I'm not sure any of those are actually related, but those two things together are the only things I can connect to the effect of the zzzflashpop effect on the fuse (watched the fuse actually blow, which is kind of neat.) I'm not even sure what search string to use for tracking it down - any help? I don't mind looking back at old posts on the subject.

Thank you!

...Blanche

 

Dunno about older Volvos but on older Audis (mid 80 vintage) it was common to relay the headlights to not drive all the current through the switch.