Uncle JohnLane,
Very good idea-r!
The low beam light bulbs are much brighter without the bulb integrity sensor, yet that current goes through the dashboard headlight switch whether one has a bulb integrity sensor or no.
In what and how many ways can we call the "bulb integrity sensor"? Bulb out sensor? Bulb failure sensor?
So, you are saying using the current through the bulb integrity sensor to actuate a relay that powers the low beam filaments, yes? That obfuscates the bulb integrity sensor operation, yes, as the bulb integrity sensor would only see balanced current through that side of the relay. No feedback through the relay.
I'd still rather do away with that sensor and make use of relays that bring full current to the filaments. I have all 86+ big square plastic headlamp assemblies. So, I'd hope, with full current, the plastic crappy U.S. DOT headlamps can take fully power filaments using the proper bulb model at the designated watts (current [amp] draw at volts).
A worthy effort to undertake, eventually. I'll consider it while preserving the dash stalk hi/lo beam actuator.
If you'll note, on the 1985 and prior bulb system, the ho/lo beam relay can carry more current draw. The newer giant square plastic bulb system carries a smaller current limitation through that hi/lo beam relay, yet the same pinout, I think.
I miss my 1979 242 GT with the two single beam big round sealed beam headlamps. These were both stock and bright with the old bulb integrity sensor in the black canister Uncle Art points out as the durable model, yet unable to work with the third brake light system.