Drakeule

All: Thanks for the info. This is the only solution that makes any sense! I will attach the schematic ASAP. The schematic seems to (on second look) show a grounding switch like you guys state. However, it appears that it fuses (because of a rear cigar lighter, which my sport coupe doesn't have) and then goes to the "+" side of the Ammeter. Certainly not a ground !

In looking at the schematic for the dome light, it can be activated by the pillar switch or either door jamb switch. Upon examining those jamb switches, it appears to me that the only thing they do is interrupt the grounding when the door is closed. However, the schematic clearly shows that they function as a hot (6V) interrupter (which is what I would expect.) Interrupting a ground doesn't seem to make any sense, as the dome light is already grounded...In fact ,the jamb switches shouldn't even work! I thought that the jamb switch would have 2 contacts, and that one would be hot; when you open the door, it connects the circuit, thus giving the dome light voltage. The way I see it now, if you connect a positive to the door jamb and open the door, you create a short condition-like hooking pos. and neg. on a battery together! Can someone make sense of this for me?

Roadmaster71: Thanks for the response. I have a copy of the factory installation and operating instructions from Buick which contains the schematic. You explanation of the cap hook up is pretty much as I thought. I am awaiting a NOS vibrator; I do think mine is beyond help. I hooked it up (very momentarily!) directly to the battery and got nothing. I am sure it should have at least buzzed.

All: Big help. Makes me want to ask more questions: Agreed, buffers and filter (10 mmf/20 mmf) caps should be replaced. Filters look like electrolytics and just insert where those honking cans are in my chassis (Roadmaster71; looks like your 1st photo shows just one cap. Correct?) "Coffin" holds the poly "drop" non -electrolytics, correct? Schematic shows either end of secondary coil going to a reisistor, then to the buffer cap, and finally to ground. So, just make sure each poly connects to ground and solder the 2 other leads where the old ones were, correct? I hope these questions aren't confusing things! I do appreciate the good feedback so far.

Can anybody shed some light on working on a 1940 (980620) Sonomatic? I get nothing from the vibrator when energized, and most things I've read say that if the thing isn't buzzing while in circuit, it's bad., If I look at the schematic, there is very little between the power source (battery) and that vibrator. Any input appreciated! CD, Potomac, Md.

Does anybody have a schematic? I think I'll try recapping, as the tubes are good. Thanks, C Drake