1993 Roadmaster headlights suddenly stopped working

Mike18xx

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I assume this is a fuse or related electrical problem since it's unlikely that both headlights croaked simultaneously. Neither low nor high beams work.

Which fuse(s control the lights on a '93 LE? Anything else it might be?

Lay it on me, and I'll let you know what worked.
 

Mike18xx

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There does not appear to a fuse directly controlling the headlights.

Where would that circuit-breaker be? Thanks....
 

ryenie

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The 93 uses fusable links, I still think there is a fuse for the system as well as the in-line fuse. The circuit breaker is an internal part of the headlight switch. Not sure if it matters at this point, but do you have sentinel (automatic) headlights?
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ryenie

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Fuse 14 & 17, both 15 amp fuses are for the headlight system (not sure which fuse box). I think the fusible link is from the battery to the fuse panel box, and if it were bad there would be more than one effected circuit. It's supposed to be mounted somehow to the base of the relay bracket (which also has spark control module mounted to it). Had two wiring diagrams, one for with sentinel and one for without. The sentinel system typically keeps the headlights from turning off when it goes out. If the fuses aren't bad I would check the headlight switch next.
 

Mike18xx

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None of the fuses seem bad.... I switched around the 15s, and nothing stopped working that was or started that wasn't.

Note that I normally never mechanically turn on the lights; the sentinel system does it all.

Where specifically is the "headlight switch" with sentinel? (I'm really hoping this won't require me to tear apart the dash.)
 
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ryenie

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http://www.vadengmpp.com/owners-manual/buick/1993-Buick-RoadMaster.pdf Page 99 and 100 of the owners manual should explain the light switch. The sensor is in the vent on top of the dash, it could be bad, you may also have to have the headlights on for the brights to work, something i found out about my car not too long ago. You need to try and turn them on manually and verify that it's the headlights not coming on and not just a bad sensor for the sentinel setup.
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Mike18xx

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That's odd: I haven't had to touch that thing in years...strange it could have somehow be responsible.
 

tdw

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There is module involved withe twilight sentinal option that has bad solder joints on relays installed on the board.
If you have rotated the horizontal wheel all the way to the left to defeat TWS on the bottom of the light switch
and get lights head and tail lights using the lever switches above suspect, that module. The module is located
below the steering column near the firewall and I dont think new ones are available but resoldering works.
HTH
 

Rebmob_7577

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Keep in mind that the Twilight Sentinel May also cause weird issues with the headlights coming on and not the dash lights or vice versa. It was not a fun drive of 90 miles with no dash lights just to find out it was a bad solder. A quick re-solder, and the system acted good as new. Haven’t had to mess with it since.

Plus, see if your lights turn on manually, as I’ve heard stories about the Sentinel wheel defaulting to off while the plastic bit hadn’t been touched in years. May as simple as turning the wheel a bit to the right.
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