1193? Oldsmobile royal 88 Relay?

There is a chance that this is a ground problem, but probably not. Check all the big fuses in the power boxes under the hood. Not having a diagram, I am guessing that at least 1 or 2 send power to the other fuse box. The terminals on these fuses get a yellow or tan glaze on them which does not look bad, but if it is there, it may also be on the inside of the fuse sockets. This can suddenly bring an otherwise perfectly running vehicle to a dead stop...and not start. The first time I found it was on a Ford 18 passenger bus. Towed in dead. A fingernail file or womens emery boards will fit into these if trimmed and will effectively clean the insides of the socket. You can also try to fold emery paper, but it is not rigid and may be more difficult. Check the relays and their sockets also. Dielectric gel is a good idea when done, especially in a cold climate. I think it is a power problem of course since you say that nothing is on, but in the event that you can't find a contaminated fuse or relay, here is something else to check. Got this from a mechanic friend who found it on a 1994 Bonneville with a no start condition. We are now looking at grounding problems.On many of the Buicks, Olds's and Pontiacs, many of the wires from the dash and some from the engine compartment come together under the door thresholds...under the trim strip that guards the body and also holds the carpet in place at the doorways. These have lousy connections for bad weather climates, and the connections go bad and things just shut down. These grounds are some of the grounds for the under hood relays. You should really have a book with a wiring diagram. It can save you incredible amounts of time, especially if it is year and model specific.

There is a chance that this is a ground problem, but probably not. Check all the big fuses in the power boxes under the hood. Not having a diagram, I am guessing that at least 1 or 2 send power to the other fuse box. The terminals on these fuses get a yellow or tan glaze on them which does not look bad, but if it is there, it may also be on the inside of the fuse sockets. This can suddenly bring an otherwise perfectly running vehicle to a dead stop...and not start. The first time I found it was on a Ford 18 passenger bus. Towed in dead. A fingernail file or womens emery boards will fit into these if trimmed and will effectively clean the insides of the socket. You can also try to fold emery paper, but it is not rigid and may be more difficult. Check the relays and their sockets also. Dielectric gel is a good idea when done, especially in a cold climate. I think it is a power problem of course since you say that nothing is on, but in the event that you can't find a contaminated fuse or relay, here is something else to check. Got this from a mechanic friend who found it on a 1994 Bonneville with a no start condition. We are now looking at grounding problems.On many of the Buicks, Olds's and Pontiacs, many of the wires from the dash and some from the engine compartment come together under the door thresholds...under the trim strip that guards the body and also holds the carpet in place at the doorways. These have lousy connections for bad weather climates, and the connections go bad and things just shut down. These grounds are some of the grounds for the under hood relays. You should really have a book with a wiring diagram. It can save you incredible amounts of time, especially if it is year and model specific.