No start after replacing the batt under the seat.03 deville

1 Check batt for charge should be over 12V
2. Clean batt post and cable connections
3 Tighten cables
4 check for a burned out fuse link at batt wires small wire looks melted if so replace
simple stuff 1st Mike

Check your connections. Is batt in rear or front? If batt in rear may be an jump start terminal in eng compartment. Try a batt box jump from there. If nothing, conns/main fuse check should be next.

Cadillac codes are easy to read..then replace the bad sensors etc and then clear the codes and try again etc

check the drive belt condition and tension first as the initial tension setting may now be loose.

it is not a fuse, it is a circuit breaker in the fuse box, which i believe is under the hood on that car, i would check for bare or shorted wires behind the stereo before doing anything with the power seat.

Sounds like fuel issue, remove the black plastic cadillac cover on the top of the engine, then find the fuel rail on top, and remove the black tire cap looking thing on the end of the fuel rail. Now you will have to get a fuel pressure guage ($45), and screw it on right there. Or you can also just poke that little valve with a ink pen to see if any fuel squirts out, it should come out with alot of force, it is like a valve on a bicycle, it only lets fuel out when you push on the valve ***. As for the battery being dead perhaps you left your parking lights on? My 97 deville, had a cold start problem, that it took 5 minutes of cranking off and on, to get it cold started, but after it was running it would start throughout the day just fine. I ended up replacing the fuel pump in the tank, and the fuel filter on the rail.

CADILLAC HAS FUSES MOUNTED UNDER THE REAR SEAT OR IN THE TRUNK. RADIO FUSE SHOULD BE IN ONE OF THE FUSE CENTERS.

No fuse.These seats are protected with relays and a seat module.The module is under the drivers seat.There are 3 connectors and it would be hard to check all these wires for power to the motors.First look under the seat and make sure none of the connectors came apart under the seat by something that might have been left or rolled under it.The 2 main ones you can check are the connector 2 terminal C and connector 3 terminal A.C is a black wire which is ground and A is a red wire which is the feed power wire.Connector 2 is green and 3 is black.If the ground and power wires are good then you could have a bad drivers seat module.What I would do is go to the salvage yard and find a used module to try.Good luck.

BFC that body function controller. BFC batt fuse controls .the body function controller .its part of the PCM.the BFC controls anti theft system. your interior lights -drl lights- radio -door locks.if your check engine light is on take it to dealership.because your BFC and PCM works together. your car could shut off. that unsafe.when you on a busy highway.you have electrical problem.not a home fix.

let me assume u have not checked the fuses, meaning in al places the fuses are!, try,under the hood,under the dash and behind the panel behind the rear seat in the trunk, look in your owners manual for these locations and the particular fuse u have trouble with. good luck,hope we helped!