I have a great 93 Eldo with the 4.9. Recently I have been having problems. I began noticing the fuel gage was having false readings and this was only the beginning. After about a month of this I noticed that when I turned the key off and waited about 30 seconds the analog speedometer would start to bounce up and down. Then a few seconds after that with the key still off the digital instrument cluster would turn on. Then a few seconds more the heater/AC. blower would turn on. Also the air ride pump will turn on and off normally. There are no engine codes being displayed. I diconnected the Heater/AC blower and found that if I wait until the digital cluster comes on after I turn off the car I can push the Display off button and it will stay off until I start the car again. Can anyone help me out? I have no idea whats up with the car.

 

Wow! That's a good one....can't say I've heard of anything like that before. It sorta sounds like a major problem within the cluster itself, or one of the electronic modules, but... It's like the ignition is not getting turned off completely, and those circuits are becoming "live" again. You may need to do some testing on the ignition switch itself. It's also possible there is a short in the ignition harness either in the column, or under the dash somewhere.
Is there any aftermarket systems/equipment(stereo, alarm, etc) on the car?
Do you happen to have the Service Manual for the car?