96 chevy lumina van something electrical

Lets see where to start... first the power locks went, then the dome light stayed on so we took out the fuse, then the car would just loose power every so often, like a car would if it was low on oil and shuts itself down so it doesn't blow the motor. The check engine light has been on since I purchased the van. But I couldn't put the van in the garage because I need it daily for my job. So, I was driving it one day and the light came on and said it was low on oil, but I checked it it was fine. Got the car to a stop sign made it through then it died and wouldn't start again. Changed fuel pump and now can't get any current to run through it. Put on computer and doesn't tell me anything, says something about electrical. Please help, I just put alot of money into fixing the front end and need the van to keep my job. I would appreciate any advice or suggestions.

Start checking wiring harnesses for loose connectors, especially the large bundles like the one the goes into the firewall near the steering column, it has all the fused power running through it. Sometimes the little "key" falls out of them, and they start working loose, causing all kinds of craziness.