Jeep Grand Cherokee 2003 Limited - Starting Issue and electrical issues

I live at sea level in San Francisco and my Jeep Grand Cherokee just got about $3500 worth of repairs to basically replace the radiator and cylinder #1 from the San Francisco Jeep Dealer here in the city. This repair was done at New Years 2008.

After I got the car back, it seemed fine. So about 3 days later, I drove it to Lake Tahoe (~6200 ft above) and it seemed to start slowly on occasion. After returning to the city, it went back to starting fine.

About 3 weeks later, this past Friday, I returned to Lake Tahoe and the slow starting issue returned. But, now, it actually would not start after running for about 10 minutes or more. After resting for several hours, the Jeep would turn over.

So this past Saturday, the weird thing is that it wouldn?t start at one point, so I put it in neutral and pushed it out of the parking spot to get a jump. Without even putting the cables on the other car, I tested starting it and it started fine. After driving to the auto parts store, I had the battery tested. It passed with 3x the power to start it. He recommended cleaning the battery terminals, which I did.

Sunday, it started slowly again on 3 occasions. Then, last night, when getting gas before the 190 mile trip home, it wouldn?t start after I got gas.

So, I asked someone for a jump and when I hooked up the battery, the car lit up immediately. After topping off the battery with water, it took about another 5-10 minutes to start.

So, I ended up making the attempt home with some weird things happening to the car. i.e. the buttons on the message center would blink occasionally (about 6 times I counted in 4 hours) and when I turned my high beams on, all of the dashboard warning lights lit up.

Anyway, I turned off all radio, heat, etc and made it back to SF driving 55 mph the whole way. I got home, turned it off.

I tried to turn it back on, the transmission light went on, and that is it. No sound at all when I turned the key, like the car was completely dead.

Monday morning, I tried starting it and again, nothing.

A buddy of mine had a somewhat similar issue with his Cherokee and a ?a safety locking

device for the shifter?.

I guess the question would be:

What would short out the starting and give power surges while driving?

He recommended cleaning the battery terminals, which I did.

Did you do both ends of every cable?

I am thinking it may be the switch or wiring. Those can be difficult to pin down. Maybe someone who really knows Jeeps may have a specific suggestion or two.

It has the earmarks of a problem with main power connection(s), or, grounds. Disconnect the negative battery cable. Follow the big red battery cable down to the starter motor. Loosen the hold down nut, on the starter, a couple of turns and re-tighten. Follow the other red cable from the battery positive to the Power Distribution Center. Open the cover and loosen and re-tighten all the nuts, or screws, attaching the wires to the PDC
The wire from fuse #14 (40A) goes to the ignition switch to power a lot of stuff. Double-check its integrity.
The wire from fuse #8 (40A) goes through the engine starter relay to the starter solenoid. (Both wires distribute to other circuits, also.)

Loosen and re-tighten the battery ground cable where it attaches to the car body and, or, engine. Do the same to any other ground wires you can find.

JEEP have had lots of problem at the battery terminals. I would change the terminals, it goes bad where it meets the wiring which you cannot see. if the battery tested ok.