Intermitent loss of electrical power/no start

Every so often, maybe once or twice a month for the last 6-8 months, my mother's 98 Bonnie will loose power. Here's what happens. She will get in the car in the garage, insert the key, and nothing will happen. She will have no power. No dome light, clock will reset and no start. She will leave the thing alone for awhile, 30-60 minutes. Go back and it will fire right off.

Battery had been load tested and is fine. Battery cables are tight at the battery and appear in good working order.

Would a failing starter/solenoid cause this kind of loss of electric power????

Thoughts, suggestions???

A starter or bad solenoid probally will not cause the problem.
I would look at the Right and left Maxi-fuse blocks on the firewall. Here is where the entire car gets it power from.
There is a cable that runs from the battery to the maxi-fuse blocks. If the retaining bolt is loose where the cable bolts to the block, this can cause an intermittant loss of electrical power to the car.

Thanks Merlin.

Soon as I get to NE I take a look at those things. It's really hard trying to diagnose this thing give that she's in SC Nebraska and in 200 miles away in SC KS. Uggh.

Thanks again!

Here's the story guys. Mom took the car to local dealer in NE. They diagnosed as a combination of a bad neutral safety switch and bad battery. The battery was load tested again and failed. A leaking cell I was told. Hmm. Go figure. I just hope it's fixed so I don't have to worry about her driving to and from NE to KS anymore.

Thanks for all your help guys!