I have this problem, this weekend I changed my driver's side window motor. First time for that and it took me four hours! When I went to make sure that I had done it right, I found out that I had no electrical power anywhere. My window was in the down postion for almost a week so my first thought that someone stole my battery! But when I opened my hood,..my battery was still there. I thought that the battery was dead so I put it on my little charger for over an hour and the meter on the front said the battery was fully charged. After installing the charged battery, I tried to start the Blazer but there was nothing. Now my ignition key is locked in the switch. Is there a main relay or fuse that I might have blown? This my first Blazer as I normally drive cars and am not too sure of things.

 

Does anyone have ideas (other than to take it to a shop!)? It's a '97 4wd blazer with a 4.3 motor, LS model.

 

Have you gone over all of the fuses? Tested for power at the various main junction points with a test light or DMM?

 

I cheked all the fuses in the fuse block on the driver's side door. Using my neighbor's dmm, we checked various places where energy might be, ie; the three relays on the firewall, the three relays in the glovebox, horn relay, brake light switch. Nothing. Went to Autozone on the way to work and the store manager suggested an alternator repalcement due to a possibly faulty voltage regulator. After spending forty-eight bucks on three relays for the glove box, I said i'd have to think about spending another hundred forty bucks for the alternator. I am gonna have it checked first tho if replacing the three relays don't work.

 

A crapped out alternator would lead to a dead battery, but it would not prohibit power from getting to various points in the truck with a known good battery.

I also doubt that the relays have anything to do with the problem as it sounds much more basic. Start at the battery and follow the positive & negative cables testing for power & ground at any junction points along the way.

 

After replacing the three relays in the glovebox, it's like you said. Did no good. Spent some money, but now at least I can rule them out. I guess it's time for me to get down and dirty tracing the power leads from the battery like you suggested. Thanks for the help, I really appreciate it. I'll let you know what I find, it might take me some time.

 

Let us know if we can be of more assistance. I have gone wire by wire, junction by junction before and it isn't a task I really want to do again. Sometimes there is just no other way to find a systemic wiring issue.