97 Blazer Alternator/Dash/Running Light Fuse Problem

Checking up on this for a friend. He's working on a '97 Blazer (not sure on engine). When the battery is at about 8volts (jumpstarted) it will run ok with everything working. Once it charges to about battery voltage, it keeps blowing one 10 amp fuse. The fuse seems to kill the dash/running lights and alternator charging. Changing the alternator made no difference. Has anyone had similar problems or have any ideas on this? Any information on it is appreciated. -Kulluan77

Edit : Fuse blows randomly, holding as long as 2min before going. Battery voltage seems to be unrelated to fuse life.

check wiring make sure grounds are good and that nothing else is grounding out. does batery hold a charge?

start the car and immediately remove the positive terminal from the battery,(while it is running) leave it idle and see if the fuse still blows with the battery disconnected, do this and get back to me

Thank you for the quick replies. I will have him check and get back to you asap.

Isn't the radio/acc fuse supposed to be 15 or 20 and not 10? (correct me if I'm wrong on this) Also have you metered the voltage/amps to that fuse?

Little more info. It is fuse #4 "Gauges". When the fuse blows, you can hear the relays behind the glove box click once.

He went over the wiring checking for shorts, everything looked good so far. The fuse won't hold for over 2 minutes or so before blowing thou.

is the battery holding a charge or do you still have to jump it?

is the battery holding a charge or do you still have to jump it?

Only needed jump after running on the burnt out fuse for an extended period of time (no charge). Otherwise it is holding its charge (new battery also). The relay that is clicking behind the glove box seems to be a separate headlight turn on relay. He's going to look for his ampmeter to check that over more. Thanks again for the help too, I personally hate electrical problems. -Kulluan77