98 s-10 Blazer When i take my foot off gas pedal or in idle battery power goes down.

S-10 Blazer When I take my foot off the gas pedal or if it is in idle the battery power goes from 14 to around 10 or 11. I put in new battery and had altenator tested and was fine. Any suggestions to try next? The new battery made it start better and alot easier.

S-10 Blazer When I take my foot off the gas pedal or if it is in idle the battery power goes from 14 to around 10 or 11. I put in new battery and had altenator tested and was fine. Any suggestions to try next? The new battery made it start better and alot easier.

If you have a voltmeter, check the alternator output at the battery terminals with engine running. If reading is under 13 volts, alternator output is bad.

Measure the battery voltage with the engine not running. Battery voltage should be between 12 and ~13 volts. If less than 12 volts, battery is bad.

my mothers 98 olds bravada (lux verson of blazer) does that too. i think the idle is set to low cause it runs about 500 rpm and i believe it should be 750. if you lightly press the gas pedal and get the rpms to 750 the volts run back up to the 14 range. when idle on own (500rpm) it tends to run 10 volts or even less depending on what all is running. there is a torx screw on the bracket with the throttle cable if your rpms are lower then 750 turn the screw it till it reaches that range.

my mothers 98 olds bravada (lux verson of blazer) does that too. i think the idle is set to low cause it runs about 500 rpm and i believe it should be 750. if you lightly press the gas pedal and get the rpms to 750 the volts run back up to the 14 range. when idle on own (500rpm) it tends to run 10 volts or even less depending on what all is running. there is a torx screw on the bracket with the throttle cable if your rpms are lower then 750 turn the screw it till it reaches that range.

Dash volt meters are not always true.
Always check voltage at battery with a volt meter.