i have a 1994 fullsize blazer. Installed new 200 amp alternator new battery still only shows 10 volts on gauge. Checked with multimeter actually putting out 13.6 which still isnt enough. Did the jumper cable thing with no change in readings so that kinda rulls out the wires. This all started when i installed a rebuilt starter from autozone. When i hooked the battery back up i heard a pop inside the truck and the check engine light immedianyly came on. Checked codes showing iac valve low voltage at pin 1 which would be a knock sensor and a code for fuel mixture. Thats also when the charging thing came into play. Checked all fuses and relays they are all good. Any thoughts guys? Could it have blown something in the onboard computer(ecu)?
also installed new iac valve cleared computer and its still showing iac code.
Installed new ecu still the same conditions
please any suggestions or thoughts would be appreciated.
Although anything is possible it is not likely. The first thing I would check would be for corrosion at the double stack positive battery cable ends. After that I would check the alternator ground and then the fusible link connections at the starter. All of the above is in order to correct system voltage and may not affect the code issues.