99 Blazer V6 4x4
Intermittent start problem
Start a few times then won't, no sounds/lights
Voltage read low
Charge battery and it's good for a few days
When the vehicle is running check voltage at the battery . should be 13.1 to 14.1 volts , if not the alternator isn't charging . Doesn't matter if the alternator is new , has to have B+ voltage on the heavier wire connected to back of the alternator . The other wire connected to the alternator comes from the PCM/ECM . Is the Battery symbol light on when vehicle is running ?
The powertrain control module (PCM) or vehicle control module (VCM) turns the generator ON or OFF, by applying voltage to the generator control/monitoring circuit 225 (RED). The regulator in the generator also requests the charge indicator located in the instrument panel cluster (IPC), using the same circuit. When the regulator monitors that either a voltage high or voltage low condition exists with the engine running, a ground path to the PCM/VCM will be provided through the generator control/monitoring circuit 225. The PCM/VCM then sends a serial data message to the IPC requesting the charge indicator to be turned ON. The IPC monitors serial data messages from the PCM/VCM, and turns the charge indicator ON when requested. It mite be best if you take your vehicle to a qualified repair shop , unless you like making parts stores rich , buying unneeded parts .
May 18, 2016 |
Cars & Trucks