Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

Or, hide this message: temporarily or permanently

Test 11 - Power Transistor Testing

Wiring Diagram:




Wiring Diagram:







POWER TRANSISTOR SIGNAL CHECK






1. Check distributor connector for an input signal to the power transistor form the MPI controller by connecting the positive lead of a high impedance voltmeter to terminal 6 of the distributor connector and the negative lead to a good ground. There should be a fluctuating voltage signal when the engine is cranked or running.
2. If there is no signal present, check wiring between the MPI controller and the distributor for shorts/opens and repair.
3. If signal is as described and there is still no secondary output replace the distributor assembly.