Greetings!
My '81 Turbo Aztec has developed a Hot Left MAG (Bendix 1200 series) on the Left engine. Discovered the problem while doing an inflight LOP mag check; the engine was running fine. To says this squawk has us stumped would be an understatement. The Mag has just over 200 hours since it's last 500 hour inspection / tune-up. So far we have ......
* Checked for a broken P Lead. The wire going into the terminal at the capacitor looked a bit suspect so a new wire / terminal was spliced in. Still have the problem.
* Checked the Mag switch (internal contacts, broken wire, resistance). The switch is okay.
* Checked resistance of the wire(s) from the Mag to the Switch. All is normal.
* Inspected the Connectors (E302 and E348) for tightness, wire condition, pin/socket security and cleanliness. No faults detected.
* Checked the back of the Mag Switch / Starter panel for loose wires. Everything is tight and clean.
For troubleshooting purposes we've been testing (idling) the engine about 700 RPM. Turn off the Left Mag and nothing changes. L Mag on and Right Mag Off and the engine gets rough and drops 70 - 80 RPM.
Am wondering whether this might be an internal Mag problem? Hate to shotgun parts but we are about there. Since the engine is normally pretty smooth down to around 500 RPM idle, am wondering if the Left Mag only idle roughness might be the capacitor breaking down?
Even if there is a problem with the capacitor, not sure how that would cause a hot Mag?
Thoughts? Thanks.
My '81 Turbo Aztec has developed a Hot Left MAG (Bendix 1200 series) on the Left engine. Discovered the problem while doing an inflight LOP mag check; the engine was running fine. To says this squawk has us stumped would be an understatement. The Mag has just over 200 hours since it's last 500 hour inspection / tune-up. So far we have ......
* Checked for a broken P Lead. The wire going into the terminal at the capacitor looked a bit suspect so a new wire / terminal was spliced in. Still have the problem.
* Checked the Mag switch (internal contacts, broken wire, resistance). The switch is okay.
* Checked resistance of the wire(s) from the Mag to the Switch. All is normal.
* Inspected the Connectors (E302 and E348) for tightness, wire condition, pin/socket security and cleanliness. No faults detected.
* Checked the back of the Mag Switch / Starter panel for loose wires. Everything is tight and clean.
For troubleshooting purposes we've been testing (idling) the engine about 700 RPM. Turn off the Left Mag and nothing changes. L Mag on and Right Mag Off and the engine gets rough and drops 70 - 80 RPM.
Am wondering whether this might be an internal Mag problem? Hate to shotgun parts but we are about there. Since the engine is normally pretty smooth down to around 500 RPM idle, am wondering if the Left Mag only idle roughness might be the capacitor breaking down?
Even if there is a problem with the capacitor, not sure how that would cause a hot Mag?
Thoughts? Thanks.
