Electrical Problems

[Hyflyer86]

Hi Guys:

Well, I have solved my alternator problems. After changing the front alternator, I still had warning lights. I pulled the warning/control box and replaced a diode. I calibrated the control voltage for front and rear alts. I replaced a bad wire on the firewall unit. All good.

After the mechanic changed the alt for me and powered up the system, the gear doors opened, and the warning horn sounds when you turn on the master. I have changed a couple of components in the warning box and the throttle switch on the front engine which was failed. Still horned.

I have jacked the plane, checked all up/down switches, squat switch, landing gear selector switch, and the up and down lock circuits. They are all good. Cannot get the doors closed. Could swing gear by putting power on the solenoid and operating the master but the gear would not lock up or down due to tripping breaker.(p-switch not in circuit with hot wire). I could lock the gear down with the hand pump.

Now, off the jacks. Not getting power to the solenoid through the pressure switch. Tracing the wire from the gear ind cb and lose it in the large bundle behind the panel. No continuity from cb to solenoid, p-sw at powerpack plug or ind lites, including Press to test. My LAN Cable tracer doesn't seem to work either. It loses power just after the connection at the cb. I think I am at wits end due to brain size.

Can anyone offer trouble shooting help? How about the contact info for an expert to come and solve it? Southern Oklahoma.

Bill Hyflyer86

[Red Air Rambo]

Hi Bill,
My 73 P model was having some electrical issues and it turned out to be a bad contactor. We ended up replacing all three due to age. I would check the voltage coming through the battery cable to the contactor too.

Brent

[Hyflyer86]

Thanks for the reply Brent. I do have power at the LG contactor but no power to activate it when commanded. I will check all of the contactors on my 73 -P too. Thanks again.

Bill Hyflyer86

[Red Air Rambo]

Just to clarify I was talking about the three main contactors located on the firewall beneath the pilots side cowl. There is a battery, front, and rear. In my case the battery contactor went south causing all kinds of strangeness.