supercub1999
Registered User
Having a doosy of a problem, not going to mention that I probably caused it by arcing something during the annual.. but anyway.. out of annual and my field is not getting to the alternator, a Cessna 310.
I have the problem solved I think, bad voltage regulator, have a couple test to confirm it's not the wiring or short in wiring into and out of the regulator, tested all other wiring. Power is routed through bus to one switch called Emer Field, than another switch Regulator Selector switch (only uses one and has a backup if main fails) than onto the voltage regulator, diagram below. I am almost positive the regulator is the problem, I have a new one today but want to confirm it its bad before installing new one. Here is what happens, the voltage regulator is showing battery voltage all the way to the field switch, but as soon as I close the field switch the voltage drops to 2 volts, but if I open the switch it comes back to battery voltage. Every time. It's not the alternator, I have tested it with a known good one in it now, ran new wire and new toggle field switch from the blue dot terminal on the Regulator Selector switch all the way to the alternator and still same problem, close the switch and voltage drops to 2, open it back to battery voltage. I thought the problem was forward of the field switch because the battery voltage always returns to good when I open the field switch, but after running a completely new wire and switch out to a new alternator and it still fails at the same place, I decided to back trace the bad voltage and it went all the way back to the blue terminal on the Regulator Selector switch, the red terminal is fine, never loses the signal there. That's when I decided to test the alternator unregulated by taking the green input on the left side of the switch off the switch and connect it directly to my new field toggle test switch with a 5 amp fuse between the alternator and test toggle switch, started up and hit the test toggle and bam alternator comes alive right up to 36 volts, that confirmed alternator is good. Shut down and ordered a new voltage regulator, have it today but just wanted to run this by someone with bad voltage regulator experience and see if this makes sense as to a bad regulator.. or could it be something else? I haven't tested all the terminal on the switch yet will do that today.
I tried testing the regulator and must have did it wrong because I got 0 output, I connected a wires strait off the battery on each terminal the pos and neg, hooked the pos to the vr input where the red wire goes, and the negative to the neg input to the vr, and checked voltage at the blue output and got nothing or close to it, was for sure not battery voltage.
I have the problem solved I think, bad voltage regulator, have a couple test to confirm it's not the wiring or short in wiring into and out of the regulator, tested all other wiring. Power is routed through bus to one switch called Emer Field, than another switch Regulator Selector switch (only uses one and has a backup if main fails) than onto the voltage regulator, diagram below. I am almost positive the regulator is the problem, I have a new one today but want to confirm it its bad before installing new one. Here is what happens, the voltage regulator is showing battery voltage all the way to the field switch, but as soon as I close the field switch the voltage drops to 2 volts, but if I open the switch it comes back to battery voltage. Every time. It's not the alternator, I have tested it with a known good one in it now, ran new wire and new toggle field switch from the blue dot terminal on the Regulator Selector switch all the way to the alternator and still same problem, close the switch and voltage drops to 2, open it back to battery voltage. I thought the problem was forward of the field switch because the battery voltage always returns to good when I open the field switch, but after running a completely new wire and switch out to a new alternator and it still fails at the same place, I decided to back trace the bad voltage and it went all the way back to the blue terminal on the Regulator Selector switch, the red terminal is fine, never loses the signal there. That's when I decided to test the alternator unregulated by taking the green input on the left side of the switch off the switch and connect it directly to my new field toggle test switch with a 5 amp fuse between the alternator and test toggle switch, started up and hit the test toggle and bam alternator comes alive right up to 36 volts, that confirmed alternator is good. Shut down and ordered a new voltage regulator, have it today but just wanted to run this by someone with bad voltage regulator experience and see if this makes sense as to a bad regulator.. or could it be something else? I haven't tested all the terminal on the switch yet will do that today.
I tried testing the regulator and must have did it wrong because I got 0 output, I connected a wires strait off the battery on each terminal the pos and neg, hooked the pos to the vr input where the red wire goes, and the negative to the neg input to the vr, and checked voltage at the blue output and got nothing or close to it, was for sure not battery voltage.
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