Lamar Voltage regulator

[akloon]

My oil temp gauge and ammeter started bouncing in unison to some heavy rap beat I couldn't hear last flight. Fortunately, while I was trying to figure that out and fly, my passenger (a AI) did all the troubleshooting and determined that it had to be the voltage regulator. I just replaced it last year or so when it caused my alternator light to come on. (ammeter showing a charge, altermator light working).

Would anyone else offer a different suggestion, and if not, has anyone tried to switch to a Cessna part that doesn't cost $250 or so?
Dave

[aero101]

http://www.aircraftspruce.com/catalog/e ... ontrol.php

Aircraft Spruce has cheapest regulator around, but normally they're pretty reliable and long lasting? Have you checked the brushes in alternator? If regulator bad already I'd suspect something else is contributing to the failure...

[akloon]

I took the alternator in last year when I did the other replacement and it checked out. Thanks for the link.
Dave

[YELLOWMAULE]

Kelly Aerospace........NOT!

[aero101]

I did the same with a lamar system that was giving me grief, it checked out good on their machine but problem continued after a new regulator. Finally I pulled the brushes out and they were worn down to a nub, new brushes were about $10 at NAPA, compared to price of regulator that it didn't need???

[akloon]

I'm not sure what the Kelly Aerospace jibe was conveying, I'm a little dense. Did you have trouble with their regulator? Specifics?

Copy on the alternator check out. If I r&r this part and it doesn't check out that will be my next step. What were your indications?

[aero101]

If I remember right, when doing the resistance test of alternator field / stator, it would check good in some areas of rotation, and high in others. Here's a good TS guide... good luck!!

http://www.us-doc.com/14V%2BELECTRONIC% ... LER_442386

[YELLOWMAULE]

Sorry Loon,
I was being petty. I am still languising under the poor treatment I had been subjected to a couple years ago by that company. Never mind me, I'll get on with it...
How are the skis working out?

[akloon]

thanks for the TS guide, I'll check it out

The skis are pretty sticky compared to strait Landis 3000s, but I guess I expected that. I haven't taken them into the deep stuff yet, I may wait until next year when I put some expanded bottoms on them and fill in the back. It is really nice to have the wheel option though.

[andy]

I went through a somewhat similar experience with my 1986 MX-7-180 except that the voltage fluctuations caused my JPI EDM-800 and Apollo GX-60 GPS/Comm to restart randomly in flight. I replaced the alternator control unit but it ultimately turned out to be an alternator problem. Check the resistance of the field connections with the wires disconnected while someone turns the propeller. If the brushes are ok, you should get a fairly constant resistance throughout the rotation. I think it's supposed to be less than 100 Ohms. Otherwise, the brushes are glazed and you'll need to have the alternator serviced or replaced.

Andy

[akloon]

What has been the typical life of an alternator?

[belandd]

Check your wiring. It is not rap music. It is not likely your alternator or regulator either.

Use a quality multimeter to check for voltage while running, voltage under load and resistance with everything off and then everything on.

I found a similar problem caused by a bad circuit breaker for the alternator.

If you want to throw money at it, let me know and I will take some.

[aero101]

You can totally eliminate the regulator very easily by disconnecting and running a jumper to the alternator and running engine... The brushes in this alternator are a common problem and the alternator will check good on an alternator bench because they just spin it and test voltage out without a load. As Andy stated the brushes can be eliminated very easily as well with an ohm meter while slowly turning to check resistance. Both these items can be checked and eliminated in about 20 minutes after engine uncowled and it they check good, you have a wiring problem that could take hours to find? Brushes are about $5.00, regulator +$200.00, I'd wouldn't just start throwing parts at it unless you've got too much money, and I'd like to get in that line as well

[belandd]

I looked on several other aircraft forums and found similar problem.

Most common fix was master switch.

I know it is a pain to try and troubleshoot a "simple" airplane but the key is to isolate the components until you find the one that is causing the problem.

I had an problem with a C170 that would not deliver voltage to the main bus. After the owner changed the regulator he brought it to me and to our surprise we found it to be the circuit breaker.

Lesson learned. Trouble shoot systematically and keep notoes on what you have done.

Call any time akloon.

[a64pilot]

What has been the typical life of an alternator?

A new one should last until TBO, so 2,000 + hours?