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One more bad Voltage Regulator

I did measure the yellow wires..but to groung, not between them?? I got 9.7volts AC...Can measure again if that is not correct way?? I'm baffled, if I get any voltage I can't imagine that I forgot to hook a wire up or hooked it up incorrectly???

Go back and read my post 191. Measure AC voltage BETWEEN large yellow wires to verify good alternator output.
 
Dick,

These instructions are assuming you have a meter, a very limited knowledge of how to use it and no troubleshooting ability.

1) First double check the Regulator wiring. Look at the Rotax regulator plug.

a) The two heavy gauge wires from the engine go the two ?G? positions.
b) The two White wires go to the ?R? and ?B? position.
c) There is NO wire in the ?L? position.
d) The small yellow wire goes to the ?C? position.
e) The plug is FULLY seated, all connections are FULLY seated.
f) The Regulator is bolted to the airframe

2) Setup the meter;

a) Connect the Black lead to the meter COM, (-) or BLACK socket.
b) Connect the Red lead to the meter V, VOLT, (+), or RED socket.
c) Do not connect any lead, to any socket marked A, AMPS, or MA.
d) Turn the meter on
e) Select DC volts.
f) If it is not auto scaling, select a range that includes 10-15 volts.

3) Connect the Black meter lead to a good ground.

4) Test the meter and ground connection by checking a known voltage with the Red lead, the battery (+) lug. This should read positive (+) 11-13 volts. If not at 11-13 volts, stop now and find out why.

5) With the Master Switch on and the engine NOT running, with the Red Meter Lead, measure the voltage at;

a) the Regulator B pin _______
b) the Regulator R pin_______
c) the Regulator C pin_______
d) the Regulator case________

6) Start the engine and run at idle speed, with the Red Meter Lead, measure the voltage at;

a) the Regulator B pin _______
b) the Regulator R pin_______
c) the Regulator C pin_______
d) the Regulator case________

After answering these questions there may be more tests. But we have to start here.
 
Test

Thank you Mike for detailed testing procedure..I will go up this morning and follow to the letter....hard part is running and testing since I have to be upside down under panel..but wil give it go again...Dick
 
Testing

Tested per Mike's instructions: engine off- B pin=.175 volts DC R pin=12.6 volts DC C pin=.165 volts DC case to ground 000
Then with engine running at idle- B pin=5.01 on one yellow wire and 3.4 on other yellow wire DC R pin=12.6 DC C pin= .314 vots DC and case to ground 000
This test was done with Best Fluke Mutlimeter...Now what??? thanks Dick
 
Pins B & R should have identical voltage. Why they are different is puzzling, unless you made a mistake reading the meter or writing down the voltage. But of even greater concern is the voltage on pin C. It needs to have battery voltage on it or else the regulator will not work.
I would concentrate on the small yellow wire connected to regulator terminal "C". Tug on the terminals to be sure that they are tight. Follow the small yellow wire to make sure it is not broken. That wire connects to several places behind the instrument panel. Check every small yellow wire connected to Van's boxes, making sure connections are good.
 
Yes, Joe is correct as usual.
Dick, did you confirm the wires are in the correct locations on the Rotax plug? Are you sure the small yellow wire is in "C" position and there is NO wire in the "L" position?
 
The reason that I asked about the master switch light is that the small yellow wire on regulator terminal "C" gets its power from the master switch. The light being on tells me that the circuit is complete through the master switch.
 
Dick,
Here are a couple of wires to check:

A 39" yellow wire connects regulator terminal "C" to AV-50000A firewall D-Sub pin 21.

An 8" yellow wire connects AV-50000A ignition D-Sub pin 14 to
AV-50002 ignition module D-Sub pin 14.

Make sure the D-Sub pins are not pushed back out of position.
 
Question??

So is not the single small yellow wire just a sending wire to tell what is being charged/discharged at voltage regulator?? if so why am I getting any voltatge indication if it is not connected?? Same with other wires..yellow wires reading less than 12 volts..seems to me that If a wire is connected it will either read or not??? Dick
 
That small yellow wire has two functions:
1. It enables the regulator.
2. It tells the regulator what the aircraft system voltage is.

The Fluke meter needs to be set to AC for checking the two big yellow wires and the engine needs to be running. And AC voltage needs to be measured between the two big yellow wires, not referenced to ground. At above idle RPM, I expect the AC voltage to be more than 20 VAC. There is not much to go wrong with the Rotax generator. It has no moving parts except for permanent magnets in the flywheel.

The voltage regulator contains semiconductors that will leak some voltage between regulator terminals. Therefore terminal "C" will have a little voltage on it even if the small yellow wire is broken someplace.
 
Joe, how about having him run a temporary jumper from the C terminal to the plus side of the battery? Then make a short engine run to see if the DC voltage comes up. If it does, as I suspect it will, we will know that the problem is in the C circuit somewhere for sure. Thoughts?

BTW, you going to OSH this year?
 
John, That is one method of troubleshooting, but it comes with the risk of damaging equipment. It also depends on what your goals are.
In this case we know there is no power, so jumping it out may get it to work, but you have to find the open connection anyway. Why waste your time with the unnecessary step, while taking a chance on causing damage?
 
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Test

O.K. I have never tested between the two big yellow wires always to ground..and last test suggested DC on Multimeter...I made some long pigtails I can hook to yellow wires and run engine (with canopy closed) instead of my legs hanging out...and run the RPM up...
 
John, your suggestion has merit. But I agree with Mike Miller. If there is no voltage on terminal "C", it needs to be fixed.

Dick, the advice to set the Fluke meter to DC was correct for measuring DC voltage on terminals B and R and C. For measuring AC voltage on the "G" terminals, the meter needs to be set to AC. It is unlikely that there is more than one problem. Since there is no appreciable voltage on terminal "C", that problem needs to be fixed. Whether or not the generator is working has no affect on power going to terminal "C". Fix the small yellow wire.
 
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small yellow wire

O.K. headed to airport, will take top of panel off..many screws and chase small yellow wire..sure hope I find something not connected properly...thanks for all the help...Dick
 
A troubleshooting method that I use sometimes is to connect the red meter lead to an Exacto knife blade and push the blade through the wire insulation to contact the wire, keeping the blade orientated so as to cause minimum damage. If you use this method, take care not to short out the wire to ground. It might be difficult or expensive to replace the hidden 1 amp fuse.
 
One More

Just to add to the already long list...RV12 regulator gone after 775 hours. As recommended often, eliminated all wiring and generator possibilities leaving only the regulator as a suspect.

Initial concerns came with starting difficulties. Battery was finishing flights below 12.5 and barely reached 13 at anytime during flight - even dipping into the low 12's during flight.

I live in an extremely warm part of the country so diffusing heat from a regulator is extra hard. Plus I have lights, etc. I did install the "fin cover" originally during the build as recommended by Van's and since it lasted almost 7 years I would be hard pressed to say it didn't help.

I did not move mine to the cockpit for all the reasons mentioned by others. All in all 7 years, almost 800 hours, I can't complain.
 
Tested

I ran engine and checked AC voltage between yellow wires and it was 20 volts at idle....then I once again checked the voltage DC on the small yellow wire and no voltage...then took top panel off and followed long yellow wire back to EMS plug and checked it all the way and made sure it was mated in plug..then chased small yellow wire from EFIS plug to EMS and made sure they were connected..still not voltage at yellow wire and no charging going on when engine running which I surmise is the fault of no voltage on yellow wire but where next?? at least I know the generater/Alternator is good...thanks
 
Dick,
The regulator terminal "C" wire does not go to the SV-EMS-220 or SV-D1000. Please use the same terminology as shown on Van's plans. Otherwise you will be thinking one thing but I or others will interpret it as something else.
It will not be necessary to run the engine for any more tests. You have narrowed the problem down to lack of voltage on terminal C. You surmised correctly. That voltage comes from the battery. Since a visual inspection does not reveal anything obviously wrong, it will be necessary to troubleshoot using your Fluke meter. Check the two wires that I mentioned in my post # 211 above. First step is to measure the voltage on that 8" solid-yellow wire that connects to the AV-50000A ignition D-Sub pin 14. The easiest way to do that is by penetrating the wire with a sharp blade. If you do not want to damage the wire, then remove the back-shell from the connector and try to test the pin with the meter probe. If you do remove the back-shell, also measure the voltage on pin 13 (white/yellow) while you have it apart. Neither end of the 8" harness can be disconnected for these tests. To make sure that you have the correct harness, there should be 11 wires (plus shields) connected to a 15 pin D-Sub.
You are making progress now.
 
Dick,
After posting last, I thought of an easier test: check continuity using the Fluke ohmmeter setting (set to lowest scale if more than one).

The master switch should be OFF for this test.

Remove the D-Sub connector from the AV-50002 "Ignition and Start Module". Check continuity from socket 14 to the regulator end of the small yellow wire.
 
I just finished installing my Amazon knock off regulator and it is working fine. I made a mounting plate from 3/16 aluminum. I took the Ducati and traced it's footprint on to the aluminum, cut it out and match drilled mounting holes for the old one, then a pair of holes for the new one and it bolts right in. I found a piggy back 1/4" push connector and even used all of the wires. It is charging at full rpm approx. 14.6 volts. Best of all? $30 with shipping!
 
just for fun

Today after doing all the testing with no great results, I put the John Deer regulator on and ran engine...no difference..still not charging...but for sure it's not the regulator...and the two yellow wires are putting out 2o volts AC so that is not burned out...not just to get it to charge...Dick
 
Dick,
Shut off master switch if it is on.
Remove D-Sub connector from back of AV-50002 IGNITION & START MODULE.
If the schematic is correct, it should look like the picture and have female sockets, not male pins. Looking at the picture, find the second hole from the right in the top row. Measure the continuity from that socket to regulator terminal "C". Call me with the ohmmeter reading and we will find the problem. Just to make sure our test procedure is not faulty, also measure continuity from the socket on the very right side in the top row to ground. Tell me what that is too.
1198.Jpg
 
I just finished installing my Amazon knock off regulator and it is working fine. I made a mounting plate from 3/16 aluminum. I took the Ducati and traced it's footprint on to the aluminum, cut it out and match drilled mounting holes for the old one, then a pair of holes for the new one and it bolts right in. I found a piggy back 1/4" push connector and even used all of the wires. It is charging at full rpm approx. 14.6 volts. Best of all? $30 with shipping!

Sounds great Dave. I have never seen over 13.8 with my original regulator, but I think the Odyssey battery may like the 14.6 better. What is the descriptor of the until that you found at Amazon?...........Tom
 
912ULS regulator failures.

I'd be happy to offer some input. Keep in mind I have not read this entire thread. The regulator is a good part. We have thousands and thousands of hours on them without failures.
First, the rotax manual clearly states that if the R-B regulator terminals are hot and C is open, permanent damage may result. I have ran into 2 failures do to 12v failure to the C terminal. I have contacted Vans and am awaiting for a reply from their engineering to track down the system failure as I am not able to track the exact path through their box via the online schematic. From what I have discovered is that avionics switch controls the 12v input to the regulator C terminal. IMO, this would be a bad thing do to. As it offers the pilot the opportunity to isolate this input resulting regulator damage. As a authorized Rotax repair center. And have done dozens of firewall forward 912ULS designs and installations. My solution until Vans engineering offers one. Is to take the regulator C terminal to the normally open side of the master relay for its 12V source. This offers a better solution then parallel R-B-C as per the Rotax manual, because this isolates the regulator from the battery when master is off. Which will result in a slow battery bleed from the diodes in the regulator. I have done this on 2 RV12's with 100% success. I hope this helps some. I will follow up when I hear back from Vans engineering.
Scott
 
Scott (Aircore),
Actually, in the RV-12, the regulator "C" terminal is connected to regulator terminals B and R though through one half of the DPST master switch. The avionics switch is not part of the regulator circuit.
Bypassing the master switch by connecting directly to the N.O. side of the battery contactor creates a safety hazard by not giving the pilot a way to shut off the rectifier/regulator in case of smoke in the cockpit.
I am very familiar with the RV-12 electrical system and can help you with troubleshooting. I can email you an electrical schematic that is much easier to follow than Van's wiring diagram maze.
 
Another failed regulator

For the record, my VR, mounted under the deck in the cockpit, failed at 130 HOBBs hours, 1 year 2 months after certification. I have replaced it with the same OEM unit. Now that it is in I see it showed signs of failure ( reduced charging amps) over the past few months I will now watch for.
 
For the record, my VR, mounted under the deck in the cockpit, failed at 130 HOBBs hours, 1 year 2 months after certification. I have replaced it with the same OEM unit. Now that it is in I see it showed signs of failure ( reduced charging amps) over the past few months I will now watch for.

My Ducati failed same way - acted up and then total fail at 110TT. Installed John Deere VR six weeks ago "under the hood" in original Van's location. Works great. Bought spare for $29 just in case...
 
I bought the Chinese clone of the JD regulator ($30 from Amazon of Fleabay) to keep on hand. I may try it out to see if it does better than the anemic 13.4-13.5 V I see during flight. Even if the original never fails, I suspect that charge voltage is probably not doing my battery any favors.
 
I like Dave12's mounting method using 3/16 aluminum. No modification of the the airframe is required. All drilling is done to the 3/16" mounting plate, not to the firewall. I assume that he countersunk the holes for the J.D. regulator and used flat head screws so that the adapter plate sits tight against the firewall shelf.
 
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I like Dave12's mounting method using 3/16 aluminum. No modification of the the airframe is required. All drilling is done to the 3/16" mounting plate, not to the firewall. I assume that he countersunk the holes for the J.D. regulator and used flat heat screws so that the adapter plate sits tight against the firewall shelf.

Good assumption. Don't know where that idea came from;)
 
I removed the John Deere regulator and put the original Ducati regulator back in my RV-12 for the following test. I disconnected the small yellow wire from the "C" terminal. Then connected a wire from the load side of the battery contactor to terminal "C". Now my plane was wired just like Aircore wired OlderThanDirt's plane. I went flying and turned off the master switch. As expected, nothing changed. Everything electrical kept right on working. Shutting off the master switch had no affect. There was an intermittent high voltage alarm. Jumpering the regulator control circuit should not be done. Any plane wired this way should have a placard stating, "MASTER SWITCH INOPERATIVE DURING FLIGHT". Back on the ground, I put the John Deere regulator back in and wired it the correct way. An analysis of the downloaded Dynon data showed a maximum voltage of 14.7
 
I made a mounting plate today. I had some excess .125" stock and cut it to the general size and shape of the Ducati regulator. Drilled two mounting holes. Now I needed a way to mount the new regulator to the plate. I didn't have any countersunk screws long enough, but I did happen to have some AN3 bolts that were exactly the right length.

I had a 1/2" rivet shaver bit that I never had a use for, and being far too lazy to write code to do the work on my CNC router I just chucked it in the drill press. I used it to (slowly) counterbore two recesses for the bolt heads, then drilled through the centers. Voila! A new regulator bolted to a plate that will bolt in place of the original regulator, using the original hardware.

IMG_1191.jpg

IMG_1192.jpg
 
THANKS DALE - -

I like it. I bought one of those reg to have just in case. When it is cooler, I will 'borrow' your idea. Good job.
 
Dale,

Could you tell me the hole spacing for the JD regulator? I'm going to put in an extra nut plate to account for the difference in dimensions.

Thanks!

Mitch Garner
RV12-120260
 
John Deere regulator adapter plate. Only one hole is countersunk. The forward
end of the JD regulator is bolted to the existing firewall shelf nutplate.
All John Deere regulators might not be the same, depending on the manufacturer.
John%2BDeere%2BAdapter%2BPlate.jpg
 
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I test ran the engine after installing the new regulator. It had been running 13.7 V max even in cruise flight and fluctuating a little, and lower at idle. Now it's at 14.2 V from 1800 RPM up to 4000, rock steady. I'll pack the Ducati as a backup just in case, but I like the fact that I didn't have to cut any wires and can revert at any time.

My level of trust in Chinese electronics design and manufacturing is just as low as it is in Italian electronics design and manufacturing, but at $30 a pop I can justify ordering a spare JD regulator to keep on hand even if I never need it.
 
Measurement needed

Hello, does anyone have the hole pattern measurements for the Ducati regulator? I need measurements of center to center of holes. I'm about to build a plate as described in previous posts. Thanks
 
From drawing in my post 244 above, 4.25 minus 0.625 = 3.625"
Confirmed by measuring hole spacing on the Ducati regulator.
 
Quick follow-up. In the past, whenever the plane had been sitting in the hangar for a week or two I'd generally see the battery resting voltage at around 12.5, or roughly 75% charge. That's generally not a good sign, and I was worried that I was about to need a new battery. A few days ago I stopped by the hangar, because it had been parked since my return from Oshkosh. Out of curiosity I poked the meter leads under the cowl... 12.8 V, or close to 100% charge.

I do get a little more noise in the headset with the JD type regulator. It sounds like it could very well be switching noise from the regulator. It's not objectionable, but noticeable. The next time I have the upper cowl off I'll probably see if adding a capacitor helps or not.
 
Thanks

Thanks Joe, I just misread your simple drawing. I was thinking 4 holes and you did it in 3. Got it now.
 
I can understand that after looking at Dale's picture. After I made that adapter plate, I think that it would be easier instead to install two new nutplates on the other side of the rudder channel. The disadvantage of doing that is that it will make more holes in the firewall.
 
My goal was to not have to install any more nut plates, or order a long bolt. I used the original mounting bolts and some AN3s I happened to have on hand. So basically I did it that way because I'm cheap and lazy. :)
 
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