Citabria Battery charging problem

C

charlie hensley

New member
:( , :shock: :?:
We need help! Our 1971 7KCAB has an electrical problem. We were testing the starter solenoid with the wire to the starter disconnected. With the engine not running, we activated the starter solenoid and noticed that the Lamar B00371-14 voltage controller got very hot...hot enough to burn your hand through the firewall. The system (no surprise) no longer charges the battery. By shunting the voltage controller, the alternator puts out about 20+ amps. (indicating functioning alternator) What possibly could have caused the voltage controller to overheat. We have verified good grounds between the engine and fusalage structure and between the controller and firewall.

We have sent the controller to Lamar for checking but would really like to know if anyone out there has had anything resembling this situation or has any suggestions.

Prior to all of this we were having slow starting problems on cold days.
 
I had a battery charging problem that drove me nuts. It turned out after replacing the alternator, battery, votlage regulator and overvotlatage relay that the master switch was bad. The guy from Zeftrronics helped me figure it out.
 
JoeSF: ( :) )

Thank you for your reply. We have replaced everything except the master switch and the problem seems to be corrected. We think we had a short in the alternator that may have led to failure of the voltage regulator, over the last couple of years. We have had the voltage regulator repaired by Lamar, replaced the alternator, and installed a 5-amp fuse per the Champion electrical upgrade kit, in wire 17 in the switch panel. Everything is working (knock on wood) except we blew a fuse. We did not like the hidden fuse in the Champion kit so we have installed another fuse holder in the panel, and labeled it "charging circuit". We think this fuse should be a slow-blow but we are waiting for a recommendation from Lamar and/or Champion.
 
Charlie, I did the wire 17 fuse also. Thats an important one. I read of an accident because of that wire overheating a while back. I dont rememnbe if it was a fire, but its definatley a good idea to fuse that wire.
The Master switch cost me 16 bucks. It may be worth replacing anyway.
Joe
 
Joe:

Thanks for your reply. We may, per your comments, replace the switch during the next annual.

One of my partners accuses the other two of "if it ain't broken, fix it till it is" so we may hold off for a while.
 
Charlie,
Only problem with that is the problem can go away and then come back when Iyou really don't need it to. If it happens again check the master. It's the cheapest part! Good luck!
Joe
 
Hello there

I am just going through this headache right now. I replaced the generator a few months ago and the voltage regulator 2 days ago. I flew and tested the whole thing yesterday and the amps meter showed steady charging at 5 amps. Went flying today and for about 1 hour the meter was indicating slightly on the positive side that seemed to stabilize at zero. Has it stopped working again? tested the battery after landing and it read 12.4 volts. Is this not a little low? The liquid level in each cell seems to be on the low side barely covering the small metal plates...Could that be part of the problem?

Cheers

Bruno
Ft Smith, NT
1965 Citabria 7ECA (Continental 100 hp)
 
Hi again

Did some more testing today during a runnup. The battery is definetely not charging!

What is involved in replacing the master switch? Is it a big job? Where do we order this part from? ACA? Is there any soldering involved in reconnecting the electrical wires (Generator, regulator, etc?)

If the problem is the master as suggested earlier in this post, would it not affect everything else like starting, magnetos use, etc).
After all, if you turn off the master switch, you are not going anywhere....

As you can see, I am not an aircraft mechanic!

Thanks and cheers

Bruno
Ft Smith, NT
 
Bruno-

How have you confirmed that there is no charge?

It is very common with a well serviced battery to see little indication of charge on the ampmeter, as a result I installed a EI VA-1A digital volt/ampmeter. On my new GCAA I never had any indication of charge/discharge.

Tom-
 
Tom

I do have an amp. meter and during the runnup today, I turned all electricals on, (landing lights, nav light, radio, beacon). The amp. meter stayed on the negative side indicating that the system was drawing current from the battery but none was coming in. I checked the battery after engine shut down with a volt meter and it then showed 12.0 volts. Yesterday after my last flight it read 12.4 volts.

Also during the runnup, I tested the voltage through the cigarette lighter output and at 1700 pm, it only showed 12 volt output! Should it not read a little higher? I know at cruise speed, it should read about 14 volt but I did not get to take off as the weather is not good enough!

Help!

Thanks

Bruno
 
Bruno-

You have a 12 volt battery and a 14 volt alternator, since you are only showing 12 volts with the engine running I concur that you have a charging system problem not a battery problem.

With my VA-1A I see 13.9 volts anytime the engine is running, the amp load is dependant on the amount of cranking required for start and the number of electrial draws on-line.

Tom-
 
You can check to see if it's the alt. ,voltage reg or master switch.First verify that it is not charging with a volt meter. With the plane running and a draw on the electrical system it should be charging at least 13 volts after startup. If it reads battery voltage or less chances are it's not charging. The large wire on the alt."battery" should have voltage with the master on if not trace the problem to see why not it could be the master causing that. If it does have voltage check the type system you have, you should be able to bypass the voltage regulator and make the alt. charge wide open just don't leave it that way,if it charges like 14 to 16 volts the alt. is good. It could still be the over voltage relay which simply kills the voltage regulator. Anyway hope this helps .

Woodie
N29763
 
Thanks Guys

First the plane has a generator not an alternator...

Just before putting the new voltage regulator in a few days ago, the battery was charging at close to 25 amps which tells me the generator was working fine and not the VR. When I put the new VR in, it worked for a little while , first charging steady at 5 amps the first day, then just a bit on the positive side the second flight (1/2 amp) then it stopped registering.

Woodie, where is the voltage relay located?

The battery froze this past winter. Could it be damaged? How it would affect the charging problem? Why did it charge for a little while after I installed the new VR?

Cheers

Bruno
 
Bruno,
You might want to look at http://www.sacskyranch.com, they have a good written explantion of the generator charging system and how to check each part. I'm not sure where the overvoltage relay is it is usually located close to the voltage regulator, not sure if one is used or it could have been done away by someone in the past. You must have a O200 Cont. it would be a good time to convert to an alternator, generators are a pain to keep working at best.

Woodie
N29763
 
Several month ago, I posted a battery charging problem statement concerning a '71 7KCAB. We have messed around with the plane for about 6 mo trying to solve the problem.
A summary:
In '01,we replaced the original voltage regulator and overvoltage relay with an electronic unit manufactured by Lamar (B-371-12) and purchased through ACA for $300. The unit failed sometime between '02 and '04 due to unknown causes, resulting in hard starting and eventually no-starting.

We replaced the unit with another identical unit from ACA that only lasted about 2 min. ACA took the unit back and gratiously refunded our money.

Out of pure frustration, using the shotgun approach, we replaced the alternator. We also checked, very carefully, all wiring involved in the charging circuit. We installed the ACA recommended fuse (part of the electrical upgrade kit) in the circuit going to the controller.

To get the plane back together, we sent the original Lamar unit back to Lamar and they rebuilt it for about $100. This unit lasted about 1 mo and failed at which time all three fuses blew...the Champion recommended 5-amp and two 7-amp fuses in the Lamar unit.

Since then we have replaced the Lamar controller with a Zeftronics unit (15RVOL, I think) that is currently giving us good service with good starts and good charging.

Keep your fingers crossed. We still are not totally sure what caused all of this but we think it was probably bad carma and vibes between us and the Lamar controllers...they just seemed to not be happy in our plane.

For what it's worth...........
 
Thanks Charlie

I am presently focusing on the battery. We took it out of the plane yesterday, did a test load which showed a marginal status followed by a a hydrometer check on all the cells. 2 of the cells need complete recharge, 3 were fair and only one was ok.

I read earlier in the week on one of those "battery website", that a badly sulfaded battery can trick the voltage regulator into readind plently of power in the battery while there is not hence the VC shutting down!

I know the battery power level is very low right now, So I will put it back in the plane and see if it recharge next time I fire up the engine...

That battery froze this winter so I figure that I will give it due attention right now and see if that is the cause...

If not, then....oh well don't want to think about it today!

Cheers

Bruno
 
Bruno-

I would immediately replace a battery that was frozen, in my experience (obviously much warmer temps than yours) a charged batt never freezes so I will assume your battey was both discharged and frozen, a fully discharged battery is rarely reliable after recharge. That analysis is seemingly confirmed by the hydrometer test, all cells should be similar, to have one OK, three fair, and two discharged is a good indication batt replacement is called for.

Tom-
 
Thanks Tom

As usual I think you are right. I will get another one. Based on your experience, could that be a cause for the voltage regulator to play tricks on the charging status as I mentioned earlier....

Bruno
 
I just gleaning a question from in the middle of the thread:

When you say replace the master switch, you have 3 components to that. There is the switch on the bus bar. There is the power to the Master Solenoid, and there is the Master Solenoid itself. IMO, first suspect in these 3 guys would be the Solenoid. Is that the cause of your issue? I am not sure....just an elaboration of a question. Only the wiring is hard to replace. Solenoid is next to the battery whether you did Service Letter 418 or not.

As for Lamar or Zeftronics, I would say the Zef is as doomed as the Lamar was before. On new airplanes, its the brush skip in the new Kelly alternators that is causing small spikes and killing a perfectly good Regulator. (Animosity for Kelly errors omitted) Anyway, this can happen to older airplanes too. The Alternator is the most complex component in the charging circuit with the oldest technology. The rest is just wires, switches, selenoid....and the Voltage Reg. which being a solid state modern component is low suspect. I digress, just saying I trust alternators the least. :lol:
 
I replaced the toggle switch on the bus bar and my problem has been gone ever since. 16 dollars from American Champ.
 
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