Compulsion Posted October 7, 2013 Share Posted October 7, 2013 I was flying a 3 hr cross country today in my Jab170c. Everything was going great until I noticed the voltmeter had dropped below 12 volt and obviously not charging. By the time I got to my home field YGAW I didn't have enough battery left to make radio calls. I figure the battery is probably fine and I have got it at home on charge. I expect the alternator is not charging. I have no experience with aircraft alternators and was hoping for some advice on where to start. I don't know if this has anything to do with it but I noticed my oil pressure gauge needle was not steady. All help appreciated. Link to comment Share on other sites More sharing options...
Jabiru Phil Posted October 7, 2013 Share Posted October 7, 2013 Could be the battery that is U/S. otherwise you should have seen the ALT light on. Had the same happen in my 230 a few months ago. New battery and all OK Phil Link to comment Share on other sites More sharing options...
Compulsion Posted October 7, 2013 Author Share Posted October 7, 2013 Thanks Phil. Nearly came over to Loxton today. Where would I go to get a new battery. Someone said the battery man on Hanson rd might have something. Link to comment Share on other sites More sharing options...
ruffasguts Posted October 7, 2013 Share Posted October 7, 2013 I was flying a 3 hr cross country today in my Jab170c. Everything was going great until I noticed the voltmeter had dropped below 12 volt and obviously not charging. By the time I got to my home field YGAW I didn't have enough battery left to make radio calls.I figure the battery is probably fine and I have got it at home on charge. I expect the alternator is not charging. I have no experience with aircraft alternators and was hoping for some advice on where to start. I don't know if this has anything to do with it but I noticed my oil pressure gauge needle was not steady. All help appreciated. I was flying a 3 hr cross country today in my Jab170c. Everything was going great until I noticed the voltmeter had dropped below 12 volt and obviously not charging. By the time I got to my home field YGAW I didn't have enough battery left to make radio calls.I figure the battery is probably fine and I have got it at home on charge. I expect the alternator is not charging. I have no experience with aircraft alternators and was hoping for some advice on where to start. I don't know if this has anything to do with it but I noticed my oil pressure gauge needle was not steady. All help appreciated. home wednesday ring then mick w Link to comment Share on other sites More sharing options...
Compulsion Posted October 7, 2013 Author Share Posted October 7, 2013 Thanks Mick. Wasn't sure when you got back. I will call later in the week. Link to comment Share on other sites More sharing options...
Jabiru Phil Posted October 7, 2013 Share Posted October 7, 2013 Thanks Phil. Nearly came over to Loxton today. Where would I go to get a new battery. Someone said the battery man on Hanson rd might have something. Got mine from a battery shop, sorry cant think of the name. They have a depot at Marion and Pooraka. I can make a phone call if you need to know. Phil Link to comment Share on other sites More sharing options...
Steve L Posted October 7, 2013 Share Posted October 7, 2013 Looks like your going to be busy Wednesday Mick, you have a Bulldog to ferry too Link to comment Share on other sites More sharing options...
Compulsion Posted October 8, 2013 Author Share Posted October 8, 2013 Charged the battery and it is holding charge. So now it must be the electrical system. No pressure Mick if you are busy I can wait. Steve I haven't seen the Bulldog fly lately. Great aircraft. Link to comment Share on other sites More sharing options...
Steve L Posted October 8, 2013 Share Posted October 8, 2013 Does the 170 have a volt gauge fitted because it sounds like its not charging John. I need to get the Bulldog to Murray Bridge to start my training in it, have nothing arranged with Mick yet except the sooner I get it there the sooner I qualify and the sooner I can take you upside down Link to comment Share on other sites More sharing options...
Compulsion Posted October 8, 2013 Author Share Posted October 8, 2013 No worries Steve. I am sure Mick would rather fly the Bulldog. Busy Saturday and the weather isn't looking great Sunday so no real hurry. Just need her ready for the Rawnsley Park trip in 3 weeks. Link to comment Share on other sites More sharing options...
Peter008 Posted October 8, 2013 Share Posted October 8, 2013 On the 170 look for a couple of things if it is not charging; 1. There are two wires coming from the stator down to the regulator. There are probably two joins in them with spade terminals. Look for a poor joint where it may be discoloured. The regulator connection is another hot joint point and it is often missed when looking as the plastic hides the poor connection. 2. Under the dash there is a relay on the LHS (if I recall correctly). Check if this relay energises when the key is turned on. I went on the Jab site and found the charging system wiring diagram when my 230 had issues and found the information easy to understand and simple to fault find. Cheers 1 Link to comment Share on other sites More sharing options...
Compulsion Posted October 8, 2013 Author Share Posted October 8, 2013 Thanks Peter008. Appreciate the help. Link to comment Share on other sites More sharing options...
geoffreywh Posted October 11, 2013 Share Posted October 11, 2013 have a look at the wires of the alternator, If they are "glossy" probably ok, If they look at all burnt or look as if they have been hot, it will probably be cactus ( technical term for kaput) Link to comment Share on other sites More sharing options...
Thirsty Posted October 11, 2013 Share Posted October 11, 2013 A lot of jabs have a fuse in one of the wires coming from the stator. If the battery is a little low and you rev the engine a bit after starting you can blow the fuse. If it has a fuse I'd put money on it being blown. If no fuse and the wiring looks ok and you think the battery is ok and the stator is putting out the appropriate voltages (sorry, lots of ands!) then the reg/rec will need checking. One last thing, just because the battery is holding a voltage under no load doesn't mean it's ok. Put a load on it and see what the voltage does. Hook up some 12v appliance to it and check. Link to comment Share on other sites More sharing options...
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