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Electrical Issue

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poasttown(at)yahoo.com
Guest

Posted: Thu Jul 06, 2017 10:19 am Post subject: Electrical Issue

I would like to throw an issue to the group to see If there are any suggestions.

This involves a Kitfox IV with Jabiru 2200 .

Before departure last week I pushed the "push to talk" button to announce my intentions and noticed my electrical oil pressure gauge needle went down.  The engine continued to run fine.  When I released the PTT button the gauge indicated normal again.  If fact any time I turned on a electrical device; strobes or transponder, the oil pressure needle went down.



I have checked for loose wires, chafed wires, loose connections and found nothing.  I replace the oil pressure gauge and the problem persisted.  



I am in no way an electrical expert and not sure if I even understand the problem let alone solve the problem.  I didn't just change the oil pressure gauge as a shot in the dark hoping for a fix, there were a few other things which didn't seem right with the gauge. However, I really don't want to begin buying and replacing parts just to see if it fixes the problem. This can get expensive.

Any comment are welcome.

Mike

1996 Kitfox IV, Jabiru 2200



Sent from my iPad

Guy Buchanan

Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA

Posted: Thu Jul 06, 2017 1:07 pm Post subject: Electrical Issue

Ima gonna say bad ground, somewhere. The oil pressure is voltage based 

so any time an additional electrical load causes a voltage variation to 

the sender it will change the signal. If your's is a single wire sender 

then the sender's trying to ground through it's attachment, which can 

frequently be a problem. I changed my single wire sender to a double 

wire with dedicated ground for that reason. Otherwise there might be a 

problem with your engine ground strap.



Guy Buchanan

Ramona, CA

Kitfox IV-1200 / 912-S / Warp 3cs / 600 hrs

Glider pilot, too



On 7/6/2017 11:19 AM, Mike Chaney wrote:

 	  Quote: 	
		   



 I would like to throw an issue to the group to see If there are any suggestions.

 This involves a Kitfox IV with Jabiru 2200 .

 Before departure last week I pushed the "push to talk" button to announce my intentions and noticed my electrical oil pressure gauge needle went down.  The engine continued to run fine.  When I released the PTT button the gauge indicated normal again.  If fact any time I turned on a electrical device; strobes or transponder, the oil pressure needle went down.



 I have checked for loose wires, chafed wires, loose connections and found nothing.  I replace the oil pressure gauge and the problem persisted.



 I am in no way an electrical expert and not sure if I even understand the problem let alone solve the problem.  I didn't just change the oil pressure gauge as a shot in the dark hoping for a fix, there were a few other things which didn't seem right with the gauge. However, I really don't want to begin buying and replacing parts just to see if it fixes the problem. This can get expensive.

 Any comment are welcome.

 Mike

 1996 Kitfox IV, Jabiru 2200



 Sent from my iPad

_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too.

michaelgibbs(at)cox.net
Guest

Posted: Thu Jul 06, 2017 2:51 pm Post subject: Electrical Issue

I agree with Guy. I think a lot of times builders decide that using the fuselage weldment as a ground is the easy solution but, in my experience, it seldom provides reliable performance. My starter solenoid was originally wired that way and it seemed like everything was good but, after a while, I realized it was only working intermittently. Running a wire from the solenoid to a good ground fixed the problem.

Mike G.

Phoenix, AZ

Kitfox IV-1200 Speedster/Series 7

 	  Quote: 	
		   On Jul 6, 2017, at 2:06 PM, Guy Buchanan <gebuchanan(at)cox.net> wrote:

 Ima gonna say bad ground, somewhere. The oil pressure is voltage based so any time an additional electrical load causes a voltage variation to the sender it will change the signal. If your's is a single wire sender then the sender's trying to ground through it's attachment, which can frequently be a problem. I changed my single wire sender to a double wire with dedicated ground for that reason. Otherwise there might be a problem with your engine ground strap.

 Guy Buchanan

 Ramona, CA

 Kitfox IV-1200 / 912-S / Warp 3cs / 600 hrs

 Glider pilot, too

> On 7/6/2017 11:19 AM, Mike Chaney wrote:

> 

> 

> I would like to throw an issue to the group to see If there are any suggestions.

> This involves a Kitfox IV with Jabiru 2200 .

> Before departure last week I pushed the "push to talk" button to announce my intentions and noticed my electrical oil pressure gauge needle went down.  The engine continued to run fine.  When I released the PTT button the gauge indicated normal again.  If fact any time I turned on a electrical device; strobes or transponder, the oil pressure needle went down.

> 

> I have checked for loose wires, chafed wires, loose connections and found nothing.  I replace the oil pressure gauge and the problem persisted.

> 

> I am in no way an electrical expert and not sure if I even understand the problem let alone solve the problem.  I didn't just change the oil pressure gauge as a shot in the dark hoping for a fix, there were a few other things which didn't seem right with the gauge. However, I really don't want to begin buying and replacing parts just to see if it fixes the problem. This can get expensive.

> Any comment are welcome.

> Mike

> 1996 Kitfox IV, Jabiru 2200

>

poasttown(at)yahoo.com
Guest

Posted: Fri Jul 07, 2017 8:18 am Post subject: Electrical Issue

Thanks for the comments.  My battery is grounded to the engine and I cleaned the connection, problem remained.

My ground bus bar is grounded to the frame which from what you guys are saying could be a problem. To check this I will connect this ground in a better location.

I did notice that there is a small amount of current registering on the radio side of my toggle switch when it is switched off.  Is there some residual power in the radio? I even disconnected the battery neg. terminal and it was still there.

Mike

Sent from my iPad

 	  Quote: 	
		   On Jul 6, 2017, at 6:50 PM, Michael Gibbs <michaelgibbs(at)cox.net> wrote:

 I agree with Guy. I think a lot of times builders decide that using the fuselage weldment as a ground is the easy solution but, in my experience, it seldom provides reliable performance. My starter solenoid was originally wired that way and it seemed like everything was good but, after a while, I realized it was only working intermittently. Running a wire from the solenoid to a good ground fixed the problem.

 Mike G.

 Phoenix, AZ

 Kitfox IV-1200 Speedster/Series 7

> On Jul 6, 2017, at 2:06 PM, Guy Buchanan <gebuchanan(at)cox.net> wrote:

> 

> 

> 

> Ima gonna say bad ground, somewhere. The oil pressure is voltage based so any time an additional electrical load causes a voltage variation to the sender it will change the signal. If your's is a single wire sender then the sender's trying to ground through it's attachment, which can frequently be a problem. I changed my single wire sender to a double wire with dedicated ground for that reason. Otherwise there might be a problem with your engine ground strap.

> 

> Guy Buchanan

> Ramona, CA

> Kitfox IV-1200 / 912-S / Warp 3cs / 600 hrs

> Glider pilot, too

> 

> 

> 

>> On 7/6/2017 11:19 AM, Mike Chaney wrote:

>> 

>> 

>> I would like to throw an issue to the group to see If there are any suggestions.

>> This involves a Kitfox IV with Jabiru 2200 .

>> Before departure last week I pushed the "push to talk" button to announce my intentions and noticed my electrical oil pressure gauge needle went down.  The engine continued to run fine.  When I released the PTT button the gauge indicated normal again.  If fact any time I turned on a electrical device; strobes or transponder, the oil pressure needle went down.

>> 

>> I have checked for loose wires, chafed wires, loose connections and found nothing.  I replace the oil pressure gauge and the problem persisted.

>> 

>> I am in no way an electrical expert and not sure if I even understand the problem let alone solve the problem.  I didn't just change the oil pressure gauge as a shot in the dark hoping for a fix, there were a few other things which didn't seem right with the gauge. However, I really don't want to begin buying and replacing parts just to see if it fixes the problem. This can get expensive.

>> Any comment are welcome.

>> Mike

>> 1996 Kitfox IV, Jabiru 2200

>>

Guy Buchanan

Joined: 16 Jul 2006
Posts: 1204
Location: Ramona, CA

Posted: Fri Jul 07, 2017 12:48 pm Post subject: Electrical Issue

Make sure you check the oil pressure sender ground. As to current with 

no battery, it's possible with a slowly discharging capacitor, but 

unless there's another battery in the system the current should 

eventually reach zero. Also, I have had ground straps go bad, but the 

first sign is difficulty starting, which I don't think you're having.



Guy Buchanan

Ramona, CA

Kitfox IV-1200 / 912-S / Warp 3cs / 600 hrs

Glider pilot, too



On 7/7/2017 9:18 AM, Mike Chaney wrote:

 	  Quote: 	
		   



 Thanks for the comments.  My battery is grounded to the engine and I cleaned the connection, problem remained.

 My ground bus bar is grounded to the frame which from what you guys are saying could be a problem. To check this I will connect this ground in a better location.

 I did notice that there is a small amount of current registering on the radio side of my toggle switch when it is switched off.  Is there some residual power in the radio? I even disconnected the battery neg. terminal and it was still there.

 Mike



 Sent from my iPad



> On Jul 6, 2017, at 6:50 PM, Michael Gibbs <michaelgibbs(at)cox.net> wrote:

>

> 

>

> I agree with Guy. I think a lot of times builders decide that using the fuselage weldment as a ground is the easy solution but, in my experience, it seldom provides reliable performance. My starter solenoid was originally wired that way and it seemed like everything was good but, after a while, I realized it was only working intermittently. Running a wire from the solenoid to a good ground fixed the problem.

>

> Mike G.

> Phoenix, AZ

> Kitfox IV-1200 Speedster/Series 7

>

>> On Jul 6, 2017, at 2:06 PM, Guy Buchanan <gebuchanan(at)cox.net> wrote:

>>

>> 

>>

>> Ima gonna say bad ground, somewhere. The oil pressure is voltage based so any time an additional electrical load causes a voltage variation to the sender it will change the signal. If your's is a single wire sender then the sender's trying to ground through it's attachment, which can frequently be a problem. I changed my single wire sender to a double wire with dedicated ground for that reason. Otherwise there might be a problem with your engine ground strap.

>>

>> Guy Buchanan

>> Ramona, CA

>> Kitfox IV-1200 / 912-S / Warp 3cs / 600 hrs

>> Glider pilot, too

>>

>>

>>

>>> On 7/6/2017 11:19 AM, Mike Chaney wrote:

>>> 

>>>

>>> I would like to throw an issue to the group to see If there are any suggestions.

>>> This involves a Kitfox IV with Jabiru 2200 .

>>> Before departure last week I pushed the "push to talk" button to announce my intentions and noticed my electrical oil pressure gauge needle went down.  The engine continued to run fine.  When I released the PTT button the gauge indicated normal again.  If fact any time I turned on a electrical device; strobes or transponder, the oil pressure needle went down.

>>>

>>> I have checked for loose wires, chafed wires, loose connections and found nothing.  I replace the oil pressure gauge and the problem persisted.

>>>

>>> I am in no way an electrical expert and not sure if I even understand the problem let alone solve the problem.  I didn't just change the oil pressure gauge as a shot in the dark hoping for a fix, there were a few other things which didn't seem right with the gauge. However, I really don't want to begin buying and replacing parts just to see if it fixes the problem. This can get expensive.

>>> Any comment are welcome.

>>> Mike

>>> 1996 Kitfox IV, Jabiru 2200

>>>

>

>

_________________
Guy Buchanan
Deceased K-IV 1200
A glider pilot too.

poasttown(at)yahoo.com
Guest

Posted: Sun Jul 09, 2017 4:41 am Post subject: Electrical Issue

Thanks for all the comments.  I installed another ground wire from the bus bar, this didn't help the situation.  I will look at a few other solutions mentioned as well.  What I find interesting is the degree to which the push to talk button causes the oil pressure needle to move.  My plane is pretty basic and I don't have a lot of electronics installed. I suppose I could begin disconnecting items one by one but not sure this would get me any closer to a solution.  



I'm not sure how big a problem this is.  It could have been an issue for some time.  It's really noticeable when I use the PTT button which is when I'm looking outside for traffic and not at my panel.

Mike



Sent from my iPad



 	  Quote: 	
		   On Jul 7, 2017, at 4:48 PM, Guy Buchanan <gebuchanan(at)cox.net> wrote:

 

 

 

 Make sure you check the oil pressure sender ground. As to current with no battery, it's possible with a slowly discharging capacitor, but unless there's another battery in the system the current should eventually reach zero. Also, I have had ground straps go bad, but the first sign is difficulty starting, which I don't think you're having.

 

 Guy Buchanan

 Ramona, CA

 Kitfox IV-1200 / 912-S / Warp 3cs / 600 hrs

 Glider pilot, too

 

 

 

> On 7/7/2017 9:18 AM, Mike Chaney wrote:

> 

> 

> Thanks for the comments.  My battery is grounded to the engine and I cleaned the connection, problem remained.

> My ground bus bar is grounded to the frame which from what you guys are saying could be a problem. To check this I will connect this ground in a better location.

> I did notice that there is a small amount of current registering on the radio side of my toggle switch when it is switched off.  Is there some residual power in the radio? I even disconnected the battery neg. terminal and it was still there.

> Mike

> 

> Sent from my iPad

> 

>> On Jul 6, 2017, at 6:50 PM, Michael Gibbs <michaelgibbs(at)cox.net> wrote:

>> 

>> 

>> 

>> I agree with Guy. I think a lot of times builders decide that using the fuselage weldment as a ground is the easy solution but, in my experience, it seldom provides reliable performance. My starter solenoid was originally wired that way and it seemed like everything was good but, after a while, I realized it was only working intermittently. Running a wire from the solenoid to a good ground fixed the problem.

>> 

>> Mike G.

>> Phoenix, AZ

>> Kitfox IV-1200 Speedster/Series 7

>> 

>>> On Jul 6, 2017, at 2:06 PM, Guy Buchanan <gebuchanan(at)cox.net> wrote:

>>> 

>>> 

>>> 

>>> Ima gonna say bad ground, somewhere. The oil pressure is voltage based so any time an additional electrical load causes a voltage variation to the sender it will change the signal. If your's is a single wire sender then the sender's trying to ground through it's attachment, which can frequently be a problem. I changed my single wire sender to a double wire with dedicated ground for that reason. Otherwise there might be a problem with your engine ground strap.

>>> 

>>> Guy Buchanan

>>> Ramona, CA

>>> Kitfox IV-1200 / 912-S / Warp 3cs / 600 hrs

>>> Glider pilot, too

>>> 

>>> 

>>> 

>>>> On 7/6/2017 11:19 AM, Mike Chaney wrote:

>>>> 

>>>> 

>>>> I would like to throw an issue to the group to see If there are any suggestions.

>>>> This involves a Kitfox IV with Jabiru 2200 .

>>>> Before departure last week I pushed the "push to talk" button to announce my intentions and noticed my electrical oil pressure gauge needle went down.  The engine continued to run fine.  When I released the PTT button the gauge indicated normal again.  If fact any time I turned on a electrical device; strobes or transponder, the oil pressure needle went down.

>>>> 

>>>> I have checked for loose wires, chafed wires, loose connections and found nothing.  I replace the oil pressure gauge and the problem persisted.

>>>> 

>>>> I am in no way an electrical expert and not sure if I even understand the problem let alone solve the problem.  I didn't just change the oil pressure gauge as a shot in the dark hoping for a fix, there were a few other things which didn't seem right with the gauge. However, I really don't want to begin buying and replacing parts just to see if it fixes the problem. This can get expensive.

>>>> Any comment are welcome.

>>>> Mike

>>>> 1996 Kitfox IV, Jabiru 2200

>>>> 

>> 

>> 

>> 

>> 

> 

> 

> 

>

Float Flyr

Joined: 19 Jul 2006
Posts: 2704
Location: Campbellton, Newfoundland

Posted: Sun Jul 09, 2017 5:28 pm Post subject: Electrical Issue

I go along with the rest of the crowd.  The problem sounds like a bad ground.  Since your battery is grounded to the engine the sender should get full clean voltage.  However your instrument may not...   First thing I would do is put a nice healthy grounding strap from the engine to the frame of the plane.



If your radio is a digital unit with memories on it that may be the little leak you are noticing.  There is a certain amount of current used to keep memories in the radio intact.



Noel



--

_________________
Noel Loveys
Kitfox III-A
Aerocet 1100 Floats

mikeperkins

Joined: 22 May 2007
Posts: 123

Posted: Mon Jul 10, 2017 8:44 am Post subject: Re: Electrical Issue

Try running the oil pressure's power input wire directly to the battery, just as a test. There might be a voltage drop in the electrical bus when you turn on loads.

_________________
Mike Perkins
Havana, Illinois
Model I, 532, B gearbox, GSC prop

MDKitfox(at)aol.com
Guest

Posted: Mon Jul 10, 2017 8:59 am Post subject: Electrical Issue

Mike,

While I didn’t have the problem with my Kitfox, I did have it on my RV-7A.  My problem was with oil temp, but the same logic is applicable.  I changed the sensor and still had the problem.  Checked the grounds and alternator, still couldn’t solve it.  Added a new ground strap on the sensor directly to the engine ground.  Nothing worked.  However I noticed with the alternator off, the sensor worked perfectly.  Weird.  A friend suggested a long charging wire for the battery, from my hangar to the airplane, while in flight, but a thousand mile wire didn’t seem to be the answer:-)

Finally, with all the troubleshooting info in hand, AFS recommended a 2 wire sensor.  Not only did I do that, but I wired the sensor ground directly to the avionics bus on the firewall.  Even with no resistance between the airframe and engine, I’m told the slight voltage drop between the engine and airframe was enough to screw up the sensor.  I didn’t understand this, but it solved the problem. 

Lesson Learned:   It’s always the darn ground - even when it checks out good it isn’t.  Go figure.

Good luck!  Hope this helped.

Rick Weiss

Series V, Rotax 912ULS

 	  Quote: 	
		   On Jul 6, 2017, at 6:50 PM, Michael Gibbs <michaelgibbs(at)cox.net> wrote:

 I agree with Guy. I think a lot of times builders decide that using the fuselage weldment as a ground is the easy solution but, in my experience, it seldom provides reliable performance. My starter solenoid was originally wired that way and it seemed like everything was good but, after a while, I realized it was only working intermittently. Running a wire from the solenoid to a good ground fixed the problem.

 Mike G.

 Phoenix, AZ

 Kitfox IV-1200 Speedster/Series 7

> On Jul 6, 2017, at 2:06 PM, Guy Buchanan <gebuchanan(at)cox.net> wrote:

> 

> 

> 

> Ima gonna say bad ground, somewhere. The oil pressure is voltage based so any time an additional electrical load causes a voltage variation to the sender it will change the signal. If your's is a single wire sender then the sender's trying to ground through it's attachment, which can frequently be a problem. I changed my single wire sender to a double wire with dedicated ground for that reason. Otherwise there might be a problem with your engine ground strap.

> 

> Guy Buchanan

> Ramona, CA

> Kitfox IV-1200 / 912-S / Warp 3cs / 600 hrs

> Glider pilot, too

> 

> 

> 

>> On 7/6/2017 11:19 AM, Mike Chaney wrote:

>> 

>> 

>> I would like to throw an issue to the group to see If there are any suggestions.

>> This involves a Kitfox IV with Jabiru 2200 .

>> Before departure last week I pushed the "push to talk" button to announce my intentions and noticed my electrical oil pressure gauge needle went down.  The engine continued to run fine.  When I released the PTT button the gauge indicated normal again.  If fact any time I turned on a electrical device; strobes or transponder, the oil pressure needle went down.

>> 

>> I have checked for loose wires, chafed wires, loose connections and found nothing.  I replace the oil pressure gauge and the problem persisted.

>> 

>> I am in no way an electrical expert and not sure if I even understand the problem let alone solve the problem.  I didn't just change the oil pressure gauge as a shot in the dark hoping for a fix, there were a few other things which didn't seem right with the gauge. However, I really don't want to begin buying and replacing parts just to see if it fixes the problem. This can get expensive.

>> Any comment are welcome.

>> Mike

>> 1996 Kitfox IV, Jabiru 2200

>>

poasttown(at)yahoo.com
Guest

Posted: Tue Jul 11, 2017 5:52 am Post subject: Electrical Issue

Mike

Thanks for the suggestion.  I did run a wire directly from the pos wire of the gauge to the pos terminal of the battery.  The same problem remained.  However, after reconnecting the pos wire to their original location, I then run a wire from the ground wire of the gauge to the main ground on the engine and the problem went away.  



I think this tells me that my ground system isn't grounding as well as it should, I think.  I previously run the same grounding wire from the engine to the  neg bus bar and it didn't eliminate the problem. This make me scratch my head.  I'm going to repeat the grounding of the bus bar to double check.

Mike Chaney



Sent from my iPhone



 	  Quote: 	
		   On Jul 10, 2017, at 12:44 PM, mikeperkins <flybyewire(at)gmail.com> wrote:

 

 

 

 Try running the oil pressure's power input wire directly to the battery, just as a test. There might be a voltage drop in the electrical bus when you turn on loads.

 

 --------

 Mike Perkins

 Havana, Illinois 

 Model I, 532, B gearbox, GSC prop

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=470862#470862

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