T

tullow

Member
Hello to all,
I've recently started to have an unusual problem with my basic Vans fuel guages.
When I first switch on the master switch my fuel guages indicate normally,however after engine start with the alternator on line, either one or both guages indicate zero. As I use full tanks minus fuel used on the AFP30 for my fuel management, it's not a real safety issue but it bothers me nonetheless.
I have a Denso 30A internally regulated alternator which I always switch on before engine start and only switch off after engine shutdown.
Anybody got any idea what may be happening here.?
Thanks in advance

Mike

RV7
 
Probably a bad connection

Bit of diagnostic elimination needed here.

First I would check all the connections on the back of the guages especially the earth.

If that does not sort the problem the connections on the bus, circuit breaker.

Next the resistance on the tank senders which can be done by removing the wire off the back of the guage. I cant remember the figures of the top of my head but if you search the forums I know they are listed somewhere because I have seen them.
 
Thanks for your advice Steve, I'll go through your step by step trouble-shooting during the week and see what I may find. I've already checked the connections on the back of the guages with no joy. I was somehow hoping that this was a well known problem with Vans guages ( like the ammeter/mic keying problem)
Thanks again

Mike
 
My thoughts would be that the problem is a loose connection somewhere which becomes evident after engine start due vibration - nothing to do with alternator power vs battery.
 
Well I only got back to the airport last Saturday and after a full checkout for loose connections ( all,that is ,except those on the fuel senders beneath the root fairings ) I flew twice for about 40 minutes each time, lots of wind and turbulence and of course the gauges indicated perfectly throughout !!!. The mystery deepens !. Sticking senders ? , I somehow don't think so.

Mike
 
I had the same issue with one of my gauges after 5 or so years.
Replaced Gauge.

Problem solved
 
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