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8466 wrote: ↑Sun May 24, 2020 8:15 pmBefore I changed out the fuse it was powering the lighter which was shared with the landing light so the previous fuse was working fine except for the landing light.
I'm glad you got it fixed, but, that doesn't make sense. Fuses don't limit the current to the load. They conduct whatever the load demands until their rating is exceeded, then they blow. It's a one shot deal. They don't start working again when the load is reduced. Something else must be going on. If you're curious, put the old fuse back and see what happens.
Also, did you confirm that the lighter stops working when you remove the fuse? If it really is on the same circuit, then you have to confirm that the 20 amp fuse is sufficient protection for the lighter wiring (which may explain the smaller fuse.) Not the best setup, IMHO. I'd hate to have the landing light fuse blow while the landing light is on just because of a load on the lighter socket.
John, is that normal for the Cigar lighter and landing light to share the same fuse? From what I can see in the parts book ( 140A) the lighter and landing lights are separate fuses.
8474 wrote: ↑Mon May 25, 2020 7:51 am
is that normal for the Cigar lighter and landing light to share the same fuse?
There is no "normal". The lighter was originally unfused. There is an AD, 79-08-03, requiring that you either "reconnect the wire to the electrical bus by using an existing or newly installed circuit protection device that is properly rated to protect the wire gauge used for this circuit", or remove it completely.
Ahhh, so thats why the lighter was removed from my airplane. I have installed an STC'd receptical and ran it thru a CB, but only 5 amps as I use it for a USB charger.
8474 wrote: ↑Mon May 25, 2020 7:51 am
is that normal for the Cigar lighter and landing light to share the same fuse?
There is no "normal". The lighter was originally unfused. There is an AD, 79-08-03, requiring that you either "reconnect the wire to the electrical bus by using an existing or newly installed circuit protection device that is properly rated to protect the wire gauge used for this circuit", or remove it completely.
According to my ppwk on the 1946 140 it was normal.
8474 wrote: ↑Mon May 25, 2020 7:51 am
is that normal for the Cigar lighter and landing light to share the same fuse?
There is no "normal". The lighter was originally unfused. There is an AD, 79-08-03, requiring that you either "reconnect the wire to the electrical bus by using an existing or newly installed circuit protection device that is properly rated to protect the wire gauge used for this circuit", or remove it completely.
According to my ppwk on the 1946 140 it was normal.
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8466 wrote: ↑Sun May 24, 2020 8:15 pmBefore I changed out the fuse it was powering the lighter which was shared with the landing light so the previous fuse was working fine except for the landing light.
I'm glad you got it fixed, but, that doesn't make sense. Fuses don't limit the current to the load. They conduct whatever the load demands until their rating is exceeded, then they blow. It's a one shot deal. They don't start working again when the load is reduced. Something else must be going on. If you're curious, put the old fuse back and see what happens.
Also, did you confirm that the lighter stops working when you remove the fuse? If it really is on the same circuit, then you have to confirm that the 20 amp fuse is sufficient protection for the lighter wiring (which may explain the smaller fuse.) Not the best setup, IMHO. I'd hate to have the landing light fuse blow while the landing light is on just because of a load on the lighter socket.
Yes if I remove the fuse the lighter does not work.i do not know why the landing light works now after changing fuses but eventually I will convert to CB’s and when I do I will change the landing light and lighter to separate CB’s. I have currently a 25A fuse on that circuit.
6643 wrote: ↑Sun May 24, 2020 1:29 pm
Or, install a circuit breaker. (Or at least a newer fuse holder.)
Good advice....I replaced all the old fuse holders with CB's
How much skill do you need to changeover? Do I need a A&P? I have some technical knowledge of electrical.
It is not necessarily a question of Skill as who can approve for return to service.
Meaning who can sign off the Maintenance Logbook showing the work performed.
If you look in the FAR's Pert 43 Appendix A under "Preventive Maintenance" you will find a list of items that a a pilot may perform and sign off.
If it is not on the list you will need an A&P to do the sign off.
If you know an A&P that will work with you to look over your should as you do the work, then you could do the work but he would need to do the logbook sign off.
