View Full Version : PA18 A Master switch

05-25-2004, 08:08 AM
I have a 1957 PA18 A based in Ireland.....i note my master switch works in alternate mode and not in norm. I have checked the 30amp fuses at the rear....reckon its the actual toggle switch....was looking at spruce aviation catalog for a new switch....is there a standard switch to buy I should know of?

05-25-2004, 12:53 PM
Make sure that the fuse block is good, I had mine get loose and lose continuity, check it out before changing the switch. Dave

Steve Pierce
05-25-2004, 02:55 PM
Ditto what Dave said. Those fuse blocks are hell on earth for sure. I have had numerous problems with them. I have replaced a few with a circuit breaker.

05-25-2004, 08:55 PM
For your doityourselferkindaownerpilot I heard you can find a modern identical replacement from granger. The dual fuse block that is. I here there much better and should outlast the plane.

05-26-2004, 11:31 AM
forgive my ignorance but what should I be looking for re the fuse block. mine is old but looks in tact....i have a man sending me over a switch ...hopefuly that will sort the prob.

Steve Pierce
05-26-2004, 12:08 PM
I would check voltage on each side of both fuse holders. Then do the same while wiggling the wires. I have seen them corroded and also seen the fuse holder clips get weak and not conduct.

05-26-2004, 03:13 PM
In addition to what Master Steve said check the rivets that hold the fuse clips. I think thats what failed on mine. This same failer can creat all kinds of radio interference. A quick check for the fuse block is to make up an alegator clip with # 12 standed and jump the wire connections on the bad fuse side. Don't jump the fuse that won't tell you anything. jump both wires for that matter to see which side it is.

05-26-2004, 07:11 PM

The original part no. for this type of switch is AN3023-1B. If you need I can e-mail you a pdf file with the electrical schematic.

If you are rebuilding your plane I'd strongly recommend to update to a more modern system with circuit breakers, master solenoid and solenoid for the landing lights.

Good luck

05-27-2004, 04:02 AM
thanks guys....funny you say about interference on the radio.....just have ordered a fuse block off univair, relevant wiring and fuses. the electrical system in the cub is not rocket science so hopefullly between the fuse block and a switch we wil sorted. thanks again guys.

SuperCub MD
05-27-2004, 03:53 PM
You might want to just clean the switch, fuseblock and connections with contact cleaner. 90+% of the time this works, and will get things working and the plane back in the air till your new parts come.

05-28-2004, 01:48 AM
guys...problem sorted. having said that the parts what are coming will be fitted as the original parts have seen better days. stripped the fuse box yesterday on your advise and went through every thing with a continuity phase tester....the fuses all looked fine but one fuse would test properly even though it looked fine....this was the gremlin. having said that i need a new fuse block and my master switch is corroded so i have parts coming to replace. so not a worthless exercise and i thank all of you for sharing your knowledge.