TheSamba.com :: View topic - 63 - 65 US spec turn signal emergency flasher tester

Mon May 12, 2025 9:29 pm

Finally getting back to this. BarryL, the 'coil' light and 'brake switch' push button are an attempt to do just that; not sure if it an exact substitute, tho.

The Kind Mr. Dorr had requested a schematic, and here is my enfeebled attempt. You would guess I am either 4 or 104 years old based on this sketch...

Power comes from battery, and a switch either feeds 12v straight to circuit breaker and terminal block 'fuses,' or first sends to converter to 6v and then to circuit breakers.

All of the rest of the circuits are as depicted in '63 US w/ emergency flashers' schematics on thesamba. As per stock, the 'always hot fuse' part of terminal has a wire to the + terminal on t/s can, and to a selector switch, which allows the indicator bulb's "ground" terminal to be connected to 'hot' fuse, or to a 'ign on' power source depending on which wiring scheme tested. The 'hot' terminal on the indicator bulb goes to k on t/s can.

I didn't put grounds on this version to keep it somewhat legible, but will make one with them in case there is a backfeed somewhere important.

My main two questions: why, when using a non-K t/s relay, does it all work as advertised??? Yes, a 49a relay makes the indicator light flash opposite to t/s bulbs, but nothing ever gives me the main issue with these buses, which is the indicator light staying lit at wrong time. Nor do I get the 'bulbs light/don't flash' some people get. Second question is whether pushing a 'brake' switch and having it power a light is the same as that quirk of on-off-on w coil circuit. It should be, as pushing the brake is sending backfeed power to the coil, but maybe not.Not a deal breaker for the tester, but it would be nice to replicate all issues with these buses.

The Businabox is just a fun toy-cum-relay-tester if it can't mimic real-world issues to troubleshoot other buses. I was told today I obviously had too much time on my hands! True, but I was able to help them with a bus needing this circuit worked on, so not a total waste of time to learn all this.

Tue May 13, 2025 11:58 am

Absolutely fasinating! You've got electrical skills Sir!

Now you'll have to go on a nationwide tour visiting all of us out here who have little piles of relays and have always wondered if they function properly or not. We don't have the heart to toss any of the "dubious" relays out! You could earn lodging, gas money beers and our eternal gratitude! LOL! A very cool invention!

Bill Bowman

Tue May 13, 2025 12:13 pm

I was thinking of going to Woodburn with my box, dressed up in my VW overalls and a top hat... going up to bus owners

"Evnin' Guvnah - need yer flashes tested t'day?"

Wed May 14, 2025 5:31 pm

Do it Craig! Also tried the emergency flasher and brake thing on my Dec. 63. Probably not the best thing to try for an extended period…The flashers stopped flashing, the oil and gen lights lit up solid on, and the fuel gauge needle started dancing!!!

Wed May 14, 2025 7:05 pm

ok, so that's two buses with identical "bad" behavior when hazards on and brake stomped... so either we have our buses wired correctly, or we both hve the same screwup somewhere! :)

Do you have a tach? What does it do? My new aftermarket one does not like it and gets jumpy. Need to hook up an older type to test it as well.

Wed May 14, 2025 7:19 pm

70bus wrote: ok, so that's two buses with identical "bad" behavior when hazards on and brake stomped... so either we have our buses wired correctly, or we both hve the same screwup somewhere! :)

With turn signal itself the brake is turned off to the taillight that is supposed to suddenly show flashing turn signal. With E-flasher engaged there is no switch shut off to keep brake light turned off. So one gets a back feed to other electricals.

Wed May 14, 2025 7:26 pm

No need for a tach have the governor set at 4200rpm.

Thu May 15, 2025 6:19 pm

Can you show the Bus-In-A-Box do the off-on coil light?