Turn signal troubleshooting

RallyBus · 03-24-2021, 06:48 AM

Looking for some insight on where to go from here in finding a short. 2000 BB TC/2000 FE.

Was taking it on a short trip (30 minutes) and they went out halfway there.

Left turn signal works fine and can hear flasher clicking but when right turn signal or hazards are engaged it pops the fuse instantly before anything lights up or clicks.

I have checked all the easy stuff, removed lenses to check wires and bulbs, removed steering wheel to check switch and traced what I can for wires in the dash and electrical compartment and found no issues.

How does power flow from the switch in the column? To the flasher, fuse box and out to the bulb, I'm assuming?
Can the column switch short out internally? It looks fine but the right signal didn't always self cancel.

Easier to try and chase or just run another wire?

Any wiring diagrams out there?

CHEESE_WAGON · 03-24-2021, 06:53 AM

Switch is most common, and easiest to eliminate. Most get a lot more wear-and-tear than you might think.

rffffffff · 03-24-2021, 08:09 AM

Quote:

Originally Posted by CHEESE_WAGON

Most get a lot more wear-and-tear than you might think.

Not when I drive!

ewo1 · 03-24-2021, 08:57 AM

Quote:

Originally Posted by RallyBus

Looking for some insight on where to go from here in finding a short. 2000 BB TC/2000 FE.

Was taking it on a short trip (30 minutes) and they went out halfway there.

Left turn signal works fine and can hear flasher clicking but when right turn signal or hazards are engaged it pops the fuse instantly before anything lights up or clicks.

I have checked all the easy stuff, removed lenses to check wires and bulbs, removed steering wheel to check switch and traced what I can for wires in the dash and electrical compartment and found no issues.

How does power flow from the switch in the column? To the flasher, fuse box and out to the bulb, I'm assuming?
Can the column switch short out internally? It looks fine but the right signal didn't always self cancel.

Easier to try and chase or just run another wire?

Any wiring diagrams out there?

Pull out all the bulbs on the right side, replace the fuse...turn on right signal...does the fuse pop without the bulbs?

If so...

Pull fuse and using the continuity (ohms) function on the meter, engine off but blinker switch up like your were signaling a right turn....

on both legs within the fuse holder check for a direct short to ground,

Red lead on the fuse pin, black lead to chassis.
do this on both pins in the fuse holder. What your doing is trying to determine is on what side of the fuse the hard short to ground might be.

the reason for pulling the bulbs is that the meter will pick up slight resistance from the bulb winding. On a dead short the meter should beep for continuity and read zero on the screen.

Mountain Gnome · 03-24-2021, 10:23 AM

You can get the wiring diagram at this page:

https://www.centralstatesbus.com/2003_bbaa/a3mtocs

It says for an All American, but I believe the chassis is wired the same or similar.

also, see the Bluebird Vantage Portal:

https://vantage.blue-bird.com/Portal/Vantage-Home.aspx

They didn't have the wiring info for my bus, so I use one from a later model All American

CHEESE_WAGON · 03-24-2021, 01:15 PM

Quote:

Originally Posted by rffffffff

Not when I drive!

1) You weren't the one driving it before you bought it.

2) You should get in the habit with something this big. Very dangerous attitude to have even with a smaller vehicle. It will get you into trouble quick with a bus. These things can kill someone without even trying.

KlingonFiero · 03-25-2021, 01:28 PM

Getting back on topic...

I’d look at the switch itself first.
It sounds like it is worn out. They way they are made, the contact part could be touching the steering wheel housing.

This can be a bit of fun to check, as you will need to pull the steering wheel in most cases to check the physical functioning of the switch. It’s a complicated looking plastic ring with a cam or two. This switch is placed over the shaft before the steering wheel is attached.

Also, if it doesn’t self cancel, that’s pretty indicative of a worn out switch. They rely on a plastic cam and they wear out after a while.

If the switch itself tests good, you probably have a dead short somewhere in the Right Signal circuit.

Get a voltmeter and start testing to ground along the hot wire coming from the switch.
Make sure there isn’t Power coming into that circuit when you start testing to ground though!

RallyBus · 03-26-2021, 07:52 AM

ewo1

Got a multi meter and did some testing last night until it got too dark and the mosquitos were trying to carry me away.

Did as you said and I got 0 or OL on the power side, side that receives power from the bus bar in the electrical cabinet but got 12.4 ish ohms on the other. Also the fuse did blow with the bulbs out.

I then disconnected the plug for the harness going to the back, testing rearward I got 0 or OL and going forward I got 12.4 ish again. Assuming this means it's not grounding out in that part of the harness all the way to the tail light.

Going forward from there the wires are still tucked nicely in the harness and head under the dash making it real tough to follow them.

I did remove the steering wheel to get to the switch and check those wires, everything looks good. The wire colors don't match the schematic. Replaced already? I did find the issue for my intermittent not cancelling, the screws were loose allowing too much play in it.

Any way to test the signal switch and or the hazard switch? Seems to me unplugging it won't work but could be wrong. Don't want to just replace and see but is looking like it may be the problem.

Will pull the flasher/relay panel tonight and go from there.

Thanks everyone for the help so far!

KlingonFiero · 03-26-2021, 08:23 AM

Glad it was just loose screws. Must have known it was going to a Skoolie!

In regards to testing the switches, should be straight forward open/close positions.

Unplug the switch and back probe looking for continuity when you activate the switch.

If you still have the steering wheel off, you can visually trace the wires and see what is supposed to connect.

The wire colors of the wire on the switch side are usually not relevant to anything. Up to the manufacturer of the switch itself.

ewo1 · 03-26-2021, 10:16 AM

Quote:

Originally Posted by RallyBus

ewo1

Got a multi meter and did some testing last night until it got too dark and the mosquitos were trying to carry me away.

Did as you said and I got 0 or OL on the power side, side that receives power from the bus bar in the electrical cabinet but got 12.4 ish ohms on the other. Also the fuse did blow with the bulbs out.

I then disconnected the plug for the harness going to the back, testing rearward I got 0 or OL and going forward I got 12.4 ish again. Assuming this means it's not grounding out in that part of the harness all the way to the tail light.

Going forward from there the wires are still tucked nicely in the harness and head under the dash making it real tough to follow them.

I did remove the steering wheel to get to the switch and check those wires, everything looks good. The wire colors don't match the schematic. Replaced already? I did find the issue for my intermittent not cancelling, the screws were loose allowing too much play in it.

Any way to test the signal switch and or the hazard switch? Seems to me unplugging it won't work but could be wrong. Don't want to just replace and see but is looking like it may be the problem.

Will pull the flasher/relay panel tonight and go from there.

Thanks everyone for the help so far!

I hope you pulled the fuse out first before testing, that is required!

I got 0 or OL on the power side, side that receives power from the bus bar in the electrical cabinet but got 12.4 ish ohms on the other. Also the fuse did blow with the bulbs out.
When testing continuty (sorts/opens), when you touch to the meter leads together the meter should read ZERO. On the power side, if the fuse was in that could give you a false reading or it could also be a normal reading. Depends on the "feed" side of the wiring but essentially there must be NO voltage on the feed side in order to test continuity.

Rwnielsen · 03-26-2021, 10:53 AM

Typical turn signal switch is a SPDT, single pole double throw. It directs power to either left, right or off. Emergency flasher switches typically tie all 3 together. There's nothing too complex.

RallyBus · 03-26-2021, 01:37 PM

Yes, fuse out and key off.

ewo1 · 03-26-2021, 05:09 PM

Quote:

Originally Posted by RallyBus

then disconnected the plug for the harness going to the back, testing rearward I got 0 or OL and going forward I got 12.4 ish again..

Ok, let's try it like this...
From the fuse out to the bulbs we shall call the field side.
From the fuse to the battery (power) we will call the feed side.

So looking out to the field with NO bulbs you said you got 12.4 ish ohms
This indicates to me that the meter is seeing some kind of load on it. Could be a bulb or it could be a short to ground or crossed with another wire. . On the fleld side with no load there should be no continuity at all...You should read infinity with the meter!

With the meter on continuity, fuse out, go to where on of the bulbs were, put one lead on a clean piece of metal/chassis and the other to the positive wire of the bulb socket.
Again you should read nothing, infinity. If you get any kind of reading there is your problem.

I have seen bulb holder go bad and create an internal short so a visual inspection of the bulb holder on every bulb removed should be inspected and or cleaned.

also perform the same test with the blinker relay removed, you are looking for nice clean lines.
Anything that goes to zero, when measuring continuity is a problem!

Rwnielsen · 03-26-2021, 09:11 PM

Don't forget the little indicator light in the dash, that could be a 5 or so watt incandescent.

RallyBus · 03-29-2021, 07:21 AM

Thanks all for the help, took all day Saturday but I did find and fix it.

It ended up being a wire had rubbed thru between the window frames going to the front signal on the side of the bus. Assuming it was rubbed thru since there was no accessing it. Hate when wires are run inside of frames.

I think because this was spliced into the main line going to the tail light made it more difficult to locate with the multi-meter. Or my ineptness at using lol

Rewired and all is well now!

ewo1 · 03-29-2021, 08:17 AM

Quote:

Originally Posted by RallyBus

Thanks all for the help, took all day Saturday but I did find and fix it.

It ended up being a wire had rubbed thru between the window frames going to the front signal on the side of the bus. Assuming it was rubbed thru since there was no accessing it. Hate when wires are run inside of frames.

I think because this was spliced into the main line going to the tail light made it more difficult to locate with the multi-meter. Or my ineptness at using lol

Rewired and all is well now!

Awesome news !!!

Pravalas · 04-01-2021, 12:55 PM

Had same problem,back light screw shortcut wire,spend two weeks to figure out

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