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Magnaryder02 · 11-16-2020, 07:32 PM

Ok, keeping on pressing forward figuring out issues with this coach. Next on the list is the brake lights.

First, the lights themselves work as they are shared with the running lights and the turn signals and both of those work.

Second, I checked the 10a fuse labeled brake in the fuse box in the engine compartment and it is good.

Third, I checked for voltage at the brake pedal switch and was getting voltage when I depressed the brake pedal. So I would assume that the switch is working.

This leads me to believe that there may be a relay or such that is not working, but I can not find where this relay is. I have a bunch of wiring diagrams, but nowhere can I find anything to do with the brakes, brake lights, or associated wiring. Looking for if there is a relay and where it might be. There a ton of relays under the dash, but nothing is labeled and when I try and trace the wire from the switch it just goes into the main harness.

Skip426 · 11-16-2020, 11:24 PM

What chassis is your coach built on ? Ford ? Workhorse ?

Have you tested for brake light power from the brake light switch , into and out of the turn signal switch?

Magnaryder02 · 11-17-2020, 01:12 AM

2002 bounder 36s workhorse chassis.

Not sure exactly what you mean?

Skip426 · 11-17-2020, 12:06 PM

Quote:

Originally Posted by Magnaryder02

2002 bounder 36s workhorse chassis.

Not sure exactly what you mean?

OK ; in a situation where the vehicle uses the same bulb/filament for signal and brake light at the rear of the vehicle . The wire that supplies power for both runs from the Turn Signal Switch to the rear of the vehicle .
Power from the brake light switch , goes into the TSS , and is split to left and right brake light power when the signals are not in use.
When the signals are in use , movable contacts internal in the TSS , supply power from the signal flasher to the wire instead of power from the brake light switch, on the side your signaling to , while still maintaining contact for brake light power to go to the other side.
So you have to test , for brake light switch power supplied to the TSS ( one wire in ) and power from the TSS to the rear ( two wires out. ) So if operating properly back probing the connectors with a 12 volt test light, will show wiring for the TSS will have 3 wires steadily powered , when the brakes are applied . Then you've eliminated the TSS as your no brake lights problem and can move to other areas.

Other wiring into the switch will supply signal flasher power and 4 way flasher power and flash when back probing with a test light.

Magnaryder02 · 11-21-2020, 08:52 PM

Ok hopefully I can get some suggestions, I am going to try to go at this tomorrow. I spent 3 hours today with not much progress. I get the basic concept, but the wires are not lining up.

I used a continuity tester to try and trace out the wires to the turn signal switch and could not trace a wire. According to the wiring diagram I found the white wire should go straight to the TSS, but I traced the white wire to a connector for a module under the dash, possibly the cruise module? After that I lost it. Wiring diagrams I have do not match up to the wires at the TSS.

Skip426 · 11-22-2020, 10:49 AM

Ok , I have to ask if your brake light switch looks like the diagram below and has two wiring connectors ?

1/2 of the switch is involved with the brake lights the other half the cruise control .
So it is possible for 1/2 the switch to fail with no brake lights being the problem .

Also if you could clarify , what series of Workhorse chassis you have .
Info I have is for a " W " series and if memory serves in 2002 the " P " series was still in production .

clifford j · 11-22-2020, 11:13 AM

Magnary,,, listen to SKIP 426, he's dead on !!

CLIFFORD

Magnaryder02 · 11-22-2020, 12:57 PM

Quote:

Originally Posted by Skip426

Ok , I have to ask if your brake light switch looks like the diagram below and has two wiring connectors ?

1/2 of the switch is involved with the brake lights the other half the cruise control .
So it is possible for 1/2 the switch to fail with no brake lights being the problem .

Also if you could clarify , what series of Workhorse chassis you have .
Info I have is for a " W " series and if memory serves in 2002 the " P " series was still in production .

It is the W22 chassis. I have the type of brake switch with 2 connectors a 3 wire and a 2 wire. I have been focusing on the 3 wire connector. Orange is always hot and white and blue show 12v when pedal is depressed. White is my target for brake lights and I think blue is for the brake booster.

Skip426 · 11-22-2020, 01:41 PM

Quote:

Originally Posted by Magnaryder02

It is the W22 chassis. I have the type of brake switch with 2 connectors a 3 wire and a 2 wire. I have been focusing on the 3 wire connector. Orange is always hot and white and blue show 12v when pedal is depressed. White is my target for brake lights and I think blue is for the brake booster.

Ok , you mentioned diagrams in an earlier post , do you have diagrams or schematics , there is a difference .
On a schematic , you should be able to follow every wire to any destination and color changes ; if any ; should be apparent and every module would be named.

If you follow the blue wire in your paperwork are you positive it goes to the " brake booster" or ABS pump .
I take it that your brake light switch and wiring look like the photo below ; where another member as tapped in for an electric trailer brake controller.

Magnaryder02 · 11-22-2020, 01:44 PM

Quote:

Originally Posted by Skip426

Ok , you mentioned diagrams in an earlier post , do you have diagrams or schematics , there is a difference .
On a schematic , you should be able to follow every wire to any destination and color changes ; if any ; should be apparent and every module would be named.

If you follow the blue wire in your paperwork are you positive it goes to the " brake booster" or ABS pump .
I take it that your brake light switch and wiring look like the photo below ; where another member as tapped in for an electric trailer brake controller.

Yes my switch looks exactly like that minus the wire tap. I dont have the drawing in front of me, but it's the drawing I pulled from a workhorse diagram. I'll snap a picture when I get the chance.

Magnaryder02 · 11-22-2020, 02:30 PM

Here is the diagram I am following.

Skip426 · 11-22-2020, 03:12 PM

Ok from the photo you're correct in following the white wire and through connector C207 the color doesn't change , but you're saying there is no white wire as an input at the multi function switch connectors.

I've been looking for a full chassis schematic online , and I'll see if there's information anywhere about the multi function switch pin out .
I'll be back .

Magnaryder02 · 11-22-2020, 04:04 PM

There are 2 white wires in the multifunction switch. Neither is a direct path with continuity, one has a resistance around 700 ohms. In doing some more searching I found these diagrams which show a splice fron the brake switch. I'm having a harder time tracing the circuit on these.

Skip426 · 11-22-2020, 04:26 PM

One of the connectors on the multi function switch is for turn signal operation ,the other connector is for the wiper/cruise functions .

So the white wire showing resistance is probably to do with wiper function .

If the white wire in the switch wiring , lines up with a white wire in the dash side of the connector that's where to check for power; from the brake light switch .
Look at the connector with wire colors that match , the first schematic you posted .
When testing the internal connections of the switch , you should have continuity ; zero ohms ; between the white wire and the colors for rear brake/ signal , as per the schematic.