duanelin Report post Posted July 19, 2017 I discovered yesterday my brake lights were not working. Tail lights and turn signals all work. I checked the fuse in the front run bay it is good. Any suggestions on where to look next? . 2012 Monaco Diplomat 43 DFT Share this post Link to post Share on other sites
wildebill308 Report post Posted July 19, 2017 9 minutes ago, Duanelin said: I discovered yesterday my brake lights were not working. Tail lights and turn signals all work. I checked the fuse in the front run bay it is good. Any suggestions on where to look next? . 2012 Monaco Diplomat 43 DFT Have you checked the bulbs? Bill Share this post Link to post Share on other sites
duanelin Report post Posted July 19, 2017 Bill The bulbs are good the Turn signals work. No brake light on toad also. I am wondering if there is a relay that is not working, I have replaced the switch on the treadle valve twice due to lights staying on. I will check that switch tomorrow. to hot over Onan to check today it was on for over 56 hours straight on the eay back from Indianopolis Duane Share this post Link to post Share on other sites
kaypsmith Report post Posted July 19, 2017 When was the last time you purged your drier, and air tanks? Share this post Link to post Share on other sites
wildebill308 Report post Posted July 19, 2017 It does sound like a switch problem as the brake lights on the toad don't work. Check for power at the switch. I bet there is a separate element in the bulb for the brake light. Bill Share this post Link to post Share on other sites
dickandlois Report post Posted July 19, 2017 4 hours ago, Duanelin said: Bill The bulbs are good the Turn signals work. No brake light on toad also. I am wondering if there is a relay that is not working, I have replaced the switch on the treadle valve twice due to lights staying on. I will check that switch tomorrow. to hot over Onan to check today it was on for over 56 hours straight on the eay back from Indianopolis Duane You mentioned that both the coach and towd lights are not operating. If it was just the towd brake lights - in many coaches there is a fuse / relay box added to the wiring and that box is most often located in the right rear compartment bay area. There are cases when it is mounted on the left rear side bay area. The coach wiring for your model year very likely has a relay in the Left front, driver side electrical bay for the brake lights. Check for a bad fuse or connection at the relay. There is a electrical switch under the air break relay that controls the break lights. That you mentioned so there Could be a loose or broken connection in that area also. There is a slim chance of a connection issue in the turn signal switch, but your model year coach should have a separate yellow turn signal bulb and red brake light bulbs. Rich. Share this post Link to post Share on other sites
duanelin Report post Posted July 19, 2017 Rich Turn Signals are red there are no yellow bulbs Share this post Link to post Share on other sites
dickandlois Report post Posted July 19, 2017 Duanelin, No yellow turn bulbs would mean that the break light circuit goes through the turn signal circuit. Do the Turn signals work? If they work then you need to check the turn signal circuit ! A bad connection(s) in the circuit under the steering wheel. Would be my best bet in that case. Rich. Share this post Link to post Share on other sites
hermanmullins Report post Posted July 19, 2017 It is amazing what all go through the turn signal switch. My thought would be to replace the switch. However this does require removing the steering wheel in most cases. But before I did that I would make sure the brake light switch is good. Herman Share this post Link to post Share on other sites
duanelin Report post Posted July 19, 2017 The turn signals work Share this post Link to post Share on other sites
hermanmullins Report post Posted July 19, 2017 Duane, There is a lot more going on in the switch then just the turn signal. It is amazing of how much is in it. Herman Share this post Link to post Share on other sites
dickandlois Report post Posted July 19, 2017 10 hours ago, Duanelin said: Rich Turn Signals are red there are no yellow bulbs That kind of takes the power circuit for the brake lights out of the mix in most cases, because all the flasher does is interrupt the 12 volt break light power intermittently. But make sure all the connections between the steering wheel harness connection and the section of the wiring harness under the dash are good at both sides of the connectors. Using a test light or volt meter you should see the break light voltage come and go as you depress the brake peddle, IF there is no power on one of the wires in these connectors (both sides) THEN recheck the brake switch and wiring you mentioned replacing in a post before, getting into removing the steering wheel and removing the turn signal switch. Common steering wiring can be a test of ones skills and when a smart wheel system is thrown into the mix - it could get interesting! So if your coach has a smart wheel, then getting some information and wiring information on it would be a good plan. Rich. Duanelin , You might just try a new turn signal flasher and see if the rear turn signals flash - Stranger things have happened with some of the new wiring layouts. !!!!! Share this post Link to post Share on other sites
kaypsmith Report post Posted July 20, 2017 Duane, I do not know about your model, but many air brake systems use a pressure switch that activates the relay for the brake lights. If yours is one of this type. and you know where to locate it, just a little moisture from either water or oil, sometimes debris lodged in the inlet will cause the brake lights to either stay on, or off. This is why I asked the question about purging the drier and air tanks. Since you have already replaced the switch on the treadle valve twice makes me think that your air system may be in need of some attention. The air drier is usually located up front and just before the brake system, there is usually a pull ring located at the bottom of that canister that needs bleeding regularly, also all the air tanks need to be purged often. If that switch that you have replaced before screws into an air supply of any type, I would remove it again, and let the system purge from that point after purging all other points, you will need to pump (fan) the brake pedal with air pressure built up in order to do that. Also, clean the inside of that switch with regular rubbing alcohol, this will dry out out any water accumulation that might be inside. Of course if you don't have air brakes, none of this applies, but with a 43 ft pusher, I bet that you do. Good luck with making them work again. Share this post Link to post Share on other sites
duanelin Report post Posted July 27, 2017 Found the problem today. There are 2 fuses for the brake lights. One powers the brake light switch. The second one is after the relay in the front run bay that powers the lights. It is not marked well on the print on the door of thr FRB Duane Share this post Link to post Share on other sites
wolfe10 Report post Posted July 27, 2017 Duane, Thanks for coming back with the answer. Will likely help someone else in the future. Share this post Link to post Share on other sites
wildebill308 Report post Posted July 28, 2017 Yes thanks for letting us know. Bill Share this post Link to post Share on other sites
hermanmullins Report post Posted July 28, 2017 One fuse no problem. Two, who would of Thunk. Thanks for letting everyone know. Herman Share this post Link to post Share on other sites
jleamont Report post Posted July 28, 2017 Am I the only one wondering why the fuse was open? Share this post Link to post Share on other sites
hermanmullins Report post Posted July 28, 2017 Joe I always wonder what may have tripped, blown, a fuse. Some times I will replace a fuse and think I will check it out later. Then I will forget it and never have it blow again. If it blows again then that will really get my attention. (??????? what dune it?) Herman Share this post Link to post Share on other sites
kaypsmith Report post Posted July 28, 2017 On 7/18/2017 at 8:01 PM, Duanelin said: The bulbs are good the Turn signals work. No brake light on toad also. I am wondering if there is a relay that is not working, I have replaced the switch on the treadle valve twice due to lights staying on. I will check that switch tomorrow. to hot over Onan to check today it was on for over 56 hours straight on the eay back from Indianopolis Joe, this was the op's second post, 56 hours of staying on would be my guess, that's a lot of heat since the filament for brake lights is twice as bright as the tail light. Share this post Link to post Share on other sites
jleamont Report post Posted July 28, 2017 51 minutes ago, kaypsmith said: Joe, this was the op's second post, 56 hours of staying on would be my guess, that's a lot of heat since the filament for brake lights is twice as bright as the tail light. I missed that part....thanks, now that would make sense! Share this post Link to post Share on other sites
duanelin Report post Posted July 29, 2017 Joe, My Onan was on for 56 Hours. It was too hot to get to the brake switch under the front cap. Outside temp was over 90 that day. I may have a short in the toad wiring. I have not hooked that up yet. I do not know how long we drove without brake lights. Duane Share this post Link to post Share on other sites
