jodan0586 Report post Posted June 12, 2016 I have a 2008 Freightliner chassis (Tiffin Pheaton, 40 ft). My Parking Brake Light comes on intermittently while driving down the road. The air pressure is good (brakes do not engage). I have had this problem for about a year. The problem is more constant now, then intermittent and I need to fix it. I have replace the Low Pressure Switch located beneath the Park Brake Release Knob. I have even bypassed the Low Pressure Switch by replacing it with an On/Off switch. The problem continues. I heard there is another type of switch located somewhere else. Can someone tell me where it might be. I have called Gaffney and they told me it was probably something Tiffion hooked to it. I called Tiffin and they said they have nothing connected to that system. Please help. In addition to the brake warning light and buzzer, my driving lights turn off and on in unison with the brake warning light and buzzer. A new development is that my electric slide outs (2) seem to be acting up in that I sometimes have to move the ignition switch on and off a couple times to get them to work. Thanks. ( I have seen several forums related to this problem but have never heard from anyone who had actually corrected it. Share this post Link to post Share on other sites
dickandlois Report post Posted June 13, 2016 16 minutes ago, jodan0586 said: I have a 2008 Freightliner chassis (Tiffin Pheaton, 40 ft). My Parking Brake Light comes on intermittently while driving down the road. The air pressure is good (brakes do not engage). I have had this problem for about a year. The problem is more constant now, then intermittent and I need to fix it. I have replace the Low Pressure Switch located beneath the Park Brake Release Knob. I have even bypassed the Low Pressure Switch by replacing it with an On/Off switch. The problem continues. I heard there is another type of switch located somewhere else. Can someone tell me where it might be. I have called Gaffney and they told me it was probably something Tiffion hooked to it. I called Tiffin and they said they have nothing connected to that system. Please help. In addition to the brake warning light and buzzer, my driving lights turn off and on in unison with the brake warning light and buzzer. A new development is that my electric slide outs (2) seem to be acting up in that I sometimes have to move the ignition switch on and off a couple times to get them to work. Thanks. ( I have seen several forums related to this problem but have never heard from anyone who had actually corrected it. joddan0586, Welcome to the Forum ! The only item that comes to mind at this time is a common ground point, that is ether corroded or possibility loose. Does the low air alarm come off and on when just setting or when it is moving? Or is there any other conditions that tend to affect the alarm ? Rich. Share this post Link to post Share on other sites
jodan0586 Report post Posted June 13, 2016 The alarm sounds while driving. Sometimes it starts immediately after putting the transmission in Drive (after releasing the brake). Most of the time it is activated / deactivated by bumps in the road. Any idea where that common ground would be? Share this post Link to post Share on other sites
wayne77590 Report post Posted June 13, 2016 Carefully reach up under the dash and check to see that all connections are firmly engaged in their sockets. Could happen. Share this post Link to post Share on other sites
dickandlois Report post Posted June 13, 2016 36 minutes ago, jodan0586 said: The alarm sounds while driving. Sometimes it starts immediately after putting the transmission in Drive (after releasing the brake). Most of the time it is activated / deactivated by bumps in the road. Any idea where that common ground would be? Thanks for your reply! the location of the problem form your information can very some depending on model and year. Like Wayne mentioned one needs to look around and check connections. You might be able to get some wiring PDF files for your chassis from Freightliner. You will need the VIN number. Also check with Fleetwood, you will need the FIN number for the coach. there is a plate with that information is often outside on the drives side below the window. Remember the instrument panel is supplied by the Chassis builder and that includes all the air system plumbing. Things can get very confusing if your not into repairing things. Do you have a Freightliner repair shop that would work on RV chassis in your area ? Rich. Share this post Link to post Share on other sites
jodan0586 Report post Posted June 13, 2016 We are currently sitting at a RV Park in Albuquerque. Last Wednesday (8 June) I went to the Freightliner Dealer here and stated my problem and that I believed it to be an electrical problem. He said that I could come to the shop on Friday (10 June) at 6:30 AM and they would PROBABLY be able to take a look at it mid-morning (they operate on a first-come-first-served system). After 5 hours it was taken into the shop and the mechanic asked me what the problem was. He said that the Brake Light was not on when he drove it into the shop. I started the RV, Pushed in the Brake Air Release and put it in Drive. The buzzer and light started immediately. I told him that I had changed the Low Pressure Switch with no change to the problem and that I thought it was an electrical problem, maybe a short or relay or something. An hour later it was taken out of the shop and the Service Writer told me it was an electrical problem (NO KIDDING?). He said they may be able to get it into the shop on the following Tuesday ( 14 June) depending on how long it takes to fix the vehicles ahead of me. I honestly do not have much faith in their ability to find the problem and I can't imagine the cost. I would hate to spend $1000 and have the issue arise again when I am 50 miles away. I specifically chose a Freightliner Dealership because I wanted; it done right. I am just not comfortable with the way things are going. Anyway, since I am stuck here for a week, I decided I might try finding the problem myself. Share this post Link to post Share on other sites
dickandlois Report post Posted June 13, 2016 jodan0586, These are the contact numbers for Freightliner Custom Chassis FCCC SERVICE & TRAINING CENTER 103 Campus Drive Gaffney, SC 29341 P: 855-253-0421 F: 864-206-8755 Hours: Monday-Friday, 8am to 4:30pm EST CUSTOMER SUPPORT CENTER This is the number to call for chassis wiring PDF files and questions regarding issues. 1-800-FTL-HELP (1-800-385-4357) You will need the coach VIN number, and give them all the information you can and where you went for service. Try to get everyone on the same page and hopefully that will help speed up a resolution. Rich. http://www.freightlinerchassis.com/contact-us/#contact-us-2 Share this post Link to post Share on other sites
hermanmullins Report post Posted June 13, 2016 Jordan, This may sound way off the wall, but how is the coolant level in your radiator? Had the same issue with our coach and found it to be coolant level. Yours probably is in the wiring but just wanted to pass on how my issue was solved. Herman Share this post Link to post Share on other sites
jodan0586 Report post Posted June 13, 2016 I appreciate the helpful hints. Cooling level sounds a bit off the wall, as you said, but what the heck. I will check it out. I will also call Gaffney and also try to get wiring diagrams. I researched purchasing the repair manuals, but I was told by the parts guy (in Austin, TX) that they did not include wiring diagrams. Do you know if this is true? Do they include wiring diagrams? Share this post Link to post Share on other sites
dickandlois Report post Posted June 13, 2016 jodan, The Shop manuals do include the wiring diagrams, but they tend to be generic. Getting the PDF files listed for your VIN number will be more likely to match up how your chassis is wired. Rich. Share this post Link to post Share on other sites
jodan0586 Report post Posted June 13, 2016 I spent several hours looking at the wiring diagrams in the owners manual and checking things. I discovered that there is a Green Wire running from the front panel (under drivers window) to the rear panel (last bay on passenger side) that connects to a solenoid. It was barely holding on and came off when I pulled on it. I reattached it and tested the slides. They worked fine. I then closed the coach up and took it for test drive. NO BRAKE LIGHT, NO BEEPING!!!! It appears that both issues were the result of that one loose wire. We will be heading to the Grand Canyon in the morning. Thanks for the help. Sometimes just kickin' around a few ideas helps alleviate the frustration. Share this post Link to post Share on other sites
dickandlois Report post Posted June 13, 2016 Sounds good, In hind sight the clue was the slide out sensor not indicating the slide was in and as soon as you went into drive the alarm sounded as it should. Thanks for sharing your fix with the group. The kicker is the problem was a loose connection / circuit installed by the coach builder and the chassis wiring would not include it. Rich. Share this post Link to post Share on other sites
blakeloke Report post Posted June 13, 2016 Jodan, Herman's explanation above isn't too far from what I was thinking. Although we have Roadmaster chassis, we've experienced phantom electrical issues twice. Both were tied to failed coolant level sensor. Once sensor was replaced the issues went away. Weird thing is, is that my diagnostics reader did not show a code. Last time it happened it took a wiz mobile mechanic with a fancy computer to get the code. Part was cheap. Price of the expert mechanic was well worth it. Blake Share this post Link to post Share on other sites