Ethanol
Now that the government has approved 15 percent ethanol (E15) gasoline, how is this going to affect our 2007 GM Workhorse 8.1-liter gas engine?
Clifford & Barbara Irwin, F313712
Crossville, Tennessee
In the owners manuals that you received with your motorhome, you should be able to find this information. If not, locate the telephone number for General Motors and call the company to discuss your concerns with a representative.
What you should know is that the E10 gasoline that has been in wide use for several years will still be available. The E15 will be only for light-duty vehicles model-years 2001 and newer. The U.S. government requires that the E15 pumps include a distinctive orange-and-black label to keep motorists from using the wrong blend in their vehicles. Currently, the federal government does not require E10 pumps to display a special label, although some states do mandate it.
Towable Brakes
I tow a four-door 2010 Jeep Wrangler behind my 2008 Newmar, which has a 340-horsepower Cummins engine with an exhaust brake. I purchased a Roadmaster Add-A-Brake and had it wired and set up in my Jeep. When the motorhome’s brakes are applied, a red light illuminates on the dash to indicate that the brakes are being applied on the Jeep. I noticed that when using the motorhome’s exhaust brake, the red light comes on. I called Roadmaster and they told me that the Add-A-Brake is activated when the brake lights come on and that the exhaust brake turns on the brake lights. Bottom line is that I have two options: burn out the brakes on the Jeep when going down a long hill with the exhaust brake on, or turn off the exhaust brake to save the brakes on the Jeep!
Gary Mcmanus, F124382
Baker City, Oregon
To find out more about this potential problem with the Add-a-Brake, we contacted technical support representatives at Roadmaster Inc. to determine how the braking system can be used in conjunction with a motorhome’s exhaust brake.
According to the technical service rep, the Add-A-Brake has extended braking protection and will automatically release braking pressure after an extended period of continuous braking. To regain supplemental braking in the towed vehicle, the motorhome’s brake pedal must be released and depressed.
Activating the exhaust brake in some motorhomes also may illuminate the motorhome brake lights. When the Add-A-Brake is activated by the exhaust brake, it will automatically release braking pressure after an extended period of continuous braking. To regain supplemental braking in the towed vehicle and use an exhaust brake system of this type, cycle the exhaust brake on and off.
The Add-A-Brake has two built-in safeguards to protect the towed vehicle’s brakes. If, for any reason, the Add-A-Brake depresses the towed vehicle’s brake pedal continuously for approximately 20 seconds, the motorhome monitor will signal an audio alert. In addition to the audio alert, the monitor LED will illuminate. Stop immediately after an audio alert from the monitor. The audio alert and illuminated LED indicate that the towed vehicle’s brake pedal is being depressed. Significant brake system damage to the towed vehicle, as well as other consequential damage, may result. Identify and correct the cause of the audio alert before using the Add-A-Brake. If the monitor signals you with an audio alert, stop immediately. Identify and correct the cause of the audio alert before using the Add-A-Brake. Failure to respond to an audio alert, as indicated above, may cause property damage, personal injury, or even death.
For more information, contact Roadmaster Inc. at (800) 669-9690.
Towing Lights
Would you please tell me which lights must be activated on the towed vehicle by the motorhome? I assume that I should be able to operate both rear turn signals, both brake lights and hazard flashers, the rear running lights, and the license plate lights when the vehicles are connected. If this is the case, how many diodes would be required, and where would the wires from the towed vehicle socket be connected to the vehicle’s existing wiring?
Bob Bielemeier, F287330
Hayesville, North Carolina
You are correct in your description of the lights needed for the towed vehicle. However, each vehicle is different. For example, some motorhomes and many cars use different circuits for brake lights and turn signals (turn signals and hazards will use the same lights and circuits) — this used to be called the “European style.” Others — such as Jeeps — use the same lights for both functions. Diodes are used in the turn signal/brake light circuits as one-way “valves” that allow the juice to flow in just one direction and not the other. If you buy a wiring kit that includes diodes at an RV store, the kit should include the proper wiring diagram (the ones I’ve purchased always have). It is then up to you to decide where the diodes should be installed on the wiring.
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