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It began as a common problem: cruise control would not latch. Lots of owners have commented about having to cycle their Smartwheel Cruise Control ON/OFF switches before latching can occur. Then, another oddity: turning the dash lights rheostat on would unlatch/disengage the cruise control. Later, the system stopped working entirely. I could, on occasion, get it to engage for brief periods. No single event ever defined the inevitable unlatching, the longest it went without disengaging was a half-hour, during Interstate driving on a recent trip. When I contacted our chassis tech support representative, he said such issues are usually a Caterpillar ECM problem. Since, technically, the failure was an intermittent issue, I suspected the old culprits of corrosion, broken wires or looseness that plague all older chassis. The ECM is connected by two complex multi-pin plugs, in an area prone to spray, dirt. On the 2006 C13, it is located just forward of the fuel filter. The aft of these two plugs, taking in yellow braided wires, handles engine sensors. The smaller attends to other functions, like cruise control. I crawled underneath, used a 1/8" allen key to loosen the smaller of these, sprayed it with electronics cleaner, carefully snugged the plug into place and tightened the hold down screw. Still, no cruise. "It's the chassis ECM, not ours," insisted the Caterpillar shop foreman, when I raised the white flag and called for an appointment. He added that, for no charge, he'd plug in the ECM and prove his point. I hastily agreed, hung up and started driving to Holt Caterpiller of Fort Worth. They are the same folks who replaced all of my intake solenoids, accessing the engine by dismantling the bedroom closet -- they reassembled the doorframe and rehung the doors without leaving a trace -- for less than $1800. To shorten the story, let it suffice to say the computer revealed the "Inactive" status of the cruise control, and the technician could get it latch, but only in the high-idle mode. We agreed to a road trip with me driving and him using the laptop. He threw the switches for Retarder modes, Adaptive Cruise enabling, experimented with some other ideas on the screen while I drove. Eventually, I had cruise control with unlatching anytime the engine brake power was ON or the dash lights were illuminated. For the life of me, I cannot understand the latter, unless it is an inhibit to prevent night use of VORAD, the primative adaptive cruise control with which the original RV was equipped, later decommissioned. Finally, the technician mentioned that my brakes were showing engaged on an intermittent basis. We opened the generator bay and examined the backside of the pedal assembly. Two simple pressure switches are there: the inboard attends to cruise control, the outboard activates the brake lights. I instantly found a wobbly spade connector on the former, and when I crushed the interior slightly and slid it back into place, that line on his screen obediently said "OFF" and remained that way. All the way home -- a trip of forty miles -- the cruise remained engaged. Now, with a long trip to Florida looming, I have the simple luxury of driving with my fingertips!

I am near Flagstaff AZ and have a check engine light on. Anyone recommend a good repair facility for a Cat engine?

My CAT 3126B air inlet heater appears to be working OK, though I haven't spent a lot of time in really cold climates. That may change this winter. I have a diesel furnace that also heats the hot water. Part of the system consists of a heat exchanger that uses engine coolant to heat the hydronic system coolant (and HWH) to warm the entire coach while driving down the road. It works very well without using the furnace. But it won't work in reverse without another electric pump to circulate the engine coolant when the engine is off; warming the block while using the diesel furnace. Is this feasible? Will I need to bypass the new pump when the engine is running? Will the 3126B thermostats affect the flow? Is the direction of flow important? Or another option: I see immersion type electric block heaters for sale, supposedly for the 3126B engine, but can't find any installation data. Is there an unused port somewhere on the 3126B block where this of block heater is typically installed? I lean toward the added pump system since it won't require 120 vac all night to heat the engine. Not always on shore power. Or is the air inlet heater all I need for temperatures down to and below zero degrees F at high altitudes with thin air? Chuck