THE most significant changes in the manufacturers' guidelines for snowplow mounting for the 2012 model year come from Ram Trucks.

And they're minor at that.

Dave Donnelly, senior electrical engineer for the Ram's Commercial Vehicle Team, said the most significant changes come in the 2013 MY with an all-new OEM module that allows enhanced access to the vehicle's messaging and has numerous inputs and outputs for use in a wide range of electrical applications.

For the 2012 model year, there are some improvements in the wiring that modify the rear lighting on chassis cabs.

“The circuits that are found standard on all chassis cab vehicles, located under hood near the brake booster, are heat-shrunk-sealed until needed,” he said. “The circuit definitions are similar in nature to the DGE circuits. The ones numbered 1 through 5 become ground when the corresponding vehicle signal is ‘true’ or ‘on.’ Numbers 6 and 7 allow the customer/upfitter to make these changes to the vehicle without the use of a dealer tool.

“So for example, if the customer wants to change his rear lighting from combined to separated, all he needs to do is attach the corresponding circuit to a ground source, and as long as the circuit remains grounded, the function remains modified. The vehicle checks these circuits on every vehicle startup so they can always be changed back if desired. Same is true about the LED circuit. If the customer is using rear LED lights, then all he needs to do is ground the corresponding circuit and he can use LED rear lighting without having to use resistors or without the need to modify the vehicle with a dealer tool. This circuit is also checked at each startup.”

These circuits are standard on all chassis cabs.

The DGE module is sold by DGE and is not a Ram-truck-owned component. It allows upfitters/customers an interface with some of the most commonly requested electric signals. The DGE module provides relay-control circuits that can be used for various applications, with 25 outputs available.

“The module works by sitting passively on the BUS, reading the messages and driving its outputs low — to ground — when it detects the signal has become active,” Donnelly said. “For example, if the right-turn signal is turned on, the corresponding output of the module goes to ground, thus allowing it to control an additional right-turn signal via a relay without setting any vehicle over-current faults.”

Minor changes

GM's Ken Joye said that for snowplow applications, the new 2012 CK Silverado/Sierra light- and heavy-duty pickups/chassis cabs are generally carryover.

Regular Production Option (RPO) VYU Snowplow Prep Package is highly recommended for snowplow applications. The package helps facilitate snowplow installations, including electrical harness provisions (RPO TRW) for roof-mounted lighting.

Also, in the late 2011 MY, GM added an optional 10,000-lb GVW rating to select 3500HD single-rear-wheel pickup models. This option (RPO C7A) has been carried into 2012 HD models.

Ford's Ken Tyburski, supervisor of product information for special vehicle engineering, said there are no changes that affect snowplows for the SuperDuty. At the time of publication, he had not received the weight ratings, but he said he doesn't anticipate any major changes.

“The electrical is pretty much carryover,” he said. “I haven't seen the weights yet, but I don't anticipate that changing drastically. In general, there is not a lot else changing on the vehicle.”

The following list is for quick reference only. For a comprehensive list of the specific guidelines for each model, refer to the body builders book published by the truck manufacturer.

General Motors

GM 2012 Trailer ratings table GM recommends that when a snowplow is mounted on a vehicle, only one passenger should accompany the driver. More than one passenger may exceed front gross axle weight ratings.

Table 1: GM 2012 HD Pickup Snow Plow Applications and Maximum Plow Weights (click thumbnail to view)

Prior to installing a front-mounted snowplow, the following process should be followed and necessary information obtained:

  • Establish vehicle curb weight.

  • Establish chassis manufacturer's front and rear axle weight ratings.

  • Chevrolet and GMC truck dealers can provide availability, specifications, GVWR, along with front and rear axle weight ratings. For vehicles already built, this information can be found on the certification label installed on the driver's door/frame or provided on the cover of the incomplete vehicle document.

The following information should be obtained and provided by the manufacturers of snowplows and salt spreaders:

  • Specifications, weights, and center of gravity data.

  • Vehicle installation guidelines and instructions.

  • Calculation of weight distribution for the front and rear axles.

The loaded vehicle with driver, passenger, aftermarket accessories, snowplows, spreader, and cargo must not exceed the GVWR or the ratings of the front and rear axles.

In addition, the completed vehicle, with all equipment installed and 400 pounds distributed in the driver-passenger area of the vehicle, must meet GM requirements for the location of the center of gravity. GM provides a schematic with each vehicle, depicting a trapezoid in which the center of gravity of the completed vehicle must fall.

The snowplow manufacturer and the installer of the aftermarket equipment should determine the amount of rear ballast required to ensure that the vehicle, with the attached snowplow and aftermarket equipment, complies with the Allowable Center of Gravity Trapezoid and the resulting front and rear weight distribution ratio as defined in the Allowable Center of Gravity Charts published in the GM manual.

The use of rear ballast weight may be required to prevent exceeding the GAWR of the front axle. The use of rear ballast weight may be required to ensure that the center of gravity location of the completed vehicle, with the attached snowplow and other installed equipment, complies with the Allowable Center of Gravity Trapezoid and the resulting front and rear weight distribution ratio, even though the actual front weight may be less than the GAWR of the front axle. In either case, the rear ballast weight should be securely attached in the cargo box or behind the rear axle of the vehicle in a manner that prevents it from moving during driving and stopping.

To help avoid personal injury, refer to Z-height setting procedure before adjusting torsion bars. If torsion bars are adjusted for aftermarket equipment, be sure to return them to specification when the equipment is removed. Otherwise, a front shock absorber may dislodge and damage a front brake line. This could result in an accident when minimum stopping distances are required.

Ford Trucks

GM 2012 Trailer ratings table Minimum recommended equipment for the F-150: regular cab 4×4, 144.5" wheelbase, 8' pickup box; or SuperCab 4×4, 163" wheelbase, 8' pickup box.

Table 2: Ford 2012 Front/Rear Axle Weight Limits (click thumbnail to view)

Snowplow prep package (option code 63A) includes FGAWR upgrade to 4300 lb (4300 lb spring rating).

Heavy Duty Payload package (option code 627) includes: 8200-lb GVWR; 4050-lb FGAWR (4050-lb spring rating); 4800-lb RGAWR (4900-lb spring rating); rear axle capacity upgrade to 5300 lb and 10.5” diameter ring gear 4.10 ratio, limited-slip not included but available; 17"x7.5" J 7-lug steel wheels; LT245/70Rx17D BSW all-season tires (5); 5.4L, 3-valve V8 engine, 4R75E automatic transmission; Super Engine Cooling (1.42" core thickness); auxiliary transmission air cooler, oil-to-water increased to 9-channel/18-plate; battery upgrade to 72 amp-hr/650 CCA; fuel tank (35.7-gallon capacity).

Snowplow weights (maximum recommended):

  • Regular Cab 750 lb (700 lb removable plow assembly plus 50 lb permanently attached hardware).

  • SuperCab 610 lb (560 lb removable plow assembly plus 50 lb permanently attached hardware).

These snowplow weight limits are based upon a vehicle built with maximum buildable Ford option content, driver plus one front seat passenger, 150 lb each, 800 lb of ballast weight rearward of the rear axle, and additional assumptions for commercially available snowplow assembly weights and mounting location.

The vehicle must not be operated when overloaded. A vehicle is overloaded when the weight of the completed vehicle with aftermarket equipment installed, plus driver, passengers, and cargo, exceeds either the FGAWR, RGAWR, or GVWR established by Ford Motor Co and displayed on the Safety Compliance Certification Label.

The addition of ballast weight placed rearward of the rear axle may be required to prevent exceeding FGAWR, and provide good vehicle braking and handling. The ballast should be attached securely to the vehicle with consideration for the normal driving dynamics of snowplowing and occupant safety in accidents.

For Ford completed vehicles of 10,000 GVWR or less, the weight of permanently attached aftermarket equipment must not exceed the Total Accessory Reserve Capacity displayed on the Safety Compliance Certification Label to maintain the compliance representation that came with the Ford-built vehicle. Exceeding TARC will require recertification. This applies only to the permanently attached equipment, such as the snowplow frame mounting hardware, and not to the removable portion of the snowplow blade assembly.

Front end wheel alignment (toe) and headlight aim may require readjustment after installation of snowplow equipment. Failure to reset front wheel alignment may cause premature uneven tire wear. If required, reset to chassis manufacturer's specifications found in the Ford Shop Manual.

Installation of any inductive load devices such as electric motors, or electric clutches for clutch pumps, must not be connected to Ford vehicle wiring or fuse panels. Power for such devices should be taken directly from the battery or starter motor relay power terminal. Control of these devices should be achieved via relays. No direct current path should exist between Ford vehicle wiring and the installed load that is not filtered by the battery. These recommendations are intended to eliminate or minimize any induced reverse voltage into the Ford circuitry.

Ram Trucks

The loaded vehicle, including all aftermarket accessories, the snowplow system, passengers, and cargo, must not exceed the gross vehicle weight (GVW), front or rear gross axle weight (GAW) ratings specified on the Safety Compliance Certification label located in the driver's side door opening.

The empty truck with all permanently attached accessories and snowplow components must not exceed 62% of its total weight on the front axle to comply with FMVSS/CMVSR 105 Brake Certification. Permanently attached snowplow parts are those parts not easily removed when the blade is removed. The permanently attached parts are: subframe, hydraulic pump, hydraulic lift cylinder, lamps, wiring, snowplow controls, etc. If the front axle loading exceeds either 62% of the empty truck total weight, or the front GAWR, ballast compensating weight must be securely attached at the rear of the truck to bring front axle weight within weight specifications.

Notes for heavy-duty snowplows:

  • At any time, the maximum number of occupants in the truck must not exceed two.

  • Under any circumstances, vehicles should not exceed GVWR (Gross Vehicle Weight Rating), front or rear GAWRs (Gross Axle Weight Ratings).

  • Snowplow prep packages are not available with Sport (AAG) package.

  • Cargo capacity will be reduced by the addition of options.

  • Ballast should be securely attached inside the box at 9" from the rear tailgate for pickups.

  • The total weight of permanently attached hardware should not exceed 125 lb.

  • Max snowplow weight should not exceed values for models shown in this section.