Niall HamptonSee other Advice articles filed in ‘Fixtures and fittings’ written by Niall Hampton
HERE ARE THE 18 steps involved in fitting an Al-Ko Mammut caravan mover, plus Doug's verdict on the product and the installation process.
Chassis on caravans manufactured from April 2010 onwards are stamped with the letter M to denote that the necessary holes have been punched in the chassis for the Mammut.
For retro-fitting to chassis on caravans manufactured before April 2010, this additional crossbeam and fittings are required, which lowers the ground clearance by 50mm – less than on any other movers currently available.
The kit comprises all the parts necessary for fit the mover, including spacers, nuts, bolts, tywraps etc. Note the slots in the side of the movers into which the retaining bolts are fitted.
In order to position the movers correctly relative to the tyre tread, the first job was to measure the distance from the tyre sidewall to the chassis. The distance should be 100mm. As it was 130mm, Tom needed to fit 30mm spaces.
From the range of spacers in the kit, Tom chose a 10mm and 20mm which made the necessary 30mm. The two small pieces of plastic rod fit into holes in the spacers to hold them together.
Having fitted the bolts to the movers, Tom then fitted the spacers. The slots in the casing allow for the final adjustment of the drive roller distance from the tread when in the off position.
With the crossmember and mover loosely bolted in position, Tom used a small wooden block supplied in the kit to set it at the correct position from the tread. Having done so, he tightened the three nyloc nuts to 86Nm (64lbft0 (note: lbft not lb/ft or lbs/ft)
Having fitted one mover and crossmember, Tom repeated the job for the mover and crossmember on the other side of the caravan. Following this, he fitted the centre crossmember and secured the assembly using four bolts, four flat washers and four nyloc nuts torqued to 86Nm.
The next job was to fit a grommet in the hole in the chassis and then feed the cable harness through. The operation was then repeated for the other harness. On older chassis which haven’t got this hole punched in them, the harness is fed through the large slotted hole and is similarly protected against chafing.
Both harnesses comprising a live and negative, and a sensor cable, were fed to the middle of the floor and secured to the cross beam with tywraps before being fed back across the floor and up into the offside front seat where the battery compartment was fitted.
Tom also ran the grey cable from the sensor which he had fitted to the A-frame to the hole under the front offside seat, clipping it at intervals to the flange of the A-frame. It too was then fed up into the caravan.
Inside the caravan Tom cut the live cable from each motor and connected it to a fuse block to which he then fitted two 60A fuses. He then fed both the live and negative cables through the existing gland in the battery compartment to the outside.
Next he cut the live and negative cables from both motors to the same length as the existing 12V live and negative battery cables. Having done so, he undid the screws on the live and negative terminal blocks and inserted the cables so that there were three live cables in the positive terminal block and three negative cables in the negative terminal block, following which he retightened the securing screws. The terminal blocks were not connected to the battery at this stage.
Unlike the motor cables, the sensor cable could not be shortened so Tom coiled it and then connected one motor – not both of them at this stage – and its sensor to the sensor cable via the small plug and socket connectors. The design of the plugs and sockets makes it impossible to connect them incorrectly.
It was now time to ‘pair’ the hand unit to the movers so Tom first connected the live and negative terminal blocks to the battery’s live and negative posts.
Having fitted the three AAA batteries supplied, in the hand control, Tom touched it on the A-frame sensor so that it could go through the necessary operations to pair it with the Mammut. At this stage, it paired with only the motor which had been connected to the sensor cable. Once it had done so, Tom connected the second motor to the sensor to complete the pairing.
The control unit has a joystick rather than the more usual push buttons to control the various movements. Tom’s last job was to carry out the final series of checks for which he left the caravan on the lift: roller engagement, forward and backward rotation of the wheels, right and left turns, and roller disengagement.
Having tested the installation, Tom fitted the covers to the terminals and replaced the battery in the compartment. The spare cable was stowed in front of the battery before the retaining strap was fitted.
Two things in particular impressed me about the installation: firstly, the motor cables didn’t need to be shortened other than being cut to the same length as the caravan’s 12V battery cables. This meant that unlike other movers, there was no spare cable from one of the motors which needed to be coiled and stored under the seat.
Secondly, there is no PCB or control panel which has to be fitted on the floor inside the caravan as all the controls are within the motor unit assemblies. There is, however, a slight downside to this in that if anything goes wrong, the complete unit has to be changed as there are no serviceable parts in the units.