Technical Ducato X250 Wiper Motor Replacement

[Anthony489]

The front wipers on my 2009 Ducato based Motorhome would sometimes not start for several seconds, all modes affected. Once going they worked and parked normally. After a few weeks the seconds of waiting had worsened into heart-stopping minutes. Rather dangerous when you have to pull over and wait till they decide to start !

Tests with a voltmeter showed +12 volts and ground were ok at the motor, and that the body computer was sending the right signals to the motor but it wasn't responding. Incidentally, the high and low speed relays are inside the motor casing, so two low current control signals (12V = OFF, 0V = ON) are sent from the body computer. There is also a signal going back to tell the computer if the wipers are parked. I could hear the relays faintly click. By chance the motor was playing up at the time of testing, and an experimental tap on its casing with a screwdriver made it start to work! I was then confident the motor was at fault. Just as well, as a body computer is £££s and needs coding.

I sourced a new Magneti Marelli motor from Euro Car Parts for £107 (Main dealer price £187). To swap the motor you need to remove the wiper mechanism. Firstly take off the wiper arms from the spindles, these may well be tightly corroded on - I used a 2 legged puller. Two of the three bolt heads for the mechanism are hidden below the plastic gutter at the base of the windscreen on the driver's side, so this too has to come off. It's held by 3 visible self tappers, plus 5 hidden plastic mushroom clips behind. I broke 2 of these when easing it off, and had to get new ones from the main dealer at £2 each (crazy - must cost 2p each to make). I couldn't get the gutter off without removing the bonnet ( 2 bolts on each hinge) which made access a whole lot easier. Mark round the brackets before unscrewing so you don't lose the bonnet alignment. With the motor half out its easier to release the 5 pin connector, which has a latch at the top that needs lifting - very hard to see in-situ. Whilst the mechanism was out I took out the arm spindles (one circlip each) and greased them. Or you could pay a bit more and get a combined motor and mechanism assembly.

When putting things back I used some silicone spray on the plastic clips to help ease them in, and some black RTV sealer along the top inside edge of the gutter to stop water from the windscreen leaking behind. I also sealed the feeble centre overlap joint to the other half of the gutter, to stop water leaking down onto the engine. Make sure you transfer over the pathetic piece of foam plastic that is supposed to keep water off the motor.

It might be feasible to swap the motor in-situ, but access to the 4 fixing screws is very tight so I didn't attempt this method.

I now have working wipers - very pleasing.

I couldn't resist taking the cylindrical cover off the old motor. The 3 brushes looked fine, but I suspect the bimetallic thermal/overload trip device on the PCB had developed a dodgy internal contact which would have open-circuited the earth return from the motor, stopping both high and low speeds.

Motorhomes seem to have more than their fair share of electrical gremlins, probably because they sit around unused in winter and the damp gets in without being regularly warmed up to dry it out.

 

[philgb]

Thanks Anthony, am just replacing my wiper motor and linkage, typically our camper wipers ground to a stuttrring stop in the rain.
Sourced the replacement from fast parts for £119 for motor and linkage. Ordered scuttle fastening studs ebay £6 for pack of 10.
Am going to seal the scuttle up,
Cheers for posting your how to check and replace post

 

[Tifoso]

Thank you for sharing. The wipers of my 2015 Ducato stopped working some time ago and after checking both the dashboard and motrcompartment fuses I thought the motor must be blown. After reading about the overcurrent protection relay being in the motor I decided
to give a few blows with the hammer on the motor. This did the job and now my Ducato is wiping again.

 

[nigelvan]

Hi Anthony, me again . Yesterday we left for our 6 month trip and after using the wipers and a short stop, they stopped responding entirely and the issue is exactly as you described above (got 12V at the connector, hear the relay clicking...). We now parked at family and I found a new motor on Amazon with Prime delivery expected tomorrow.
How do you disconnect the linkage from the motor?

 

[Anthony489]

Hi Nigelvan

This was a while ago, so I cannot remember for sure, it can't have been too difficult.

From my fallible memory, the motor has a crank arm a couple of inches long which is bolted to the end of its spindle, but some replacement motors come with a welded on crank.

On the outer end of the crank is a ball , over which a socket on the outer arm pushes on. To remove, gently lever with a screwdriver and it should just pop off. The other arm has a plain bush, so comes off last and goes on first.

 

[camionpilot]

Grease the drive spindles as Anthony did when apart [ or when assembling them from new ] as the crap alloy has no bushings or lubrication access and the steel drive runs direct on the alloy which tends to seize up snap and fail at around 60/70 kms .

 

[nigelvan]

Yes! I got it apart and one side was really corroded. It's all greased up now and moving freely. As we have nothing to do while waiting for the new motor, we took apart the old one and the motor itself is still operational! So, there must be something wrong with the electronics which are impossible to access. The gears and power supply to the motor can be accessed by drilling away the rivets. The relay can still be heard when pushing the wiper arm at the wheel upwards.

On the picture you can see the worm wheel and the gears, with a conductive area telling the unit when the start position is reached (I think). Anyway even if it would work the part can't be trusted anymore so will wait from the part from Amazon which is made by Frankberg. Can't really be picky about the brand because we want to leave asap. There's also a Ridex part for about 25€.

 

[nigelvan]

Update: new motor arrived and turns!

I did a few tests with the old motor, with the motor disconnected I got 12V at the PCB contacts. I then soldered wires between PCB and motor so I could measure voltage, which was 0V with the motor connected, I tried the first experiment again and got 0V now again. So my conclusion is that the relay might have become erratic and the thermal overload is still intact. The motor itself is still turning.

Concerning the wiper assembly I had to hammer out the spindle on driver's side because the bushings (if that is the correct English word) were so corroded. After sanding and greasing the assembly has almost no resistance anymore.

So, did the overload protection fail me and instead the relay/internal circuit got too hot/burnt? Without load the motor draws 9A at 8-9V. My power supply maxes out at 10A so I couldn't test the motor at full power. The resistance of the rotor is 0.4-0.5 ohm, at 12V it would draw then about 24A, of course this would rise if there's a load on the motor such a the corroded wiper assembly. But this static testing doesn't say much because according to the power supply reading, the resistance is (9V/9A = 1 ohm) 1ohm.

The fuse is 30A and didn't blow? I had a case earlier where a high current just unsoldered wiring from a PCB, maybe this happened? Unfortunately I don't have any schematics on the motor itself so the quest stops here as the new motor has arrived.

I just wanted to leave this here for future reference in case someone else wants to troubleshoot.