240 General: £15 modern wiper motor upgrade

[Juular]

I've long been irritated by how poor the wipers are on my 240. From what I read this is fairly typical across 240s, but on my car the wiper motor has started properly giving up. As well as randomly blowing fuses, the motor is now oscillating inside the casing causing it to grind and judder. I've replaced everything replaceable, it's just had enough.

The original motors are now difficult to find, and although aftermarket versions were available at one point, they were very expensive. Replacing the original with another of the same type doesn't really change that they will still be a bit slow and rubbish.

This is really putting a downer on my enjoyment of the car, so I decided something needed to be done.

I decided to try another way. I picked up a used motor from a 2001 Volvo S40 for £15. These are very easy to find and you can even buy them new off the shelf for a fraction of cost of the 240 motor.



There are some differences.

-The connector plug is different.

-The mounting bolt locations are on the wrong side.

-The spindle shaft is too short to reach the wiper linkages.

I set about sorting these issues and managed to adapt it to fit the 240 wiper linkage perfectly, using some fairly common garden shed tools. Here's how I went about it.

Firstly, the electrical side is compatible, it just needs patched into the 240's connector. You don't need to change the wiper relay or anything else.

This was a fairly straightforward case of soldering on some wires with spade connectors on the other end which plugged into the 240's connector. Here's what each pin on the S40 motor does, and which colour on the connector it should go to.



And here it is running off the 240's connector, on intermittent wipe.

[YOUTUBE]https://www.youtube.com/watch?v=p5bnj8IMI0I[/YOUTUBE]

It'll do everything it's supposed to, including low, high, intermittent, and will park when you turn the ignition on.

The main difference is that the S40 unit doesn't ground to the body like the 240 one does, so you should run the far left ground pin to the battery negative terminal, or bolt it into a bit of clean chassis sanded down to make good contact.

Now to make it physically fit.

Extending the motor shaft

To extend the spindle I used an M8 connector nut, which costs around £1 for a bag of ten.

I made a centre punch mark close to one end.



Drilled a 3mm hole.



I then screwed the connector nut onto the motor shaft with the hole at the motor end, then continued drilling the 3mm hole through into the motor shaft about halfway through.



I then tapped this to M4.



And screwed in an M4 machine screw.



I then filed this flat and set it in place with epoxy.





This should ensure that the connector nut never unwinds itself as the motor turns.

Furthermore, and luckily, this extends the shaft exactly the right amount to fit down through the bulkhead into the passenger footwell area.

There are less complicated alternatives here, you could probably use red threadlocker to stick the connector nut to the shaft, but I used what I had lying around.

You could also tack weld it in a couple of places to the shaft, although I was concerned about heating up the nylon gear wheel inside the motor too much.

Essentially you just have to find a way to stop the connector nut unwinding itself because of the rotation of the motor.

Adapting the bolt holes.

The motor has the threaded bolt holes on the opposite side of the motor from the 240 one. I decided to make an adapter plate to overcome this.

This involved getting a scrap bit of 2mm steel and marking and drilling the holes for the old motor, then aligning the new motor in exactly the same place and drilling its holes.

It's important to get the motors close to the same orientation, so mark the centreline from the old motor and try to get the new one to match it.









You can then bolt the S40 motor onto the plate, then bolt the motor onto the car.







There are alternatives to using an adapter plate. You could drill 6mm holes down through the bulkhead and bolt the motor on from the other side. You could fit some 6mm threaded bar into the motor bolt holes to make this even easier. But I didn't want to modify my car in this way.

Fitting the shaft to the crank.

The final step is to find a way to fit the original wiper crank onto the shaft, and ensure that it can't rotate its way out of alignment while the wipers are working.

The original 240 motor is keyed so that the crank fits on and can't rotate. You could try to replicate this in some way with a small grinder or find any number of methods to lock them together.

In my case I decided to do a quick tack weld to hold it in place, but if you don't have a welder I'm sure it can still be done. I was thinking of grinding a simple key by filing down one half of the crank face, then filing down the opposite half of the shaft face, so that when they fit together they locked the rotation.

Regardless of method, the first step is to align the crank on the shaft in the right position for the parked motor.

You will have to use the original 240 motor crank arm, and bore the hole out to 8mm using a drill.

You then have to park the motor. Wire it up as described earlier, then turn the ignition on, switch the motor on and off at the stalk, allowing it to come to rest. Then remove the key from the ignition.

Go into the passenger footwell and bolt the crank on tight, pointing horizontally at the 9-o-clock position, pointing towards the near side of the car. You will need a fairly short (15mm or so) M8 bolt to hold it in place onto the connector nut. You'll know it's in the right position as you can temporarily fit the wiper linkage onto the crank in the parked position and the wiper blades will be in the correct parked position on the screen.

Once it's bolted in, you can then carefully wiggle the whole assembly back out through the bulkhead hole without removing the crank.



As mentioned I simply tack welded the crank in the correct location, but there are alternatives if you lack a welder.



And that's pretty much all there is to it. You just need to bolt it back onto the car, clip in the wiper linkages as per the 240 motor, and you are all set.

I finished mine off with a bit of heatshrink wrap on the wiring to make it neater.



As you can see here the wipers are significantly faster, with no noise whatsoever.

[YOUTUBE]https://youtu.be/R6ox3PyTxsw[/YOUTUBE]

Compare that to the original motor I was using.

[YOUTUBE]https://www.youtube.com/watch?v=fmwPedjFJ3U&t=4s[/YOUTUBE]

Hopefully this helps someone improve or repair their 240 for very little cost.

[Othen]

Excellent project.

[Moomoo]

Brilliant!👍🧐

[Steve 940]

What an excellent upgrade, and cheap too.

Cheers
Steve

[Juular]

Originally Posted by Steve 940

What an excellent upgrade, and cheap too.

Cheers
Steve

I highly recommend it even if your motor is working, the difference is night and day.

[Big 240]

Lovely job.

Something I may tackle once the weather gets warmer and I get to grips with the MIG.

[Bugjam1999]

Nice one- will definitely add that to the to-do list

Cheers