Convert to electric power steering pump

[kingsway]

I'd like to try an electrical PS pump on my VW Golf.

I just got a nice hefty PS pump on eBay - from a Peugeot 307. Has mounting brackets as well.



Just one problem - the electrical connections are a lot more than just the two power terminals....

There is a multi-way connector - which I assume is used to control the pump. Various speeds according to road-speed?



The only wiring diagram I can find online is not too helpfull, so I may have bitten off more than I can chew!

Peugeot 307 Complete Wiring Diagrams

Can anyone tell me how pumps like this are generally controlled? Are they usually variable speed??

Having looked around on wikipedia, I suspect the Peugeot system can vary the torque available according to the requirements of the Electronic Stability Control system!!! Maybe I should look for something simpler.... ?

TIA

[Frank Lee]

Your car is small. Just take the belt off.

[t vago]

Not sure about that pump, but the Toyota MR2 pump has a pin that receives vehicle speed from a speed sensor. That allows its on-board computer to vary the pump power according to said speed. There's another pin that enables or disables the pump, which is normally controlled by the main engine computer.

Another pin is an output pin that tells the engine computer to raise the power of the engine if it's at idle.

Finally, there's an output pin that goes to a light on the dashboard, which warns the driver if there's a problem with the pump.

Unfortunately, the Peugeot 307 schematics you found do not actually label the wires/pins. That means you have a bit of work ahead of you, decoding what each pin does on your pump.

[t vago]

My guesses are as follows:

Pin 9 - pump enable from engine computer
Pin 1 - speed sensor output
Pin 6 - speed sensor output
Pin 5 - switched ignition power
Pin 4 - warning light
Pin 3 - ???

[kingsway]

Might be more trouble than its worth for just 1 mpg?

I've considered just taking the present pump out of the circuit - but steering becomes extremely heavy when I EOC, so I'm not sure how much better it will be if I just loop the pipes...

[oil pan 4]

Crack it open and hot wire it on.
Just dont run it at full power for long peroids of time, that might burn up the motor.

Looping the lines does help quite a bit with steering boxes, not sure how much it helps with rack and pinion.

[AXMonster]

You need a PS pump for a Saxo VTR, only has the two power wires.
Looked into doing this myself but the PS pumps are too expensive to experiment with. Was going to rig it so that the pump comes on at <25 mph with hysterisis so that it goes off about 30 mph.

[paulgato]

How did you get on with this Kingsway?

I'm thinking of doing it myself on my 2002 TDi PD Golf.

I once had a Vauxhall Astra 1.7D normally aspirated diesel estate car with no turbo and no power steering. It drove really well. It was hard to turn the wheel when the car was stationary, but that's bad for the tyres anyway. The Golf has most definitely heavier steering that the Astra so kind of needs power steering in my view.

(On my last car - a Mk3 Golf - I remember the Power Steering belt snapped and, well, it still drove OK for the day or so until I got the new belt fitted, but at times it felt less than 100% safe to drive. It felt like I couldn't steer out of trouble so quickly. Maybe I would have got used to it.)

I was thinking of a simple on/off switch on the dash for power steering, so I can switch it on when I need it (for parking and so on) but otherwise not use it.

Primarily I'm trying to get rid of the altenator, but if I remove the alternator belt (accessory belt) the power steering won't work either. Hence wanting an electric pump. It should save a bit more fuel too.

[oil pan 4]

Biggest thing you can do to boost MPGs in that non turbo 1.7l diesel is stick a properly sized turbo on it.

[paulgato]

Thanks for the suggestion oil pan 4,

...but the Vauxhall Astra 1.7D Estate (with no turbo, no power steering and no air conditioning) is long gone and no longer my problem. When it developed more rust than I could deal with I gave it to a friend who had it for three or four years and then sold it to someone else locally. She says she still sees it around. It's 23 years old and still going. It was also a very easy engine to work on, with all that space around it in the engine bay. There's merit in simplicity. I got 62mpg (IMP) on long trips and about 55mpg overall. The car I had before that one was the same car (well that was the car-derived van version, but built on the same body shell - just with no seats and windows in the back, but a good comparison) and had the same engine but the turbo version (1.7TD). The fuel economy of that one was about the same as the non-turbo one. Possibly a bit worse overall, but that could have been because it was faster.

For my current car (Golf Mk4 diesel estate) VW quote both my version (100bhp TDi) and the 68bhp non-turbo SDi as having the same fuel efficiency of 5.2l/100km combined, with the 100bhp TDi being very slightly better in the urban cycle but slightly worse on the highway. The other, more powerful TDi versions are all slightly worse on fuel, according to VW.

But the point I was making in this thread was that power steering does not always make a car nicer or easier to drive. It's quite possible to have a heavy diesel engine in the front and still steer it comfortably without p/s. The 1.7TD had power steering and was much harder work to drive than the 1.7D without p/s, except when parking. Large movements of the steering wheel were easier with the p/s but those slight unconscious adjustments that you make when going along a 'straight' road were not - it wouldn't respond easily to tiny pressures on the wheel - and it was a tiring car to drive on motorways, although fine around town.