Hi, i've got an SDI estate on a 53 plate. i've noticed a rather strange problem on braking insomuch that the power steering appears to stop working and the steering goes heavy. I dont believe its mechanical and think there is a connection between the sensing systems. Over the last few winters the steering light kept staying on after start up, especialy in the cold. I do my own repairs but this i think may be some obscure system glitch for which i dont have the gear to check or test. Any advise???

This might sound off the wall, but do a battery load test. When you brake, the engine is on over-run, and the alternator clutch slips, so you're reliant on battery power to drive the electric motor that pumps the PAS hydraulic fluid.

Also, check if your battery light comes on when you turn on the ignition.

Also, check if your battery light comes on when you turn on the ignition.

You thinking "broken load sense wire"? I wasn't on the assumption that this had been ongoing for a while and the OP hadn't reported any "flat battery" symptoms.

You thinking "broken load sense wire"? I wasn't on the assumption that this had been ongoing for a while and the OP hadn't reported any "flat battery" symptoms.

I had both wires broken and never had a flat battery. The battery starts to charge if you rev the car over 2500rpm and will continue to charge then too. 

I had both wires broken and never had a flat battery. The battery starts to charge if you rev the car over 2500rpm and will continue to charge then too. 

That's helpful (with an SDi like the OP has) and not well documented. It's not so useful with TDis because 2500 in top is above the NSL.

That's helpful (with an SDi like the OP has) and not well documented. It's not so useful with TDis because 2500 in top is above the NSL.

If you let the car idle after revving to 2500, the alternator will continue to pump out ~14v. The lights will still dim if you turn the wheel at a stand-still but not as noticeably.

You thinking "broken load sense wire"? I wasn't on the assumption that this had been ongoing for a while and the OP hadn't reported any "flat battery" symptoms.

I wasn't, I was thinking broken blue/exciter wire, which is the one that actually helps the alt start, and results in the battery light not coming on, but I know what you mean; there seems to be widespread confusion on here and beyond about which wire does what.

As above, the alt may start producing current on its own (and then continue happily self-supplying the field current) without this wire being intact, but it's not anywhere near as reliable without that initial 'kick'.

Edited 5 August, 20169 yr by Wino

Is it heavy or does the light appear? If the light does not appear check the fluid level. I've seen cases like this breaking and during roundabouts turning to be low power steering fluid.

 

If you have low power steering fluid check for leaks, if you don't have leaks just top up with G004 000M2

 

Hi, i've got an SDI estate on a 53 plate. i've noticed a rather strange problem on braking insomuch that the power steering appears to stop working and the steering goes heavy. I dont believe its mechanical and think there is a connection between the sensing systems. Over the last few winters the steering light kept staying on after start up, especialy in the cold. I do my own repairs but this i think may be some obscure system glitch for which i dont have the gear to check or test. Any advise???

Edited 5 August, 20169 yr by dm222