Technical Power Steering and Subwoofer

[Acemelon]

I’m kinda just thinking out loud, but.... 03 Punto Active Sport.
I’ve had the Power steering light come on a couple of times. Once in city traffic and once on the open road. Pull over, switch off and all is well again.
I’ve read most of the threads. And I haven’t found one mentioning ICE.
Could the Sub be killing my power steering? It’s not a monster, 300w RMS with an oversize amp to prevent clipping.
Tia
Al

 

[nitramtpr]

It is possible, if the sub is drawing more power than the battery / alternator can support.

 

[Brendan W]

Power steering is a big load on the system. The fuse is rated at 60A and at least one member here has measured 90A. Compare this to the alternator rating and you can see how reliant the system is on a healthy battery especially at high steering inputs at low engine speed.
If the problem is voltage it should be worse just after starting when un-parking. Try a few full lock moves forward and reverse with and without the amp on.
Another common fault is the relays in the motor burn out. They are about a tenner a pair on ebay and a few hours work if you're handy with a soldering iron. Around 03 the motors changed to a solid state type and the motors are not interchangeable. The later motors do not suffer from this fault. This kind of fault could happen when driving in a straight line whereas the battery type fault should not as the alternator is now at full chat. If however a big amp is pulling 20A that could be a different matter.
Before EPS some of these cars were delivered with battery ratings in the high twenties. With EPS they moved up to the thirties. Some here have gone as high as 50Ah to deal with dropping voltage.
Don't rush to blame the battery. If the charging system is not making 14.2 Volts =/- at the battery terminals at 2000 rpm it could be the fault of the alternator or resistive drops on the positive or negative lines to and from the battery. With load on check the voltage drops from the battery positive to the main alternator post and from the alternator case to the battery negative. A tenth of a volt ideally. Check for AC ripple across the battery. There should be almost nothing. Anything more than half a volt coupled with low charging voltage could indicate a leg of the rectifier has blown a diode.

 

[Ziggy122]

I find when im towing i suffer more with power steering cut outs....
Usually cause im now powering extra lights
Stereos on - lights - subwoofer (stock 100w) - and shunting back and forth kills the voltage quickly.....

Ive got a bigger battery fitted - as it was free and in perfect health and i still get droo outs

The voltage drops cause the sensors in the coloumn to misread - throwing codes that aint true....

Ziggy

 

[AndyRKett]

Could the Sub be killing my power steering? It’s not a monster, 300w RMS with an oversize amp to prevent clipping.

could almost certainly cause a problem 300w at its peak is a massive drain on the battery, also these cars are getting old and have well-documented power steering problems, you could just as easily find its a dying power steering motor or battery as well.