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Old 04-28-2012, 02:42 AM   #11 (permalink)
EcoModding Lurker
Join Date: Apr 2012
Location: United Kingdom
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This is my understanding on how these steering columns work.

They are fed by a fairly hefty power wire and earth,and fused with a 60A fuse. They have an ecu with a wire from a speed sensor and a wire from the rev counter plus a fused 3A live and a small earth. The speed sensor varies the amount of assistance. The rev counter wire just tells the ecu the engine is running(I assume so it doesn't drain the battery without the engine running). That's how it works when in the original vehicle.

The controller is just an adjustable potentiometer for the speed signal to vary the assistance.

The system has 3 maps, map 1 is the lowest amount of assistance. When the main power wire is connected without the speed sensor wire the motor works at map 1.

Many people install a 40A fuse as they do not have to turn it up high enough to blow it.

I would assume at its lowest setting(map 1) it would use little power, and would assume a lot less effort than driving a hydraulic pump etc.

Weight wise the column is fairly heavy, but if you stripped your hydraulic stuff out I reckon there may be a weight saving, certainly there would be on an old VW van with the engine in the back! I stripped and weighed my Skyline rear power steering system a few years ago. It had a double pump, one part for front steering, one part for rear. I machined the pump to make it into a front only system and removed half the pump, the lines, and replaced the rear rack with a bar. It all weighed 27KG!

At a guess I would say this system uses an average of 20A at normal driving(nothing when going straight!), so I would say it probably would save fuel. As my van has no power steering I will let you know if I see an increase in fuel use, the trouble is I am also installing a 150A alternator(this may confuse things) as the van has a large stereo(its a party bus!).

I have pics of column if I can work out how to post them.


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