electric rack draw

[woodsman]

OK, this might be the strangest question. How much does the electric steering on our trucks draw? The reason I ask May Be stranger. I have been messin with cars since I was old enough to have one. I am Installing an electric rack on a restomod, they say to have a 100 amp breaker... WHAT? So that got me wondering, if my alternator stops charging will the steering run my battery dead very quickly? If we are on a curvy road with our trucks does it take very much more than straight ahead?
I am excited to do this on my restomod for many reasons, when you turn the key on you have power steering, less clutter under the hood, no PS. fluid leaks, no pump noise, and just plain freaking cool. I will be using a newer Mustang rack. The car is a 62 Mercury Monterey Convertible.

Sponsored

 

[potato]

The steering is a mystery to me too. After decades of living with Ford power steering whine, 2 1/2 years later with this truck I have still not wrapped my head around how silent it is

But yes. I too am curious if it runs off the tiny 12 volt or at high (main battery) voltage.

 

[Maquis]

It runs on 12V. Ford also uses Electric Power-Assisted Steering (EPAS) on ICE vehicles. Not sure what the maximum amp draw is.

 

[Joe Dablock]

I’m guessing (but I really don’t know) that under a severe steering situation (wheel up against a curb and you a pulling with all your mite to turn the wheel, the momentary current draw could get quite high and the circuit is fused for the worst case scenario.

 

[bmwhitetx]

FWIW, my owners manual shows a 10A fuse for EPAS and two 50A fuses for the PSCM. The PSCM is integrated with the EPAS. Service manual shows it this way:

As far as running it off the HV DC bus - if the HV bus trips due to a battery fault while driving, you will still have power steering since the 12V will still be good.

 

[Firn]

These trucks get 12v power from a dc-dc converter that takes the 389v from the main battery and converts it into the 12v.

If that fails will the steering eventually run the battery down? Yes. But so will every other 12v component in the truck, including all the computers, screens, coolant pump, cooling fans, etc.

That said, I believe the gas trucks use the same system so the power draw shouldn't be excessive for a regular engine and alternator.

I have not looked into rack swaps. How does one manage the steering computer?

Sponsored