Amp Research Power Steps and OBD

[bfr57]

Have my eyes on a used set of these power steps that look like I can make work with customizing. However they’re listed as OBDII plug-in. What’s that about? Just for steps? Can it be bypassed?

[truckster]

There's a long thread here:

http://www.67-72chevytrucks.com/vboa...ight=powerstep

[bfr57]

Thanks. Saw that thread in my research but they don’t address the OBDII connection and if it can be bypassed or eliminated to use just the door activated switch.

[truckster]

See posts # 47 and #55.

[bfr57]

Again thanks, but those posts don’t answer my question. It just says he bought a non-OBD boards.

[Richard]

Have modified a non-obd set for my 1994, installed a set of obd triggered on a 2020 Chevy and purchased a new pair of non-obd Ford boards to modify and install on my 1972. The obd triggered set comes with the obd module that connects to two wires in the AMP harness of the same color. Non obd harness just has L/R F/R wires that go to door pins that ground when door is open. Believe the controller module is the same in both cases as current replacement modules indicate they replace all older versions, no mention of obd.

I am pretty sure the difference is the wiring into the connector at control module. If you can get pictures of the connectors that go into the controller on the set you are looking at I can compare to the harness on my 94 and the new harness I have for the 72. Amp will not help at all with any modification or change to the existing parts. There are replacement harnesses available, so maybe that would be the easiest route. Get a part number for a non obd pair (I can give you one) and order the replacement harness. It will have wires located in the correct pinouts. Then again, if you can compare the two different harnesses. You may be able to move the existing two obd wires to the ground trigger locations in connector.

[RichardJ]

I don't have power running boards, but I was looking into them a few years ago when I was looking to buy a new Ram. I never could find anyone that made a bolt-on power step for single cab, 2dr trucks. The 3500 SLT that I bought, sits high enough the factory fixed running board is a perfect door stop for car doors parking next to me.


It seems the OBDII connection uses the "Door Ajar" feature to signal the power step.

I was looking at Rough Country. They use FOUR motors and no OBDII plug-in.
Sensors are adhered to the door frame and a magnet is adhered to the door. The only electrical connection to the truck is 12V and ground.
The AMP uses only one motor on each runner and the price is higher.
I never looked at fitting any of the steps on my '67.

https://www.roughcountry.com/product...steps-psr51920

[Richard]

Originally Posted by RichardJ

It seems the OBDII connection uses the "Door Ajar" feature to signal the power step.

That makes sense. Most likely a L/R signal available. I wonder if the AMP OBDII module is basically self contained. There are only two external wires on it, gets power, ground and information from the car connector. If it sees the left door ajar it would ground one wire and if the right door is open the other wire would be grounded. May be no need to re-pin the controller connector. Easy way to check is ground one or both of the wires going to the controller from obd connection.

[bfr57]

Thanks for the assist! So the steps I found are off a ‘18 Ford Expedition; no controller or harness. Pics are the wiring diagram and controller. It looks like I could just wire the harness into door switches where it’s labeled “posi-splice” and eliminate obd. Would have to make a parallel ckt for other door switch. Or maybe use a harness from a non-obd steps? Thoughts?

[Richard]

Originally Posted by bfr57

Thanks for the assist! So the steps I found are off a ‘18 Ford Expedition; no controller or harness. Pics are the wiring diagram and controller. It looks like I could just wire the harness into door switches where it’s labeled “posi-splice” and eliminate obd. Would have to make a parallel ckt for other door switch. Or maybe use a harness from a non-obd steps? Thoughts?

Not 100% certain but I believe that is the case. Tried to explain more in my previous post. No parallel circuit needed. Only one wire to each door pin. The L/R door pins are on one common circuit in these older trucks so both boards will deploy no matter which door is open. You could use diodes that are provided in original kit (think they sell separate) or isolate the door switches in another way to keep the steps independent to the doors.

[RichardJ]

>>It looks like I could just wire the harness into door switches where it’s labeled “posi-splice” and eliminate obd.<<

Those two wires connecting the OBDII plug to the AMP Controller are probably sending a digital signal.
Todays vehicles can have a dozen or more controller modules. The modules talk to each other and to the ECM through Network communication lines.

[Richard]

How the obd vs door switch version works is kind of a moot point in your situation. You need a controller and a harness. Just order the replacement controller and harness for the door trigger version. After seeing information posted here, I think the obd module just provides two switch to ground wires taking the place of the door pins.
Thinking designing controllers with both functions would be more costly, easier to just supply an add on module that works with the existing standard function controller.

[RichardJ]

>>door trigger version.<<

What other version?
Where have you seen any info on any AMP power step for vehicles before 1998 ?
AMP sells the wire harnesses, but every one says (OBD Port NOT included). They want you to punch a small hole in a plastic plug in the floor and feed the OBD wires through and then attach the OBD plug. The plug is too big to be attached to the harness before installation.
AMP sells the OBD plug if you need that, but they do not sell door switches or magnetic pick-ups or any other way to tell the controller a door is open.
I only see one controller. There is reference to an older controller, but any link takes you right back to the new replacement.

Please provide a link to any other AMP operational system or version. I couldn't find it.
Aries and Rough Country, both use magnetic sensors.

[Richard]

Originally Posted by RichardJ

>>door trigger version.<<

What other version?
Where have you seen any info on any AMP power step for vehicles before 1998 ?
AMP sells the wire harnesses, but every one says (OBD Port NOT included). They want you to punch a small hole in a plastic plug in the floor and feed the OBD wires through and then attach the OBD plug. The plug is too big to be attached to the harness before installation.
AMP sells the OBD plug if you need that, but they do not sell door switches or magnetic pick-ups or any other way to tell the controller a door is open.
I only see one controller. There is reference to an older controller, but any link takes you right back to the new replacement.

Please provide a link to any other AMP operational system or version. I couldn't find it.
Aries and Rough Country, both use magnetic sensors.

As you had said, I believe there is one version of the controller. Though, there may be another as the replacement states some AMP systems it is not a replacement for. My swag is that those vehicles are +12v trigger and not ground trigger.
I have installed a pair with the OBD module. You feed two wires from harness into the cabin, connect to the two wires coming from AMP obd module color to color. As I said earlier, I think the wires from harness are the standard trigger wires and the obd accessory module provides the switching to ground. On a standard installation those wires from harness go to the L/R door pin circuit which grounds when door is open. One wire to each door. The circuit is completed to ground.
It was a couple of years ago but I do not remember a plug to attach the wires together. IIRC used bullet connectors so module could be disconnected and put aside if necessary. The only "plug" is the module which plugs into the vehicles obd port.
What I evidently did not convey correctly is I believe the control module does not receive any sort of digital signal. You had said the wires "are probably a digital signal" If they are then the harness would have to pinned different than a standard harness (different version).
I cannot access any wiring diagrams and would need a set of boards ordered with the obd option in hand to compare and test the components to completely confirm my speculations.
I had said the easiest (also safest) route for the OP is to order a harness and controller for a set of boards that does not use obd control.
Reading your replies helped me think more about how the system is controlled.
Just trying to help a member here.