Mystery black box

[Warrennc]

This box has one on off switch, a 6 position rotary knob and only two wires coming out of the box, one black and one red. The red one disappears through the firewall.
I have messed with it and have no idea what it does.
Anyone have any suggestions on to what it was intended for?
It is attached to the center console using Velcro tape. A little searching has revealed that I have no idea where the red wire actually goes.

[Tuscany]

My guess would be a remote on off switch and gain control for an amplifier.

[Warrennc]

Originally Posted by Tuscany

My guess would be a remote on off switch and gain control for an amplifier.

Well, with only two wires. That is a possibility. But that doesn't explane the definite 6 postings for the rotary switch or maybe it is just a variable resistor with 6 positions maybe? If it is for an old amp. The amp is long gone.

Your guess is about the best so far.

Any chance maybe it has something to do with a mod to the powerstroke Diesel engine that may no longer exist? Not enough wires for a 6 position chip and it seems to have no effect on the engine.

[Tuscany]

I doubt it was for any performance related things unless it was a remote for a 6 position chip maybe??

[Warrennc]

Originally Posted by Tuscany

I doubt it was for any performance related things unless it was a remote for a 6 position chip maybe??

That is what I though but not enough wires and if it is...the chip is long gone or the control is not working. Maybe later, next Saturday, I may have to crawl under the truck and see if I can trace that wire and see where it goes.

Even with the mystery problems. This truck is amazing. Traded an old suburban for it. So far, having a blast with the new to me truck.
My first ford truck. Would love to figure out all those non working systems and fix em. Found two KC switches but no aux driving lights. Just got some pilot navigators to mound where the ole KC lights were. But I drift to other problems for other threads.

Thanks for your suggestions.

[Diesel_brad]

Tracing the red wire to see where it goes would be the easiest

[Warrennc]

Originally Posted by Diesel_brad

Tracing the red wire to see where it goes would be the easiest

That is the plan. But easier said than done. It passed through the firewall at a hard to get to spot. Can't see it and the ford is lower to the ground than my old suburban. Can't get under there with my old creeper. May have to just forgo the creeper and drag my old fat axx under there and see if I can see it from below.

Got a few other circuits to look over to keep me busy.

Again, thanks for your suggestions. Will keep em in mind as I look for the end of that wire.

[BigFuel]

See if it comes back and tags into the purple wire in the PCM harness (next to the brake MC) Don't know what the dial is for but a two pos rocker switch could mean TC override or a EBPV override.

[Warrennc]

Trackng the wire is not easy. it passes through the firewall into the engine compartment where i cant see it....yet. Haven't squeezed my fat ars under there yet. But I will see if I can locate a purple wire and see if it has another wire tapped into it.

it is not a torque converter override due to i have a 5 speed standard transmission. If my memory serves me correctly, a manual or standard trans does not have a torque converter.

As for the other, EBPV override. Possible.
Assuming it is a EBPV override.
What should I notice with on versus off on that switch.
When does the Exhaust back pressure valve normally operate and...from what I have found, helps the engine warm up when cold. Is that correct?
Will there be a sound difference in the engine when cold or hot? power difference when cold or when hot? Etc....

I'm a newbie to Diesel engines. Reason for my many questions.


Thanks BigFuel.

[BigFuel]

No worries. People have converted the EBPV into exhaust brakes by overriding the neg. side of the solenoid wiring. At idle you wouldn't notice it but if you where driving down the road you'd notice an instant drop in power as the exhaust is now closed off. It's a neat mod if you mind the downsides.