2015 PIU Aux buttons

[Eric Z]

If I understand correctly, the Aux switches on the steering wheel were set up to control various light options. I assume those switches were just used to activate relays that pulled in the high amp loads? Any idea as to what fuse locations were for what switch?? In other words, how does one figure out what power lead or location is energized by what switch? Would be neat to use those switches again, but there is a ton of wiring to trace......

 

[billyfromhill]

See the upfitter manual. The four aux switches control switched grounds in the 16 pin vehicle signals harness under the center of the dash. The wire controls the ground side of the coil of a normal Bosch style automotive relay. DO NOT connect the ground side of you loads to the wires.

AUX Button Light Wiring

 

[Trader0000]

There are no fuses for the aux buttons. They are controlled by a computer module.

 

[Eric Z]

See the upfitter manual. The four aux switches control switched grounds in the 16 pin vehicle signals harness under the center of the dash. The wire controls the ground side of the coil of a normal Bosch style automotive relay. DO NOT connect the ground side of you loads to the wires.

AUX Button Light Wiring

Ok thanks for the info. I find the info and think I know the connector in question and the table shows me pin and wire info, but.... Can you explain in more simple terms the power situation?? I had thought I would see +12volts at the connector pin, when that aux button was "on". I would then use that 12volts to activate a separate relay, but????? If I understand you... What I need is a "Bosch" style relay. To that I run a fused (at whatever level I need) power feed, to a power input on the relay and the power out goes to my load (lights). From the connector pin I run wire to the ground side of the relay and the lights have their own ground??

 

[Trader0000]

Yes, the AUX is part of the relay control circuit and you run your load (lights) with the power circuit side of the relay. The lights use their own separate positive source and ground.
The AUX wire from the 14 pin connector completes the relay coil circuit.

 

[billyfromhill]

Ok thanks for the info. I find the info and think I know the connector in question and the table shows me pin and wire info, but.... Can you explain in more simple terms the power situation?? I had thought I would see +12volts at the connector pin, when that aux button was "on". I would then use that 12volts to activate a separate relay, but????? If I understand you... What I need is a "Bosch" style relay. To that I run a fused (at whatever level I need) power feed, to a power input on the relay and the power out goes to my load (lights). From the connector pin I run wire to the ground side of the relay and the lights have their own ground??

When an AUX switch is off, you will have no signal on the wire. When an AUX switch is on, the wire corresponding to the switch is ground. If you test with a multimeter you should have continuity to ground when the AUX switches are on.

A Bosch style relay is just a standard automotive SPST/SPDT relay.

You would connect the AUX wire to pin 85 of the relay and B+ to pin 86. Your B+ for the load goes to pin 30 and your load connects to pin 87.

GY-BN is one of the AUX switch wires in the 14 pin vehicle signals connector in this example.

 

[Eric Z]

When an AUX switch is off, you will have no signal on the wire. When an AUX switch is on, the wire corresponding to the switch is ground. If you test with a multimeter you should have continuity to ground when the AUX switches are on.

A Bosch style relay is just a standard automotive SPST/SPDT relay.

You would connect the AUX wire to pin 85 of the relay and B+ to pin 86. Your B+ for the load goes to pin 30 and your load connects to pin 87.

GY-BN is one of the AUX switch wires in the 14 pin vehicle signals connector in this example.

Thanks that helps clarify the wiring and I will post again when I get it all wired up. Nice to have people who can interpret the Ford Modifiers guide.

 

[Steven K]

Hey, any updates on the wiring?

 

[Eric Z]

Hey, any updates on the wiring?

I have isolated the connection and wires from the AUX switches and am using one for fog/driving lights, and planning to use another for a 110 volt inverter plug in back, not sure what I will do with the other 2.

 

[Steven K]

Thanks, I have a bunch of wires that I assume used to be connected to radios maybe that come out under the floor behind the second row. There's a bunch of regular looking harnesses and a 6.5mm audio cable that I don't know where any of them run to. Any ideas for what to do with those?

 

[Eric Z]

Thanks, I have a bunch of wires that I assume used to be connected to radios maybe that come out under the floor behind the second row. There's a bunch of regular looking harnesses and a 6.5mm audio cable that I don't know where any of them run to. Any ideas for what to do with those?

That is where I found many of mine, from under the floor console. Be careful with those wires, as I found mine had just been cut, but most were still live. If not being used, at least isolate and insulate them to avoid sparks and fires. The Upfitter Guide referred to above is VERY helpful.

 

[kobresia]

I'm curious, is the Aux switching only available with SYNC? I've been deducing as-built differences between my PIU and a wreck I bought. The wreck is equipped with SYNC, it has the Aux buttons on the steering wheel and a host of peripheral modules and accompanying wiring which rely on the SYNC APIM. My PIU was not equipped with SYNC, its steering wheel only has the basic media buttons on the right spoke.

I figured-out which changes needed to be made to the IPC to get the Aux display while chasing something else, so I have that now rather than the useless illustration of an SUV in the instrument cluster. I'm assuming that it's also useless without further modifications, but at least it looks less stupid.

Do I need to keep hunting for differences, such as a change to the BCM enabling that? Or, is the APIM from the SYNC system and its wiring harness is required for the Aux functionality? I haven't dug into the wiring behind my radio console to see if I even have the Aux control wires, but I'm guessing it may all be missing since it probably would've been enabled if it was functional.

It'll probably all be moot at some point in the not-too-distant future. As soon as I get the dash wiring harness out of the wreck intact, there's a very good chance I'll try to rewire my PIU up to SYNC, but it'd be really nice to know what's possible for folks who aren't inclined to undertake such a ridiculous modification.

 

[kobresia]

Thanks, I have a bunch of wires that I assume used to be connected to radios maybe that come out under the floor behind the second row. There's a bunch of regular looking harnesses and a 6.5mm audio cable that I don't know where any of them run to. Any ideas for what to do with those?

The 6.5mm audio jack & cable seems to be fairly common for connecting a PA mic to a remote siren controller. Most of the power for a rear equipment tray would come from the rear power point, which is behind the side panel rear of the right rear door. Red wires going forward would probably be to take power to a radio console, most of the other wires are probably remnants of inputs from controls or outputs to lightheads and other devices. There's a very good chance at least one pair of wires goes to the horn button for "hands-free" siren tone changes, if that wasn't undone properly during decommissioning, that could be trouble.

Your best bet would be to check voltages on all the wires, and if you have any live wires coming off that power point, take off the panel and disconnect them at the source. The OEM wiring harnesses should be pretty safe if they have the original plastic connectors, but I taped over unused connectors anyway. If you have random cut wire ends everywhere, that's when you want to make certain nothing has power, and just terminate all the ends safely anyway. Almost all of that factory-provided wiring harness still connects somewhere in the vehicle, whether to modules or empty plugs behind the grille.

 

[Eric Z]

I think the Aux switches serve different functions on the PIU and SYNC.... Volume controls and station advance in SYNC. A couple of the wires in that same AUX plug that went from under dash all the way into the back were 40 Amp, so making sure those are not left live is important. Disconnect the plugs is best and that is at front of console in lower dash.

 

[kobresia]

I think the Aux switches serve different functions on the PIU and SYNC.... Volume controls and station advance in SYNC. A couple of the wires in that same AUX plug that went from under dash all the way into the back were 40 Amp, so making sure those are not left live is important. Disconnect the plugs is best and that is at front of console in lower dash.

To clarify, the wreck is also a PIU, it's just one which had been ordered with SYNC. My non-SYNC PIU did not have Aux enabled or the numbered buttons on the right spoke, that's why I was wondering; it has the volume and media controls instead.

PIUs with SYNC don't seem to be very common, so I'm guessing there's a way to get it enabled without SYNC. Hopefully, it wasn't another option that has a special wiring harness and all.