Upfitter switch power problem

[Towerhog]

I remember reading sometime last year that a member here had a problem with one of his AUX switches. Turns out he had to replace the AUX switch panel to get it to work. You can get one off ebay for around $70.

New 4 Panel Spare Accessory Switch Ford F150 Raptor Super Duty AL3Z 13D730 AA | eBay

 

[PCDan]

Each relay uses four wires; two for the accessory power and two for the trigger circuit. The exact relay terminal numbers may be different between the image above and your truck, but the principle is the same.

Terminal 87 would go to your accessory/lights.
Terminal 86 would be switched (trigger) from the upfitter switch.
Terminal 30 is supply to the relay that passes through to the accessory when the upfitter/trigger is switched.
Terminal 85 is the ground side of the trigger/upfitter.

It sounds like you have a bad relay or a bad 'terminal 87' circuit in your truck.

I swapped each of the relays in the box off the drivers side firewall to the AUX1 relay that is hooked to 10 forward duallys. All of the relays worked at position 1 so I think the relay is good.

Is the terminal 87 circuit just the wire from the relay to the hot supply behind the glove box?

Thanks for the help, sorry Im not an electrician.

D

 

[BAJASVT]

Is the terminal 87 circuit just the wire from the relay to the hot supply behind the glove box?

Yes.

Also, check to see if you can hear the relays for AUX 2, 3, & 4 click when the corresponding aux switches are flipped. If you can hear/feel 2 & 4 click, but not 3, then you'll know your problem is on the trigger side of the relay. If you can hear/feel aux 3 relay click, then the problem is in the wire between the relay box and the wire behind the glove box.

I'd double and triple check that you have the correct wire behind the glove box even though it sounds like you do.

 

[PCDan]

Yes.

Also, check to see if you can hear the relays for AUX 2, 3, & 4 click when the corresponding aux switches are flipped. If you can hear/feel 2 & 4 click, but not 3, then you'll know your problem is on the trigger side of the relay. If you can hear/feel aux 3 relay click, then the problem is in the wire between the relay box and the wire behind the glove box.

I'd double and triple check that you have the correct wire behind the glove box even though it sounds like you do.

Ok, I will do that, but I am going to meter the relay box connections again today. Yesterday When the AUX3 relay is switched ON the second (middle) large post connection and one of the small posts connections go hot. With the switch off only one large post is HOT. The other relays (1,2,4) connections in the box are hot at the one large outside post when switched OFF, and then one of the small posts also goes hot when the switch is turned ON. The middle large post only goes hot when switched on at the relay 3 position?

 

[BAJASVT]

You're talking about the relay socket, not the relay itself, correct?

With the relay removed, socket #30 should be hot at all times (or at least with the key on). Socket #86 should go hot when the corresponding aux switch is toggled on and the key is on. Socket #87 should also go hot when the corresponding aux switch is toggled on, but only if the relay is installed in the socket.

You can pop the plastic cover off the relay and verify this is operating with the relay installed.

The middle large post only goes hot when switched on at the relay 3 position?

Would this be socket #87A?

 

[PCDan]

So as it turns out I needed to actually quadruple check the wiring. The original diagram I was looking at had the wrong color codes for the wires, but I was still a dork and should have metered all of the wires under the dash first. Problem solved ... had two hot supply wires connected. Thanks for the help though, the good thing is I now know exactly how the AUX switching wiring runs through the fuse box and relays HA

 

[Rookie]

lol. Shit happens. Glad you figured it out

 

[SVT Guy]

I did the same thing but cuaght it instantly. It happens for sure!

 

[DonStriker]

I need help identifying which fuse blew... how did you figure out 44 for yours? My Aux 3 light works but the accessory I wired to it (using the pass through for either 3 or 4, can't remember which) stopped working when the KC lamps warmed up... There are a lot of "not used" 15a and 10a in the darn manual, which does not tell you hot the upfitter is fused.