1998 Explorer - 12V modified outlet losing power when A/C turned on

[rmurray]

I recently installed a dashcam in my 1998 Explorer using the 12V outlet on the lower passenger side of the center dash. Because I want the dashcam to turn on and off with the vehicle, I had to add a relay to the outlet using the + and - from the outlet itself. For the power to switch on and off, I tapped the thickest red wire from the bundle of wires in the center console. I used a multimeter to determine that the thick red wire showed 12V only with the keys turned to On. For the most part, it works perfectly, that is until I turn on the A/C. For some reason, the A/C completely cuts power to the outlet. Its not even an interruption, it just completely cuts the power until the A/C is turned off, at which time, power is restored to the outlet. I figured that red wire is either powering the CD changer, or the radio controls at the back of the center console. I plan on checking the relay to see if I can determine where the power is being dropped. Any one ever experience anything like this? Could it be the ground or the outlet fuse? Any suggestions are appreciated.

 

[Rick]

I recently installed a dashcam in my 1998 Explorer using the 12V outlet on the lower passenger side of the center dash. Because I want the dashcam to turn on and off with the vehicle, I had to add a relay to the outlet using the + and - from the outlet itself. For the power to switch on and off, I tapped the thickest red wire from the bundle of wires in the center console. I used a multimeter to determine that the thick red wire showed 12V only with the keys turned to On. For the most part, it works perfectly, that is until I turn on the A/C. For some reason, the A/C completely cuts power to the outlet. Its not even an interruption, it just completely cuts the power until the A/C is turned off, at which time, power is restored to the outlet. I figured that red wire is either powering the CD changer, or the radio controls at the back of the center console. I plan on checking the relay to see if I can determine where the power is being dropped. Any one ever experience anything like this? Could it be the ground or the outlet fuse? Any suggestions are appreciated.

Are there HVAC controls in the console for the rear seats?

 

[Turdle]

There is also a rear blower motor in the center console. But I'm wondering what in that would turn off with ac on. Unless max ac has its own fan power circuit, switching off the blower speed controller also in the center console, mid rear.

Edit
It's much easier to work on the console inner components with console removed.
Or, eliminate the issue, go somewhere else for key on 12. You might look for a power source off the fuse panel , route it through the console pass thru area, to the 12v outlet.

 

[rmurray]

Are there HVAC controls in the console for the rear seats?

There is a fan speed control and a lever for face or feet. MOst of the electronic controls are for audio.

 

[Turdle]

There is a fan speed control and a lever for face or feet. MOst of the electronic controls are for audio.

Rear heat and radio controls on rear of console? Gotta get in back seat to see them.
Edit you answered

 

[Rick]

There is a fan speed control and a lever for face or feet. MOst of the electronic controls are for audio.

Nothing for heat? I was thinking that it turns off power to heat when A/C is on.

 

[rmurray]

There is also a rear blower motor in the center console. But I'm wondering what in that would turn off with ac on. Unless max ac has its own fan power circuit, switching off the blower speed controller also in the center console, mid rear.

Edit
It's much easier to work on the console inner components with console removed.
Or, eliminate the issue, go somewhere else for key on 12. You might look for a power source off the fuse panel , route it through the console pass thru area, to the 12v outlet.

I just checked the relay. With the car running, the battery + wire is showing +13V. The switched power is showing about 10V. When I turn on the A/C or heater or defrost on the dash, the switched power goes down to <1V. The rear controls only somewhat modify the dash controls, so when the front air is on, the rear air is on also, but can be adjusted from low to high speed. It does sound like there is a blower in the center console. Its seems weird that the power would drop though. Is it possible that the blower is causing the drop in power to the relay?

 

[rmurray]

Nothing for heat? I was thinking that it turns off power to heat when A/C is on.

There are no temp controls for rear seats. Only two wheels. One feels like it just opens and closes a vent to direct heat either out of the vents at the top rear (Face) of the console or down (feet) to the floor. The other wheel is fan speed = 1, 2, or 3. The relay loses power regardless of what setting the climate controls are on, heat, A/C, or window defrost. Whether its on full, or low, doesn't matter.

 

[Turdle]

I'm going to suggest there is another large 12 v wire , and you've found the one that switches low, to switch the rear controls on.

 

[rmurray]

I'm going to suggest there is another large 12 v wire , and you've found the one that switches low, to switch the rear controls on.

I will check, but why would a red wire switch from 12V to 0V when something switches on? It just seems odd to me.

 

[Turdle]

That's how some components switch. 12 v on both sides. One side switches low , to 0 volts, creates a potential difference which turns component on. Fuel injectors, for one.

Wiring diagram sure would help here.

 

[Turdle]

Not sure how accurate on line diagrams are.

Are you sure the red wire isn't red-orange stripe?

 

[rmurray]

Not sure how accurate on line diagrams are.

Are you sure the red wire isn't red-orange stripe?

Yes, it is a red wire with an orange stripe. I did not notice it before. What does that mean?

 

[rmurray]

Trying to decipher the wiring diagrams. I made some noted, going to check some wires now.

 

[rmurray]

OK, I found some wiring diagrams and I think I figured it out. Apparently, the red/orange wire does cut power when the climate control is on. So strange. The Pink/White wire was the one I should've been using. Its a smaller gauge wire, so a little harder to make a good connection, but I think I got it. Now it works with the air on too. Thanks everyone for your guidance!