Nice 12v switched ignition wire in engine bay? [Resolved]

[99streetranger]

I am wiring up an electric fan in my 3.0 ranger. I am looking for a nice, easy to splice wire in my engine bay to get the 12v signal from. I need power only when the key is switched on.

 

[RonD]

Assuming it's just for a relay then EGR solenoid, MAF heater, or IAC Valve are OK
MAF heater 12v wire would probably be easiest, in 1999 it would be the Red wire

 

[99streetranger]

I went ahead and tapped into the 12v brake light switch, verified it had ~ 12 volts only with ignition on.

 

[Uncle Gump]

Brake light switches are supplied 12 volt hot at all times. Same as the hazard flashers.

 

[RonD]

+1 ^^^ Brake light switch has 12volt power all the time, on all vehicles
You misread voltage OFF

 

[99streetranger]

The multimeter reads 0 amps and volts with ignition off, but 12 volts with ignition on, might be something other than brake light switch but definitely no power when key off.

 

[RonD]

If the switch has 5 wires then it might be the brake pedal sensor, used for shift interlock, ABS, and cruise, but in 1999 that should have 12v all the time as well

But I thought you want engine bay 12v on/off?

 

[99streetranger]

It has 4 wires and is next to the fuse box. Goes into what looks like a distribution block. Multimeter says it is 12v only with key on.

 

[99streetranger]

For future reference: I ended up using the IAC for the 12v+ signal. No problems whatsoever after around a month of driving with the fan setup.

 

[RonD]

Yes, that is a Key on, engine not ACC, so a good, easy to get at wire, for a Relay