wire identification ?

[jpattt24]

Hi all, these three wires are on the harness that comes out the firewall under the hood on the drivers side. i am wanting to take out my after market gauges and hook my stock gauges back up. and i came across these three wires. i cannot find the 2 sending unit wires for the oil and temp gauge or the amp gauge. i am geussing there cut or pulled back under the dash. (not sure where they come out the firewall) can i just run new wires from the back of the oil and temp gauge to the senders ? thanks for any help jp

[jpattt24]

[jpattt24]

[70_F100]

The third picture looks like backup light switch wiring.

[fordman]

you are looking in the wrong place. the sender unit wires come throguh the center of the firewall. behind the enigne. follow the sender wires back from the sending units. oil and water. the alt goes throught the passenger side. the wires you are showing are for
1 brakes turns and tail lights as well as aux fuel sending unit wires.
2 windshield washer motor
3 back up light switch for a manual transmission or part of the back light by pass wire for automatic transmnission.

[jpattt24]

thanks for the replys. one more ? the brake warning light to the left of the headlight switch. it is supose to only come on when the key is on (to let you know its working). and when the the brake pressure is low right ? is there a light to let you know the emergency brake is pressed ?

[Calfdemon]

As far as I have heard, the brake warning light is supposed to come on for a second when you start the car (to see that it is working) and then it comes on when the brake pressure is low. It does not function as an emergency brake light. There was a dealer option for that, but it is not that light.

Now, that being said, my brake light never comes on when I start my truck and I have replaced the bulb, so if someone can actually confirm that the light is supposed to briefly light when you start the truck, then I will start troubleshooting my light as well.

[ForingaMex]

Yes, the light is supposed to briefly come on when you start the truck. If the wire-plug is not connected to the switch on the distribution block, than the light won't work. Just one thing to look at if you say the bulb is good. I'm going to hook my light up to the emergency brake as well as low brake fluid warning switch on the Master Cylinder. My MC is from a late 80s-early 90s F150.

[jpattt24]

my brake light comes on when the key is turned to on but does not go out when i start the truck as it should. ? truck was converted to p/s and has the proper portioning valve and the wires are hooked up though. but light is on constant when running.

[fordman]

then the valve is out of adjustment.

[jpattt24]

do you mean the brake valve ? how do i ajust it ? reverse wire was correct i now have reverse lights hooked up to my t-5 tranny! thanks guys!

[jpattt24]

http://cgi.ebay.com/ebaymotors/ws/eBayI ... 0504652393 thanks your right i was looking in the wrong place. where the gauge harness comes out the fire wall someone cut the wires. there is just a rubber plug there now. i purchased a new gauge harness on ebay. and bought the correct oil and water sending units at napa auto today. so i hope to have the aftermarket gauges out from under my dash. i just want a cleaner look inside my truck.

you are looking in the wrong place. the sender unit wires come throguh the center of the firewall. behind the follow the sender wires back from the sending units. oil and water. the alt goes throught the passenger side. the wires you are showing are for
1 brakes turns and tail lights as well as aux fuel sending unit wires.
2 windshield washer motor
3 back up light switch for a manual transmission or part of the back light by pass wire for automatic transmnission.

[ForingaMex]

I don't blame you for wanting a cleaner look in your truck. I personally realy dislike gauges hung from under the dash. The stock gauges just aren't very accurate in these old trucks though. Good luck on figuring it all out.

[jpattt24]

i looked on the net and could not find much on the harness for the 67 f100 so i went to ebay and found it. i also bought the alternator to regulator harness from them. Mr Mustang in ohio.

[jpattt24]

any ideas how to ajust it ?

then the valve is out of adjustment.