Rear Light Problem 94 F250
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Rear Light Problem 94 F250
I just bought a 94 F250. The right rear lights dont work(none of them). On the left side i have backup, turn, no running lights or brake light. The cab mounted brake light works fine. From reading other posts and looking at my Haynes book I suspect the Multi-function switch. Is there anything else that I should check before replacing it? I once replaced the wiper motor and multifunction switch on a Taurus, found the problem to be corrosion in the main connector, not the motor, expensive lesson. I am going to check power to the right side light tomorrow before i get too carried away and start replacing switches. I have already checked the fuses in the dash and replaced/installed the correct rated fuses. The ignition switch is going to be replaced since it doesn't work properly.
Last edited by Highpockets658; Sep 16, 2003 at 11:58 PM.
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From: Virginia
Rear Light Problem 94 F250
The running lights do not go through the multi-function switch. So I would concentrate on them, and maybe you will find one problem causing the whole thing. I think its a brown wire that feeds both sides and the license plate light too.
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Rear Light Problem 94 F250
Thanks Dave, the wiring diagram is over my head, I have to do these things by the hunt and hope method!! I planned to do some more checking with my multimeter tomorrow before I get to crazy with the money.
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Rear Light Problem 94 F250
Checked the connector at the rear of the wiring harness today. No power except to the left side. Pulled the multifunction switch and did continuity checks as outlined in my Haynes Manual. 2 tests failed so I guess I will be replacing the switch.
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From: Virginia
Rear Light Problem 94 F250
Look at this diagram:
http://www.cybrrpartspro.com/Chilton.../88286W27L.jpg
Look on the top left side. You will see the headlamp switch. Follow the wire down the left side that is lableled BRN (brown wire). If you follow this brown wire, it goes to all the running/taillamps. And it is a very simple circuit, unlike the brake/turn circuit which is more complicated.
You should have a brown wire coming out of the switch. Check for power here with the light switch pulled half-way out. If you have none, then you may have a fuse problem. If you have power there, then find the brown wire at the back of the truck, and see if you have power there, putting the negative of the meter on a good clean ground on the frame. If you don't have power, then work your way back up along the driver's side frame rail looking for problems.
If you have voltage at the rear, then I would pull the lenses and check there. See if you have power on the brown wire in the socket, with the negative of the meter on the socket ground. If you don't have it, then check the socket brown wire again, only put the negative of the meter on the good ground on the frame that you had before. It may be a grounding problem, you never know.
http://www.cybrrpartspro.com/Chilton.../88286W27L.jpg
Look on the top left side. You will see the headlamp switch. Follow the wire down the left side that is lableled BRN (brown wire). If you follow this brown wire, it goes to all the running/taillamps. And it is a very simple circuit, unlike the brake/turn circuit which is more complicated.
You should have a brown wire coming out of the switch. Check for power here with the light switch pulled half-way out. If you have none, then you may have a fuse problem. If you have power there, then find the brown wire at the back of the truck, and see if you have power there, putting the negative of the meter on a good clean ground on the frame. If you don't have power, then work your way back up along the driver's side frame rail looking for problems.
If you have voltage at the rear, then I would pull the lenses and check there. See if you have power on the brown wire in the socket, with the negative of the meter on the socket ground. If you don't have it, then check the socket brown wire again, only put the negative of the meter on the good ground on the frame that you had before. It may be a grounding problem, you never know.
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