HELP my F150 lights will not turn off - Ford Forums

cbence · 10-26-2003, 10:48

I would like any help I can get on a preplexing problem. First, after turning on my headlights, then turning them completely off, the headlights go off, but my front parking lights, tail lights and instrument lights stay on. After I removed my battery cable, of course they went off. I reconnected the battery cable and they lights stayed off.

I turned the lights off, then on and removed the light switch completely and the lights still stayed on. I hooked up my test lamp and there was power to the parking light-tail light circuit. I disconnected the battery cable and the lights went off.

I then straight wired the parking light-tail light circuit to the hot wire in the socket (with switch removed) and the lights came on. I broke the circuit and the lights stayed on.

Anyone have any idea how there is power to the circuit with the switch removed?? The wiring diagram shows the hot wire running from the light to the light switch, but it appears the circuit is getting power from another source.

Thanks,

Chuck

351w · 10-26-2003, 16:24

what your describing with the lights staying on after you break the circuit that energizes them tells me that they are not directly powered through the switch they are receiving power through a relay and when you turn on the light switch or directly wire it to a power source you are only energizing the coil of the relay.
i would think that by your description either the relay is sticking or their might even be a timer in the circuit but you failed to include the yr of you particular f-150.
i have to assume since you are requiring info on this matter that the lights do not turn themselves off after a short period of time.

cbence · 10-26-2003, 19:37

Thanks 351,

Mine is a 1991 F150 ex cab. Has been a great vehicle. Just had it painted, but have had no mechanical problems whatsoever and it has 120k miles.

As to my problem, I found a reference to a relay in the wiring diagram in my Haynes manual. I too, had about decided that was about all it could be. In effect, the contacts in the relay were not releasing when the switch was turned off. No, they would not go off after a short while. In fact they ran my battery down, because I did not notice they were left on. I did not notice they were on as I had them on during the day during a rain shower.

I will pick up a new relay tomorrow. Hoping this will solve the problem. If not, I will get back. In fact for everyone's info, I will post the result of replacing the relay.

Thanks again,

Chuck

351w · 10-26-2003, 19:44

ok glad to see were on the same pg and i was pretty sure it was a relay problem but what seemed funny to me was the fact that it went off when you unhooked the battery and the reconnected it.
i have seen similar problems with driving lights before that acted almost identically to what you described.

cbence · 10-27-2003, 21:07

A new relay fixed the problem.

Thanks, 351w!!

Chuck

89F150 · 10-27-2003, 21:17

Any pics of your truck?

351w · 10-27-2003, 22:26

Quote:

Originally Posted by 89F150

Any pics of your truck?

is that the only thing you know how to say ?

glad to hear that somebody around here appreciates me !
your welcome chuck.

89F150 · 10-27-2003, 22:35

I like pictures. A picture is worth a thousand words,