My low beams both went out on my 1997 f 150. High beams work when i pull the turn signal lever in. Checked the fuses and replaced the headlight bulbs and no go. Any thoughts ? Multifunction switch ? Thanks for any and all help.

 

Did you check for power at the bulb connector ?

Next would be to check for power on both sides of both fuses

 

No I have not, but I will. I assume you're referring to the socket, aka bulb connector ? If so, I assume it would be ok if the brights work.

 

Yes the socket / connector are one in the same ( too used to calling things connectors ).

If the brights work, you will have voltage on only 1 of the 2 pins ( the 3rd is ground, which is black ).

The fuses, there are 2 fuses for the low beams ( cab fuse panel fuses 26 & 28 ) and 1 fuse for the high beams ( cab fuse 16 ).

Best to start with turning the headlamps on,and checking on the pin on the back of the fuse ( both sides ) for the low beams. Easier then yanking your headlamp housings out. Make sure you have a good ground when testing, as not to get a false reading.



If these are dead on both sides with the main headlamp switch turned to the head position, and the MFS in the low position, then there is a problem with the MFS, and time to remove and test it.

 

Sorry, threads on the MFS & cleaning it

https://www.f150online.com/forums/el...on-switch.html

https://www.f150online.com/forums/el...r-gremlin.html

The other you would see when taking it out, is a loose connector in the steering wheel column.

Which makes me think of another item, try moving the tilt on your steering wheel all the way down ( try low beams ) and all the way up ( try low beams again ).

This might diagnose the difference between the MFS and the connector.

 

Thanks Sscully. I will use this info tonight to investigate my problem. Will keep you informed

 

Don't forget that you do have two fuses, and two relays that control the HL circuit. The fuses and relays are in your UH-EC Fuse/Relay Box. The MF switch controls the relay coils first.

 

Relays are only with Autolamps

1997 EVTM cell 85-1

 

i have exactly the same problem, 1997 XLT - only high beams. I checked for power at both fuses and I have 12 V at each one - on opposite sides of the fuse - i.e. there is 12 V on the right hand socket on one, 12 V on the left hand on the other. Is that weird - or is that how the fuse box is wired in the back? Anyway, having power there would seem to rule out the switches - so what is left ( no autolamp in this truck)

 

You pulled the fuse to check, or checked the pins on the back of the fuse ?

This is opposite sides of fuse 26 and 28 ?

You high beams, are they with the FTP feature ( flash to pass / pull back on the MFS ) or both FTP and normal operating ( push forward ) ?

If you have power to one side of fuses 26 & 28 with the main headlamp switch turned on, the MFS should be OK, as Fuses 26 & 28 are fed by the MFS.

If you test the back of the fuse for 26 & 28, and have power on both sides with the headlamp switch turned to the head position, time to check for power at the headlamp bulb connector.

PS : See you do not have Autolamps, do you have DRLs ?

 

I dont have power at the fusebox with the headlight switch on. MFS then ?. By the way, no autolamp for me.

 

Also switched out the relays and still no go

 

Pull the MFS and test it with the chart above, but if fuse slots #26 & #28 have no power with the main headlamp switch on, I would think MFS or the connector in the steering wheel column.

What relays did you swap, there are none without Autolamps on a 1997 ( see diagram above from the 1997 EVTM cell 85-1 headlamps, no autolamp )

 

Here is what I have so far:

Power on one side of both fuse sockets, fuses are good, no power at the light sockets. Is there a connector behind the fuse block that might have worked loose ( over a year ago I replaced the heater core, so all of the dash has been pulled out and stuck back in - in the process something might have been affected - again over a year ago).

Thanks for the help so far.

 

ok. changed the MFS and I have headlights. thanks for the help. by the way, changing out the switch was scary easy. thanks again