brake lights turn signals

[nepatternmaker]

My 97 F350 PSD CC recently lost both turn signals and brakes lights. I have power to the t/s flasher, the fuses are all good and the bulbs are good. Any relays hidden somewhere that would be related? Most of what I'm finding by searching is the multifunction switch, but that's a lot of work and expense, I want to make sure that's the problem before I tear into it. Any multifunction switch troubleshooting guides on here?

thanks
dave

[pipelayerjdh]

You are probably on the right track with mf switch. There isn't anything else in the equation on the obs trucks. If the brake light switch and headlight switch are ok, then the mf switch is most likely the problem. When i had a problem with mine i just swiped on from another truck. A superduty mf switch will work too if you have a buddy that will let you test it out.

[nepatternmaker]

how do I know the headlight switch and brake light switch are ok? headlights work, is that enough? Is the brake light switch as simple to test as it ought to be, or have they made it complicated? Also I pulled the hazard and t/s flashers, I have no continuity thru the t/s flasher and 50 ohms resistance thru the hazard flasher. 50 seems like a lot. The haz flasher is an old style short metal can w/ 2 contacts, the t/s flasher is a semi-transparent deal with a visable coil , contacts and circuit board.

Thanks for you help. i do mechanical, but I'm colorblind and have never understood things electrical.

dave

[pipelayerjdh]

i understand. The brake light switch is simple, open/close. the headlight switch is good if the headlights and running lights work. so, im pretty sure you have a mf switch problem. at least thats where i would start.

[95dieselsmoke]

Hi pipelayer, I am having the exact same problem. Could you tell me where the mf switch is? It is driving me crazy trying to figure out my problem. Thanks in advance.

[pipelayerjdh]

Its the conglomeration of a turn signal switch on the column. Too bad they couldn't leave it like they were in the pre-'92 models with a dimmer on the floor.

[95dieselsmoke]

Ok Derrick, can you tell me if that switch goin bad would cause the cruise control to stop working? Again, thanks.

[supreme oppressor]

Do you have reverse & tail lights? if not, look for a bad ground in the harness near the back, including the pins in connectors.

[95dieselsmoke]

Originally Posted by supreme oppressor

Do you have reverse & tail lights? if not, look for a bad ground in the harness near the back, including the pins in connectors.

I do have running lights, but no reverse or brake lights. Where are these pins in connectors that you speak of?

[nepatternmaker]

I do have running lights, haven't checked back ups, I'll do that when I get home tonight.

dave