Hi guys. So I'm new to the forum and just purchased a cherry 1993 f350 dually supercab 7.3 turbo idi. Absolutely love this truck. I'm having a small problem I noticed tonight my cruise control doesn't work tonight and was showing a buddy of mine the truck and he noticed my brake lights weren't working. Turn signals work, hazards work but brake lights don't. I pulled the harness off the switch on the brake pedal and had power. I tried a jumper between the two pins to see if the problem was the switch but the lights didn't come on.

I did some research and am now thinking it is the multi function switch or the wiring in the steering column. I tried moving the column around to see if it would make a difference and nada.

Am I on the right track? if I fix the brake problem will it fix the cruise control. horn works so fuse is good.

Thanks in advance

 

Could also be the turn-signal switch itself. Since the brake light circuit flows through brake light switch, then the turn signal switch, then out to the lights via the same wires as both the turn signals and the 4-way hazard flashers.
It's very possible that something with the cruise control is messed up because of that same thing as well, but I'm not sure how that would all play out. Just not familiar enough with the later wiring in these trucks as I'd like to be.

You may be able to test all the wires at the base of the column for function, before trying to remove the switch, but it's a fairly convoluted process what with all those wires.
But it can be done. I'm sure others will know more.

Good luck

Paul

 

Ok. I was looking at the price of a new multifunction switch and they aren't that bad. My wipers were behaving oddly as well so I'm suspecting the switch is on its way out. I'm going to stay by opening the column and checking the wires for breaks. my only problem is I work 98 hours a week lol so it doesn't leave me much time to wrench.

 

It is just a dirty multi function switch, open it up and clean a lub the contacts.
Common problem.
I had to clean mine also on my 1993.

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Thanks a lot. That doesn't look to tough. I'll pull it tonight when i get home and make a mess on the wife's kitchen table hahaha.

Thanks again to both of you

 

It may not take care of the speed control but it should fix the brake lights.

 

Ok so I cleaned up all the contacts on that switch and voila brake lights work. Only problem is they work with a jumper wire but not the switch. so either the switch is stuck or it's not making proper contact because if I pull it towards the floor slightly it will work. I took it out and it looks good. I'm going to try cleaning it and if that doesn't work I'll pick up a new one Monday.

Thanks for the help guys. That switch was pretty oxidized. Oh and for anyone that stumbles on this post when you reassemble the switch make sure the plastic slider fits onto the handle tab for you headlight dimmer. first time I assembled it feel all the way into the slot and my high beams wouldn't turn off even with the key off.

Now onto the cruise control. I'm not sure if this solved the problem but I'll find out hopefully tomorrow night.