1991 Mustang GT cruise control not working

Cobrajet67 · 05-26-2008

My 1991 GT's cruise doesn't work and the fuses are good. Does anyone out there know what common problems would be for this? I assume the speed sensor would be the likely culprit but I'm not sure, wouldn't that affect the speedo or computer somehow? I am having low idle problems.

Kyle F · 05-26-2008

Sounds like a vacuum line issue to me. I would do a Quick one over of all your vacuume lines.

**EagleAutosports** · 05-26-2008

Power for the cruise control comes in through the DRL/Fog/Horn fuse in the engine compartment fuse box. It then goes through the horn relay (don't ask me why) , through the clockspring in the steering wheel and then to the cruise control switch.
So, if the cruise control and the horn doesn't work, it is likely the horn relay or the clockspring assembly is bad. If the horn does work, then the clockspring assembly or the cruise control switch is bad.

Cobrajet67 · 05-27-2008

Yeah, my horn does work. Where is the clockspring-in the cruise transducer itself? It could be a vacuum leak but I went thru it and saw no lines disconnected. There was one that was when I bought the car it went to the smog pump check valve or something connected to that system but I have since repaired that. Thanks guys I'll look into all those. And wow! EagleAutosports-you really know the cruise system in and out!!!

swreadspb@yahoo · 05-27-2008

The cruise stopped working on my '91 LX after a "pop" sound that seemed to come from the steering wheel direction. The Ford dealer wouldn't even attempt to repair it since the age of the vehicle put it out of his familiarity. The corner garage offered to "start changing parts until it starts working" but I declined that offer thinking they might choose to start with the rear bumper and work forward.
I'll print out the diagnostic tree you were kind enough to share and give it a go. Thanks Eagle.

RCRacer94gt · 05-27-2008

I have no clue what the problem is. but My brother had tranny work done to his car and after that the cruise worked when it didnt before.

Cobrajet67 · 05-28-2008

that sounds like the speed sensor since it's located on the trans. I had my AOD trans shipped to TCI over the winter to have it built to Streetfighter status so maybe my speed sensor isn't in all the way or something.

ZD302GT · 10-09-2009

my cruise stopped working and all the fuses are still good. the horn still works too. I hope its not the clock spring. where is the "control Module" for cruise? what else can i check? i already checked the vacuum lines too. thanks

ColaScStang · 10-09-2009

I know this is an old thread but I'd like to know too. I think the last owner may have ripped all or part of teh cruise out as teh cruise cable is MIA and I don't know what else to check or where.

ZD302GT · 10-13-2009

common people, Anyone?