SkipBurney
Full Access Member
The cruise control on my 89 F 250 dosent work at all Does anyone have any suggestions as to where I should start to look
Cruise control dosent work
- Thread starter SkipBurney
- Start date
gandalf
Senior Member
I had the same problem, long ago, with my '86. As I recall the horn and the cruise control share a relay which, on the '86, is located under the dash, about mid-way across. How much that may have changed by 1989 I can't guess, but it's worth a thought. If it was the same, test the horn.
Also, I have 2 diagnostics I'd be happy to send you. They're apparently too large to post here. If you'd like them send me an email address by PM here on the site.
Also, I have 2 diagnostics I'd be happy to send you. They're apparently too large to post here. If you'd like them send me an email address by PM here on the site.
79jasper
Chickenhawk
Several common areas: cruise control cutout switch on the brake master, the buttons on the wheel, and iirc a bulb out can possibly cause it.
Sent from my SM-N960U using Tapatalk
Sent from my SM-N960U using Tapatalk
79jasper
Chickenhawk
SkipBurney
Full Access Member
My vacuum reservoir on one of mine looked good, but the coffee can was literally in two pieces at the bottom so anytime I'd try and use cruise I'd just dump all my vacuum. One way to test that is have someone hold their hand over the defrost vent for you while flying down a straightaway with the ac on high. If it puffs out from the defrost when you try and turn the cruise on your dumping vacuum somewhere and the hvac defaults to defrost.. just remember your brakes are vacuum too and take a couple seconds to build vacuum assist back up.
SkipBurney
Full Access Member
Just checked and my horn works
Noiseydiesel
Full Access Member
My fix was too easy. I went through and started looking at voltages. Then I removed and cleaned/greased all grounds. behind kick panels and under hood front and rear as well as the end of the bed. Errant voltages went away and cruise came back to working.
ComatoseLlama
Full Access Member
Adding ~6ga ground wires from battery, to back of alternator, to block, to frame has solved a lot of issues on a lot of cars for me
Mine wasn't working properly at one point and needed the dump valve under the dash adjusted. Worth a look at least. It wasn't closing when the brake pedal was all the way up. Slid it down so it closed properly and whamo cruise!
motorhed
Registered User
Mine was a unplugged harness above and near the fuel pedal.Discovered my clutch switch was bad after re-connecting it.Did a dirty clutch switch bypass someone on this site posted and it is working again.Downside,it doesn't kick off the cruise when I downshift on the manual.I learned real quick to hit the off button.
IDIBRONCO
IDIBRONCO
I know that they're "supposed" to, but I had a brand new 1995 ****** with a 5 speed that did the same thing.
This is '85 but should be about the same: http://www.thedieselfiles.com/Ford/1985/Speed Control Cruise.pdf
