: cruise control not working in 1991 fleetwood

08-25-10, 05:20 AM

cruise control lamp is just showing, is there any possibility to solve this issue??

08-25-10, 10:17 AM
What do you mean by lamp is just showing? If it is on, there is a little orange dot that represents that the cruise is turned on. And then when you set the speed, a little green dot will appear letting you know the cruise is active.

08-25-10, 08:29 PM
Finlay I have an excuse to bring out my GM Electronic Cruise service manual...

Does anyone know the system used on the '90's Brougham? Is it the DFI Cruise or the Custom Cruise III system? Both have some components, which look like they're apart of my car's cruise control system, and some components that don't match.

Once I get a better description of the problem, I can give you the diagnostic process for solving the issue.

08-25-10, 08:33 PM
I have the 90 and 91/92 manual. I can check if you told me what to look for.

08-25-10, 08:36 PM
Hey! I was here first! Find another sandbox...

08-25-10, 09:04 PM
Does anyone know the system used on the '90's Brougham? Is it the DFI Cruise or the Custom Cruise III system?

I was talking about to answer this question. I have no clue about cruise control systems and will be tuning in for my daily edumacation.

08-25-10, 10:39 PM
I was just kidding anyway...

The Cadillac service manual I have does not say which system is used. My cruise control manual was published in 1987, and states that Custom Cruise was applied to all GM vehicles, except Cadillac, in 1984. Cadillac stayed with the DFI system, which looks correct in the dash switch, but the servo depicted in the DFI section is completly different than the one on my car. The vacuum servo used on the Custom Cruise system looks like the right one. It really looks like Cadillac cherry picked some of the DFI electronics and vacuum controls and mixed it with the Custom Cruise system, which messes things up in that it's a mutant hybrid.

Do the '90's cars have a servo with two vacuum ports or one or three? Do the '90's cars have a vehicle speed sensor, vacuum control valve/relay, and Auto/Cruise/Off functions on the switch?