87cutlasssupreme

newbie here. my question is my 87 cutlass supreme's cruise worked great untill the 307 dropped a valve and munched the motor. so installed a 350 from a 77 cutlass. i used the 77 distributer and set aside the computer componets. now i've lost my cruise control. none of my local mechanics can tell me why. they say the computer doesn't control the cruise. any ideas? thanks in advance for any help.

Yellowstatue

The computer doesn't control the cruise, did you check to see if you have engine vacuum to the servo?? and the throttle linkage?? and if the front of the sevo has an electric plug on it it could be that it went to lunch without you!!

Bluevista

I'm not familiar with those but I looked at Auto Zone and it has a cruise control module/amplifier, cruise switch, fuse, stoplight switch and a vacuum reservoir available, somewhere to start. What YS said otherwise, went to lunch?
Is your cruise running? better go catch it before it gets away.

Lady72nRob71

I am assuming it worked well soon before the engine swap...

I cannot remember if the cruise uses a separate speed sensor or the one the computer uses. I will try to remember to look in my chassis manual when I get home. I am thinking they are independent.
Is the cruise module under the dash still there? (The one that the turn signal mounted switches plug into?)
Check the things already mentioned like vac lines and brake release vac switch and I will get back with ya later...

The good thing is that the 350 was a very good replacement for that 307 - it needed to happen anyway...

kartmaster

For 84 and up you'll need to make sure you still have the servo, vacuum reservoir, cruise computer module, vehicle speed sensor, and of course the switches on the stalk.

The cruise system can function perfectly without the ECM, but if you remove the ECM wiring, you also remove the ground for the VSS. Simply ground the black/white stripe wire running from the VSS and if the rest of the system is intact, your cruise control should function normally.

Good luck!

Lady72nRob71

Just looked at the manual... Kartmaster is correct.
Here are some more details...
The speed sensor in the speedo provides for ECM and cruise.
There will be 3 wires coming from it to a small buffer (amplifier) unit mounted below the cluster to the right of the column.
Aside 3 wires going in from the speedo, there are 4 more wires going to and from it.... All are needed for you except the brown one (it feeds the ECM).
The pink is the buffer power feed, taken from the 10A ECM / DEC fuse. Perhaps you yanked that fuse?
Black is ground and the red goes to the cruise module.
Hope this helps...

87cutlasssupreme

I want to thank all whom replied about my cruise. After pulling my head out and re-reading wiring diagram it made sence that it wasn't grounded. Now it works perfectly! taps up, taps down, and resumes. Bad thing is, I am certified undercar technician. But never been good at wiring. Thanks again.

citcapp

Another reason why Classic Oldsmobile is a great site another problem solved by active members good job