1990 Cruise Control won't maintain speed
Melting Slicks
Joined: Sep 2008
Posts: 2,376
Likes: 111
From: Cherokee National Forest TN
Insure the vacuum source is good & adjust the cable to eliminate as much free play as possible. There are 5 or 6 holes in the servo bracket for cable adjustment.
Check the switches on the brake pedal & if 6sp the clutch pedal to insure they are not engaged when the pedal is not depressed.
There is a check out procedure in the FSM. After testing the servo ohms do not follow the FSM for the next step to test the cruise module as it is a real PITA to access, instead move to the thin wires from the multi function lever to test for power to the multi function lever from the module @ the wire connector. Mine was zip tied to the column. Next check the functions of the cruise switch with an ohm meter @ the wire connector. If you do not obtain an ohm reading from the various lever functions the lever will need to be replaced.
If the servo ohms out ok & you have 12v at the wire connector with key on, brake & clutch switches are ok & the multi function lever ohms out ok, you will probably need to replace the cruise module. It lives on top of the Bose radio tuner right side of dash behind the fuse box.
Luck.
Check the switches on the brake pedal & if 6sp the clutch pedal to insure they are not engaged when the pedal is not depressed.
There is a check out procedure in the FSM. After testing the servo ohms do not follow the FSM for the next step to test the cruise module as it is a real PITA to access, instead move to the thin wires from the multi function lever to test for power to the multi function lever from the module @ the wire connector. Mine was zip tied to the column. Next check the functions of the cruise switch with an ohm meter @ the wire connector. If you do not obtain an ohm reading from the various lever functions the lever will need to be replaced.
If the servo ohms out ok & you have 12v at the wire connector with key on, brake & clutch switches are ok & the multi function lever ohms out ok, you will probably need to replace the cruise module. It lives on top of the Bose radio tuner right side of dash behind the fuse box.
Luck.
Last edited by Churchkey; Jun 24, 2011 at 02:42 AM.
