After inexhaustive research, (
)it appears the cruise stalks are prone to failure.
Really easy test for you:
Under the dash, find the 4 wire connector for the cruise control. I believe this connector on a stock setup SHOULD be clipped to a bracket on the underside of the column towards the base. The connector on the turn signal stalk end is a wierd single blade style connector. Anyways, find that connector, and disconnect it. On the blade connector, get a multimeter (or anything you can use to check continuity) and touch the probes to two of any of the four "tracks" (it's actually a circuit board) while simultaneously depressing the resume/accelerate and set slider/button. You should have continuity between all of them.
A related test that isn't going to completely narrow it down, is to turn the key to "run", and pull the plug from the module, which is just above the gas pedal. There should be 12V to one of the wires, regardless of the switch position. There is a brake switch between the cruise stalk power wire and the module, but that one is not that easy to get to with the dash together. That switch will cut the voltage to the module if the brake pedal is depressed. Obviously the testing gets much more in depth than this, but if you don't have 12V to the module, then you know the problem is either the power feed, the cruise stalk, the switch, or the wiring in between.
Of the two stalks I have, both appear to have failed by the above two tests. As far as I can tell, there is no way to take them apart. I have a feeling the small wires break inside the stalk. Anyways, later (about '90-91 according to my manual) GM started putting a connector right at the turn signal switch, so I'm assuming they figured out there was an issue, although it did make it easier for manufacture, as they simply added those wires to the ribbon cable that feeds the turn signals.
I repeated this test on two later cruise stalks (with the connector up top) from the wrecking yard, both of them pass the first test. Can't use them until I go back to the wrecking yard and disassemble a column far enough to separate the cruise wires from the ribbon cable. Then my column comes back apart. Fun!
All the other wiring is pretty robust in the system, the module and servo would seem to be the other two failure points, although the servo seems to be pretty stout. The manual has tests for these two components too of course, but they are more complex than the above two tests.
)it appears the cruise stalks are prone to failure. Really easy test for you:
Under the dash, find the 4 wire connector for the cruise control. I believe this connector on a stock setup SHOULD be clipped to a bracket on the underside of the column towards the base. The connector on the turn signal stalk end is a wierd single blade style connector. Anyways, find that connector, and disconnect it. On the blade connector, get a multimeter (or anything you can use to check continuity) and touch the probes to two of any of the four "tracks" (it's actually a circuit board) while simultaneously depressing the resume/accelerate and set slider/button. You should have continuity between all of them.
A related test that isn't going to completely narrow it down, is to turn the key to "run", and pull the plug from the module, which is just above the gas pedal. There should be 12V to one of the wires, regardless of the switch position. There is a brake switch between the cruise stalk power wire and the module, but that one is not that easy to get to with the dash together. That switch will cut the voltage to the module if the brake pedal is depressed. Obviously the testing gets much more in depth than this, but if you don't have 12V to the module, then you know the problem is either the power feed, the cruise stalk, the switch, or the wiring in between.
Of the two stalks I have, both appear to have failed by the above two tests. As far as I can tell, there is no way to take them apart. I have a feeling the small wires break inside the stalk. Anyways, later (about '90-91 according to my manual) GM started putting a connector right at the turn signal switch, so I'm assuming they figured out there was an issue, although it did make it easier for manufacture, as they simply added those wires to the ribbon cable that feeds the turn signals.
I repeated this test on two later cruise stalks (with the connector up top) from the wrecking yard, both of them pass the first test. Can't use them until I go back to the wrecking yard and disassemble a column far enough to separate the cruise wires from the ribbon cable. Then my column comes back apart. Fun!
All the other wiring is pretty robust in the system, the module and servo would seem to be the other two failure points, although the servo seems to be pretty stout. The manual has tests for these two components too of course, but they are more complex than the above two tests.
