Cruise control inoperable on 91 OCC

I bought a 91 occ about a year ago. Cruise didn't work when I purchased the wagon. Noticed to cable from the cruise control module was broken and rigged to the throttle body. Changed out module with one from my 93 Caprice Sudan. Still didn't work. Ended up changing module, the multifunction stock, vss module under the dash, tcc switch and brake switch from working Caprice to wagon. Still no cruise control. Followed every step from the fsm and everything checks good. Have 5 volts at the vss module. I'm lost, does anyone have any ideas. And today my odometer and trip stopped working. Speedometer and tac still work fine. Is there something in the cluster maybe that's not letting these all work properly

The same signal is used for the speedo, odo, trip odo, and the cruise control. There is a module under the dash that is a signal modifier. It puts out 4K pulses per mile to the above, and 2K pulses per mile to the computer. It is also rumored, and some have validated that the CC does not work unless the bulbs in the CHSL are good.

Check your grounds at the bottom of the A pillar on the driver's side. Your connector for the VSS may have come off. I would check it.

Are the gears the same for the VSS from the Caprice? There are 2 types of VSSs. One for 40+ tooth gears, and one for 39- tooth gears. The 40+ came on the 3.23 gear cars, and the 39- came on the 2.73 cars.

3rd brake light works. I changed the vss module under the dash. Never changed the vss on the transmission. I'll check my grounds tomorrow. So is the module under the dash the same vss module that you're talking about

I mentioned both the one under the dash, and the one on the trans. If you did not mess with the one on the trans, it should be OK.

I would check grounds, and the connector to the VSS module under the dash.

I'll look at it tomorrow. So the vss module runs the speedo, odometer, trip, and cruise control?? By the way. The complete rear end had been swapped out with a 9c1 rear. There shouldn't be anything there that deals with the cruise control, right??

Nothing in there deals with the CC, but the gear ratio may make your readings inaccurate. I do not know what your original ratio is, but if it is substantially different, your pulse per mine from the VSS will be off.

The 9c1 rear has 3:08 factory had 3:23. Speedometer is correct.

The speedo should be different. The original VSS gears usually make the speedo fast. That may actually be the correct driven gear for that rear. Other than that, it should not affect the speedo, etc.

Same car, same problem. Changed all the same parts and still not working. I also made a by-pass connector from the multi-function switch to the harness, hoping that the thin gauge wires in the steering column might be the issue. No luck.

The connections at the module have letter designations and this is where the circuits are tested. I don't have a signal from the multi-function switch.

I was thinking mine was a broken wire in the column. I'll have to figure this out today.

I checked my vss module connections and I have 5 volts at terminal D on connection c1.

Follow the trouble shooting tree in the FSM. It will tell you exactly where the problem is. I cut into a 12v source on one of my cars in order to fix it.

And, third brake light function is not tied to cruise on wagons. Just sedans. To help future trouble shooters.

I followed the fsm steps and everything checks good by those steps

Changed out my vss module now my odometer and trip are working still no cruise control

Swap out the cruise/turn signal stalk. Takes about two minutes.

I've changed it 4 times

So my odometer and trip stopped working again. Swapped out vss module with another that works and still odometer doesn't work. Put the old vss module in my Caprice and everything works in the Caprice. Idk what to do anymore. Jayoldschool what 12 volt source did u cut into to make yours work. Can you explain that to me

I followed the FSM yes/no page. When I found one wire that was supposed to be hot, it wasn't. So I connected that to another one that was hot. Lost the RESUME feature, but cruise worked.

I'll go back through that list from the fsm again

Finally got the crusise control working on my 91 OCC. It was a loose pin connector to the module under the dash.

Send me a PM and I will send you the FSM trouble shooting flow chart and the wiring diagram. I also have a spare controller that mounts to the inner fender, part #25075216 B