cruise control measurements/info

[kastein]

Yeah, they only changed a few values internally and added the circuit fault checking resistor that's always in the circuit. They left the 15400 and 2940 values the same.

My impression is that they did this to evenly space the values in an exponential cascade so that they can be distinguished from each other more easily. Each value in 99-01 is 1.6-2.5x the previous one. That is also true of the 97-98 values but they were able to be farther apart because there are 5 sense ranges that need to be distinguished from each other rather than 6 as on 99-01.

 

[fenns7]

Alright, due to a project I am presently working on I had need of actual, 100% verified data on this. So I went and found a guy selling some and offered him less than they were worth simply to measure and inspect them. He thought that was pretty weird (I mean, I don't blame him) but was OK with the idea. So here are the measurements.

The actual resistor values inside the 99-01 56007530AD and 56007531AD cruise control panels:
20500 ohms (no buttons pressed)
15400 ohms (in series with Resume/Accelerate button)
5490 ohms (in series with Set button)
2940 ohms (in series with Coast button)
1240 ohms (in series with Cancel button)
464 ohms (in series with On/Off button)
All resistors are 1/10 or 1/8 watt, 1% tolerance.
(the above is provided solely for other nerds who are interested in the electrical internals of the switch modules. This information is of no practical use to anyone just bolting parts onto their jeep. The next list is for you.)


THE ACTUAL VALUES YOU WILL READ WITH AN OHM METER, WITH BOTH LEFT AND RIGHT BUTTON PANELS CONNECTED TO YOUR HARNESS CORRECTLY, ASSUMING YOUR SWITCHES ARE GOOD AND THE GREEN PLUG TO THE CLOCKSPRING IS UNPLUGGED TO KEEP THE ECU OUT OF YOUR MEASUREMENTS:
20500 ohms (no buttons pressed)
8794 ohms (Resume/Accelerate pressed)
4330 ohms (Set pressed)
2571 ohms (Coast pressed)
1169 ohms (Cancel pressed)
454 ohms (On/Off pressed)
Values may be off a bit depending on your meters accuracy but should be within about 1-5%. For example my meter read 20400, 8790, 2570, 4340, 453, and those values are well within range if you are sanity checking your hardware.

I'll update the first post now to avoid any confusion.

Yeah, they only changed a few values internally and added the circuit fault checking resistor that's always in the circuit. They left the 15400 and 2940 values the same.

My impression is that they did this to evenly space the values in an exponential cascade so that they can be distinguished from each other more easily. Each value in 99-01 is 1.6-2.5x the previous one. That is also true of the 97-98 values but they were able to be farther apart because there are 5 sense ranges that need to be distinguished from each other rather than 6 as on 99-01.

As always Kastein I really appreciate the research you upload to this site. Most generous.