What does this connector do?

[likearaptor]

Hi,

I noticed this wire was disconnected underneath the steering column. I soldered it back to the connector but I would like to know what it does. I haven't noticed any changes.

[Vega_67C10]

Did you check for and voltage coming from that wire or from the connector that you plugged it into? Just wondering, if nothing changed then it was probably a dead circuit that wasn't in use.

Have you looked at any diagrams or schematics?

[likearaptor]

It didn't have any volts on it and I tried turn on/off many switches on the turn signal lever and other items in the steering column but I got nothing. I was hoping I could find out what is causing the cruise control to not work.

When I got the truck cruise control didn't work. I was going to try some tests on the wires in the steering column to see if I could find out where the cruise control ones were but I couldn't find it. Does anyone have suggestions to find out if it is the lever or the cruise control module?

[ChevyTech]

The connector in the photo with the broken wire is for the windshield wipers.

The wire harness for the cruise control switch is much smaller.

The brake switch is a common cruise control failure point.

Take a photo that is not so close and a little lower on the column and it may have the cruise wiring in it.

Tell us what model year your truck is. It is hard to give good advice when we don't know what you are working on.

[likearaptor]

Originally Posted by ChevyTech

The connector in the photo with the broken wire is for the windshield wipers.

The wire harness for the cruise control switch is much smaller.

The brake switch is a common cruise control failure point.

Take a photo that is not so close and a little lower on the column and it may have the cruise wiring in it.

Tell us what model year your truck is. It is hard to give good advice when we don't know what you are working on.

It is a1989 Chevy K2500, extended cab, 350 motor, with a 5 speed. I'll try to get a better picture. Doors any one know what colors of the wires are so I can find it easier?
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[ChevyTech]

Originally Posted by likearaptor

Doors any one know what colors of the wires are so I can find it easier?

The cruise wires are tiny and molded together inside a small gray/black covering/tube.

Colors:
Pink/black
Dark blue
Dark Green
Gray

[ChevyTech]

Cruise switch wires colors:
Pink wire with black stripe = power in from gage fuse
Gray wire = power out of switch to brake switch and cruise module
Dark blue wire = Set & coast
Dark green wire = Resume & accelerate

[likearaptor]

Originally Posted by ChevyTech

Cruise switch wires colors:
Pink wire with black stripe = power in from gage fuse
Gray wire = power out of switch to brake switch and cruise module
Dark blue wire = Set & coast
Dark green wire = Resume & accelerate

Thanks so much, I'll start working on troubleshooting the wires.

[ChevyTech]

You're welcome.

Here are some tests you can do under the hood:

Unplug the wire connector from the cruise module on the cruise unit under the hood.
Check for power on the Pink wire with black stripe (with the key on) – there should be power.
Check for power on the Gray wire (with the key on and cruise switch on) – there should be power.
Check for power on the Brown wire (not touching the brake pedal) – there should be NO power.
Check for power on the Brown wire (while the brake pedal is pushed) – there should be power.

[likearaptor]

Originally Posted by ChevyTech

You're welcome.

Here are some tests you can do under the hood:

Unplug the wire connector from the cruise module on the cruise unit under the hood.
Check for power on the Pink wire with black stripe (with the key on) – there should be power.

There was power

Check for power on the Gray wire (with the key on and cruise switch on) – there should be power.

There was power

Check for power on the Brown wire (not touching the brake pedal) – there should be NO power.

There was no power

Check for power on the Brown wire (while the brake pedal is pushed) – there should be power.

There was no power.

So I assume I need to get a new brake switch for the pickup. I also tested gray wire without the cruise control turned on and there was no power. So I know at least the on/off switch is working. What should I look for on the Dark Blue & Dark Green wires on the steering column for when I try to push those buttons on the cruise control switch to make sure they are working?

[ChevyTech]

You found a problem with the power through the brake switch to the cruise.

The brake switch is a common failure part.

I would not bother doing any more testing untill you get the brake switch issue fixed. There is a very chance that is the only problem.

Edit: I erased the part about changing the switch because your 1989 truck switch is not hard to change like the 1994 & newer trucks.

For C/K trucks 1988 to 1993

Brake Switch mounting – Installing:
The body of the brake switch should not move with the pedal at all. Remove the switch and install it again. When you have the switch removed look at the side of the switch that would be towards the parking brake pedal if the switch were still installed. There is a protrusion on the switch that must slide into an opening where the switch mounts. Somewhat like a big square lug into a slot.

Here is how the switch is adjusted:
On the curved side of the switch, which is pointing down and somewhat towards the front of the vehicle when installed, the end of a lever protrudes slightly out of a slot.
While holding the brake pedal down a little ways, slide the lever that protrudes from the slot toward the driver’s seat.
Let go of the lever, and then return the brake pedal to its fully released position, and the switch should self adjust.

[likearaptor]

Originally Posted by ChevyTech

You found a problem with the power through the brake switch to the cruise.

The brake switch is a common failure part. They are not easy to change.

I would not bother doing any more testing untill you get the brake switch issue fixed. There is a very chance that is the only problem.

Thanks, I'll do that first. Also on a side note, how do you remove the real wheel brake computer box? It looks like there is a plastic clip that is on the part closer to the driver that needs to be pulled as you pull it away from the driver
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[ChevyTech]

Originally Posted by likearaptor

Thanks, I'll do that first. Also on a side note, how do you remove the real wheel brake computer box? It looks like there is a plastic clip that is on the part closer to the driver that needs to be pulled as you pull it away from the driver
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I use a little screw driver to pry the tab/clip out a little to remove the RWAL module. Only pry as far as needed to remove it because the plastic gets very brittle as these trucks age, and it is very easy to break the tab/clip off.

[ChevyTech]

The brake switch I am referring to is the switch by the brake pedal and not anything under the hood.

You could try adjusting the switch as see if it takes care of the problem.

Make sure the brake lights work correctly.

This style switch can loose and the adjustment can then move when it shouldn't.

[likearaptor]

So I got the brake switch installed yesterday (your installation instructions were way better than Oreilly Auto Parts) thanks.

I did a quick test run of the cruise control last night and I didn't have any luck. I will re-test the brown wire on the cruise control module wire plug just to make sure the brake switch is working. I assume it is since I tested each of the three switches on the brake switch before installing it.

[likearaptor]

So I checked the cruise control wires and found out 2 bad things. One, now I do not get power on the gray wire when cruise control is on, and the other is the brown wire still doesn't have power when brake is applied. So I am going to troubleshoot the brown wire and see what is going on. My brake lights are working just fine and the one connector used for the cruise control on the brake was working before I installed the new brake switch. I also checked the Brake fuse and it is fine. Little by little I will get everything working like it should.

One interesting note, once I replaced the brake switch the brake light stopped appearing while driving. I thought it was the RWL ECU but maybe it was just letting me know the brake switch was bad?

[ChevyTech]

Originally Posted by likearaptor

So I checked the cruise control wires and found out 2 bad things. One, now I do not get power on the gray wire when cruise control is on, and the other is the brown wire still doesn't have power when brake is applied. So I am going to troubleshoot the brown wire and see what is going on...

The brown wire gets feed from the gray wire circuit. Fix the problem to get power on the gray wire first.

If the pink wire has power with the key on and the gray wire does not get power when you turn the cruise switch on (with the key on), then the cruise switch or the wires to it are bad.

Originally Posted by likearaptor

One interesting note, once I replaced the brake switch the brake light stopped appearing while driving. I thought it was the RWL ECU but maybe it was just letting me know the brake switch was bad?

It is very common for the brake switch to fail and cause RWAL problems.

Check out this thread where we are talking about cruise control:
http://67-72chevytrucks.com/vboard/s...=1#post5482048