What relay is missing? Is it the CC disable relay?

[bleizit]

I'm having difficulty getting my cruise control to work and have read numerous threads on several forums. I've confirmed the steering wheel, dash and brake switches are good. The pump is operational. Actuator is good. Hoses and T have been replaced. The neutral lockout relay has not been tested, but the switch is operational in it's default setting. I cannot locate the CC diable relay anywhere in my truck. The manual I have shows it in a vehicle with steering on the right. In that case it's located on the drivers kick panel. I assume mine would be also; however, I have an open slot where I believe it should be. There are two blue and a black wire going to the white base. Check out the picture if you know these D1's and tell me what you think. Would a YWB10032 relay go there? How does the disable relay work? Can you bypass it to test the ECU? The photo is from behind the LH footwell panel.

 

[joey]

Ok, does the light on the dash come on when you turn on the cruise?

Have you checked the diaphragm that the cruise uses to pull back the throttle.

Mine had holes it in (cracks) I used some adhesive silicone on mine and it would like a champ...

 

[Maddie]

Don't know if it is anything like a 95 I don't think so but.... You should have test that will test the pump and the diaphram. Ie: in a 95 undo ecu . Looking at the harness short pins 1 and ten with a fusible link and then tie pin 6 to ground with a fusible link and pin 7 to ground with fusible link of the harness. Cruise on, ignition in position two and actuator should retract. I've done all test to my 95 and it's the ecu. Placed a used one in. It lasted for about a month retested bad ecu....... Notorious in 95's. I think the tests in this site has all the same test proceedures that I have in my electronic manual.

 

[bleizit]

Joey - Dash light comes on. The actuator bellows depress very slowly, thus indicating a good diaphragm. Correct? I've never heard of this diagnostic; however, I took off the vacuum hose at actuator and used a vacuum pump to apply a steady bit of pressure and system hold fine. Depressed brake pedal and pressure immediately drops. I'm so tempted to throw a YWB10032 relay in the open socket and see what happens. I know better... but there was that 6-pack plus incident in 93...

 

[Maddie]

If the bellows are slow seems to me it indicate a leak or bad pump suction as mine is very quick and pulls all the way back in say about 5 seconds or less. How are you testing this are you just putting voltage on the pump? And don't forget about the speed sensor. In my vehicle you have to lift the rear driver side wheel and spin it whilst testing a pin on the harness for a square wave otherwise off and on voltage with a vom or scope. I'm not computer savy enough to tell you where to look for the total test proceedure but I would think it's in this sight. This is a great site. Very good people and info..

 

[bleizit]

There is a bit of difference in the CC system between the 95 and the '99D1SD. When the actuator is manually compressed it takes several seconds, which I called slow. It releases, like yours, in about 4-5 seconds. When the bellows break, they typically release immediately. I believe the problem is electronic and it may be ECU. I'm not one of those that just starts buying replacement parts and throw them at her, so I'd love some info on testing the ecu. I follow several forums and am amazed that no one seems to know much about the disable relay. I'm betting the open socket is the CC disable relay. The speed sensor was replaced 3-4 years ago. I have no other symptoms of it failing. I removed the pump, applied 9V current and it pumps like a demon. The switches have all been tested when removed from the vehicle. I replaced the brake switch because one of the clips was broken and it wasn't secure enough in the housing. I'd appreciate any help. Especially for those of you that have a 99D1SD... please look behind your drivers side kick panel and tell me what relay (if any) is there.

 

[bleizit]

Bump... Any ideas???

 

[joey]

Ok, this is what I want you do try. Remove the vacuum line from the back of the throttle pulling unit (cannot remember it's name) push the unit in, place finger over the vacuum hole. Let go of the end you pushed in. If it stays this piece is good, if it releases within 5 seconds you need to either replace or fix this part.

Next have you tried using a vacuum tester to ensure all the hoses are good, from the pump to the brake peddle and the 'T' and to the intake?

Lets rule out other issues before we start on electrical.

 

[bleizit]

The actuator holds solid as a rock until I take my the vacuum hose is opened. I used a vacuum pump and held pressure from actuator to brake switch. Depressed brake pedal and pressure is immediately released. Vacuum pressure to pump holds tight as well. I've removed pump and applied 9v to the unit and it pumps away. Cruise dash switch comes on, but no CC. I have a new YWB10032L relay and was going to swap it for the lockout relay and try that. Any ideas?

 

[joey]

At the point with all the trouble shooting you have done, it sounds more like the cruise ECU. But a relay could be the issue. Swap the relay and see.

I am not one to throw parts at anything, so I would pull the Cruise ECU tear it apart and look for bad solder joints.