Speed Control Testing

[Gary Lewis]

Yes, looks like the same one. The molded plastic hinges on the case broke when Matt was using it on his 1986 F150. I haven't seen a tester for the electronic speed controls.

Then I'm interested.

But it might be a reason to stay with the vacuum system if that tester doesn't work with the new electronic ones. Plus, I might figure out how to make the vacuum systems do what I want easier than doing the same with the electronic one since I have access to the signals between the servo and the brains on the vacuum system. And, there's that tantalizing potentiometer that may take the sensitivity out.

 

[Gary Lewis]

Then I'm interested.

But it might be a reason to stay with the vacuum system if that tester doesn't work with the new electronic ones. Plus, I might figure out how to make the vacuum systems do what I want easier than doing the same with the electronic one since I have access to the signals between the servo and the brains on the vacuum system. And, there's that tantalizing potentiometer that may take the sensitivity out.

Bill - It looks like there is an ID # on this speed control board: E3AF-14A608-DA.

[Gary Lewis]

Bill - It looks like there is an ID # on this speed control board: E3AF-14A608-DA.

Bill - Looks like I'd like that tester sooner rather than later. See below.

Scott - As said in the text, I can't get your tester to work properly. According to the instructions, which I've now put on this page (Documentation/Electrical/Speed Tester) the display should come on when you fire it up. But the display doesn't come on at all.

Having said that, it sorta works. I can put it in the "harness test" mode and when I test the circuits going to the servo I hear a beep on each one. But I think that just tells me that the tester "saw" that I'd made a connection and then the display is supposed to say if it is correct or not.

So I turned to the DVM and tested the servo, which passed. Then I tested the harness and on the first pass I found that the two outside legs of the potentiometer, meaning the P/LB and B/LG wires, connected to an O/LG wire in the Pin 7 position, which is supposed to be Servo Signal ( + ), which is either the P/LB wire or the B/LG wire.

But, after testing everything else, which tested correctly, I went back to those two and couldn't repeat what I'd found. IOW, they tested perfectly. And I pulled, twisted, etc all of the wires.

So I'm at a loss. I'm stuck.

Any suggestions?

[kramttocs]

Bill - Looks like I'd like that tester sooner rather than later. See below.

Scott - As said in the text, I can't get your tester to work properly. According to the instructions, which I've now put on this page (Documentation/Electrical/Speed Tester) the display should come on when you fire it up. But the display doesn't come on at all.

Having said that, it sorta works. I can put it in the "harness test" mode and when I test the circuits going to the servo I hear a beep on each one. But I think that just tells me that the tester "saw" that I'd made a connection and then the display is supposed to say if it is correct or not.

So I turned to the DVM and tested the servo, which passed. Then I tested the harness and on the first pass I found that the two outside legs of the potentiometer, meaning the P/LB and B/LG wires, connected to an O/LG wire in the Pin 7 position, which is supposed to be Servo Signal ( + ), which is either the P/LB wire or the B/LG wire.

But, after testing everything else, which tested correctly, I went back to those two and couldn't repeat what I'd found. IOW, they tested perfectly. And I pulled, twisted, etc all of the wires.

So I'm at a loss. I'm stuck.

Any suggestions?

Sorry Gary - bad deal on that tester

Good thing Bill has a known working one.

Thanks for adding the doc though!

 

[85lebaront2]

Bill - Looks like I'd like that tester sooner rather than later. See below.

Scott - As said in the text, I can't get your tester to work properly. According to the instructions, which I've now put on this page (Documentation/Electrical/Speed Tester) the display should come on when you fire it up. But the display doesn't come on at all.

Having said that, it sorta works. I can put it in the "harness test" mode and when I test the circuits going to the servo I hear a beep on each one. But I think that just tells me that the tester "saw" that I'd made a connection and then the display is supposed to say if it is correct or not.

So I turned to the DVM and tested the servo, which passed. Then I tested the harness and on the first pass I found that the two outside legs of the potentiometer, meaning the P/LB and B/LG wires, connected to an O/LG wire in the Pin 7 position, which is supposed to be Servo Signal ( + ), which is either the P/LB wire or the B/LG wire.

But, after testing everything else, which tested correctly, I went back to those two and couldn't repeat what I'd found. IOW, they tested perfectly. And I pulled, twisted, etc all of the wires.

So I'm at a loss. I'm stuck.

Any suggestions?

Now I have to find it, I probably put it up on my "storage floor" over the office, bathroom and wood shop. Once I track it down I will pack it and the spare modules and send it West.

[Gary Lewis]

Now I have to find it, I probably put it up on my "storage floor" over the office, bathroom and wood shop. Once I track it down I will pack it and the spare modules and send it West.

Thanks, Bill! In the interim I'll re-test the pot's wiring, and if I don't find a problem I'm going to start positioning the air cleaner and PDB. Then when I get your tester I'll compare to Scott's and see if I can figure out what is going on with it.

[Gsmblue]

Thanks, Bill! In the interim I'll re-test the pot's wiring, and if I don't find a problem I'm going to start positioning the air cleaner and PDB. Then when I get your tester I'll compare to Scott's and see if I can figure out what is going on with it.

Gary, Keep in mind I have a tester arriving around 1/2 that I would be happy to send on for you to borrow too.

Once it arrives with me I will let you know how it goes. I am sure I will have questions about it anyhow.

[Gary Lewis]

Gary, Keep in mind I have a tester arriving around 1/2 that I would be happy to send on for you to borrow too.

Once it arrives with me I will let you know how it goes. I am sure I will have questions about it anyhow.

Thanks! It isn't urgent as I have plenty to do on other things, so let's see how this plays out.

[Gary Lewis]

Thanks! It isn't urgent as I have plenty to do on other things, so let's see how this plays out.

Well, the FSM section on Speed control says "Speed control system tests should be performed using the Rotunda Tester Model 007-00013 or equivalent. If the Model 007-00013 Tester is not available, use the Following procedures." And then it has you testing for voltage here, resistance there, ect.

So, I tested components as best I could and assembled a system out of the best of the pieces. And then I followed the instructions for testing, and found nothing. NADA. Everything checked out.

But, knowing that there's a potentiometer buried in the electronic "amplifier" I drilled a hole in the housing to allow access, as you can see in the pic. And, I marked the case where the current setting is. But when it came time to "install" the amplifier I realized that the access to the hole wouldn't be easy, so I held it in place w/a zip tie in a position where I could tweak it when stopped.

Then we took the truck for a drive. You'll remember that the last time I had it out there were two problems - a 6 MPH surge when you hit Set, and an aggressiveness to holding the speed that caused it to overcompensate on throttle settings.

Well, when I hit Set the set point was spot-on with the speed we were going. Yippee! But, it was still too aggressive. So I pulled over and turned the pot counterclockwise a bit. And after that set point was a little lower. Then I turned it clockwise quite a bit and when you hit Set the speed jumped 3 MPH up. Last, I turned it all the way counterclockwise and the set point was 3 MPH low.

But, there didn't seem to be any change in how aggressive the speed control is. So apparently that pot only controls where the set point is and not the sensitivity.

I'll put it back to the marks and expect the set point to be just right. However, I'm not happy with how aggressive it is and will be thinking about how to change that to smooth things out.

[85lebaront2]

Well, the FSM section on Speed control says "Speed control system tests should be performed using the Rotunda Tester Model 007-00013 or equivalent. If the Model 007-00013 Tester is not available, use the Following procedures." And then it has you testing for voltage here, resistance there, ect.

So, I tested components as best I could and assembled a system out of the best of the pieces. And then I followed the instructions for testing, and found nothing. NADA. Everything checked out.

But, knowing that there's a potentiometer buried in the electronic "amplifier" I drilled a hole in the housing to allow access, as you can see in the pic. And, I marked the case where the current setting is. But when it came time to "install" the amplifier I realized that the access to the hole wouldn't be easy, so I held it in place w/a zip tie in a position where I could tweak it when stopped.

Then we took the truck for a drive. You'll remember that the last time I had it out there were two problems - a 6 MPH surge when you hit Set, and an aggressiveness to holding the speed that caused it to overcompensate on throttle settings.

Well, when I hit Set the set point was spot-on with the speed we were going. Yippee! But, it was still too aggressive. So I pulled over and turned the pot counterclockwise a bit. And after that set point was a little lower. Then I turned it clockwise quite a bit and when you hit Set the speed jumped 3 MPH up. Last, I turned it all the way counterclockwise and the set point was 3 MPH low.

But, there didn't seem to be any change in how aggressive the speed control is. So apparently that pot only controls where the set point is and not the sensitivity.

I'll put it back to the marks and expect the set point to be just right. However, I'm not happy with how aggressive it is and will be thinking about how to change that to smooth things out.

Gary, will this help you? Also I will throw the control modules in.