Big Blue's Transformation

[Gary Lewis]

Thanks for the details, Bill. Looks like I'll need to find another connector for the few high-current circuits. The fog lights, backup lights, and trailer lights would be some of those. Hmmm, I'd better check the fuel pressure relay to see what circuit # it is and what pins it used.....

Jim - Thanks. Yes, Silver Lining is the powder I'm using on a lot of things, inc the valve covers, intake plenums, dipstick stay, coil mount, and the alternator & power steering/AC compressor brackets. And the stash of aluminum channel has come in so very handy, with parts being made for the dipstick stay, coil mount, battery hold downs, and now the fog light bracket.

As I've told Janey any number of times, I really enjoy working in my shop. Being able to make things that are needed, like for the truck, is so rewarding. And figuring out how to use the tools is a big part of that. Yesterday I was wondering how I was going to make the indention in the bracket, but then I remembered that I could angle the mill vise, so I measured the angle, set the vise, and milled the angles. Then I set the vise back to 0 and milled the straight part to connect the angles. And the part fell out.

Guess what came in today! I know what I'm going to do tomorrow.

As for what I did today, I got the fog lights mounted and the wiring done save for up to a non-existent relay. Here's the front view:

And here's the side view:

[grumpin]

Guess what came in today! I know what I'm going to do tomorrow.

As for what I did today, I got the fog lights mounted and the wiring done save for up to a non-existent relay. Here's the front view:

And here's the side view:

Looks really good! And a new toy, I mean tool!

[Gary Lewis]

Looks really good! And a new toy, I mean tool!

Thanks, Dane! Yes, a new toyol.

[ArdWrknTrk]

Thanks, Dane! Yes, a new toyol.

The lights do look good.

And hopefully you can troubleshoot your glitchy speed control.

Progress is GOOD!

[Gary Lewis]

The lights do look good.

And hopefully you can troubleshoot your glitchy speed control.

Progress is GOOD!

Thanks, Jim.

Reading the instructions on the tester it looks to me like the problem is likely to be in the potentiometer circuits that feed the servo's position back to the electronic module. Basically that's the only thing that's not been checked from what they say to test.

So, I'll start with the "servo test", which does test those circuits. Then, if that doesn't find something, I'll go back to the automatic test, which checks everything.

[ArdWrknTrk]

Thanks, Jim.

Reading the instructions on the tester it looks to me like the problem is likely to be in the potentiometer circuits that feed the servo's position back to the electronic module. Basically that's the only thing that's not been checked from what they say to test.

So, I'll start with the "servo test", which does test those circuits. Then, if that doesn't find something, I'll go back to the automatic test, which checks everything.

A pesky Pot could well be your problem.

At least it could be replaced on that board if some de-oxit doesn't bring it back.

I cut my teeth on circuitry like that, and feel you're able to effect repair.

Newer boards with densely packed SMD's are challenging for my shakey hands and eyesight (even with an optivisor)

[Gary Lewis]

A pesky Pot could well be your problem.

At least it could be replaced on that board if some de-oxit doesn't bring it back.

I cut my teeth on circuitry like that, and feel you're able to effect repair.

Newer boards with densely packed SMD's are challenging for my shakey hands and eyesight (even with an optivisor)

The "pot" in question is the one on the servo, not the one on the board. All three legs of the servo's pot feed back to the board and the instructions suggest that if any one of those doesn't come through you'll have surging.

As I think about it, I don't know if the pot on the servo that's on there is any good. I did change the servo out but that servo's Vacuum valve didn't work so the speed control didn't function at all. And when I put the original servo back on I didn't test its pot.

Reading the test procedure in the section of the FSM we have on the Speed Control page I did discover that the pot is said to be necessary to prevent surging. So I could have pulled that servo and tested its pot. And I could have used my DVM to test the three circuits back to the module. But by the time I realized that Scott already had the tester on its way to me so I moved on to the fog light bracket.

The test procedure tells me to:

• Place the tester in Harness Testing mode

• Plug the tester's cable into the two connectors that go to the module

• Turn the key to Run

• Remove the connector from the servo

• Touch the probe attached to the tester to each of the six terminals in the connector for two seconds, at which point there is to be a readout showing that terminal is connected to the harness correctly

I don't know if the connector really has to be connected to the servo when the tester "wakes up", but that's the order the instructions give, so that's the order I'll use.

Hmmm, I need to copy some of this discussion over to the other thread.

[Gary Lewis]

The "pot" in question is the one on the servo, not the one on the board. All three legs of the servo's pot feed back to the board and the instructions suggest that if any one of those doesn't come through you'll have surging.

As I think about it, I don't know if the pot on the servo that's on there is any good. I did change the servo out but that servo's Vacuum valve didn't work so the speed control didn't function at all. And when I put the original servo back on I didn't test its pot.

Reading the test procedure in the section of the FSM we have on the Speed Control page I did discover that the pot is said to be necessary to prevent surging. So I could have pulled that servo and tested its pot. And I could have used my DVM to test the three circuits back to the module. But by the time I realized that Scott already had the tester on its way to me so I moved on to the fog light bracket.

The test procedure tells me to:

• Place the tester in Harness Testing mode

• Plug the tester's cable into the two connectors that go to the module

• Turn the key to Run

• Remove the connector from the servo

• Touch the probe attached to the tester to each of the six terminals in the connector for two seconds, at which point there is to be a readout showing that terminal is connected to the harness correctly

I don't know if the connector really has to be connected to the servo when the tester "wakes up", but that's the order the instructions give, so that's the order I'll use.

Hmmm, I need to copy some of this discussion over to the other thread.

Speaking of copying things to the other thread, I'm copying these things from the other thread...

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.

[ArdWrknTrk]

Speaking of copying things to the other thread, I'm copying these things from the other thread...

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.

If this is a vacuum system perhaps a reservoir with one of those vacuum restrictions would buffer how abruptly the speed control engages?

[Gary Lewis]

If this is a vacuum system perhaps a reservoir with one of those vacuum restrictions would buffer how abruptly the speed control engages?

Hmmm, maybe!

It would be easy to put a restriction in the vacuum supply by making a fitting that accepts a carb jet and has hose barbs on either end. But not so easy in the vent as I think it is just a hole in the housing. But, maybe I can drill and tap it to take a little hose barb, and then play with carb jets on it as well.

I'll look tomorrow, but that may be a much better way of smoothing things than doing it electrically. http://www.garysgaragemahal.com/uploads/6/5/8/7/65879365/thinking-26_orig.jpg