Engine/Transmission (1998.5 - 2002) Anatomy of an APPS

[Gary - K7GLD]

Well guys, I just could NOT take the suspense any longer!!!!! NO solid state electronics. Oo. Oo. Oo. Oo. I don't have time right now to explain anything but I'll be back, I'm already late for another project!!

HMMmmm - looks as tho' the pin connectors solder direct to the circuit board, and the IVS function is accomplished using a slider/carbon track type switch - pretty neat!



That's so simple, makes you wonder why the one DC uses is so dern complex and gimicky!

 

[timbo]

HMMmmm - looks as tho' the pin connectors solder direct to the circuit board, and the IVS function is accomplished using a slider/carbon track type switch - pretty neat!



That's so simple, makes you wonder why the one DC uses is so dern complex and gimicky!

That's exactly what I'm seeing Gary. Also if you look closely at the carbon tracks to the top of the sensor which is the poteniometer,the slider fingers do NOT go off the track. When it's NOT mounted to the bracket, the fingers of the slider sit on a none conductive green material, and then carbon track continues a couple degrees clockwise on the board. Looks to be designed and functions EXACTLY LIKE THE SCHEMATIC DIAGRAM that cummins supplied to DC, previously posted in this thread. It stated " OEM Responsibility". Why couldn't they just keep it simple like the schematic shows.

 

[timbo]

That's the way I see it as well...



Do you on any of your Williams setups, see the resistance reading go to open-circuit at either or both ends of travel? I see that on the one I have, but figure once it's installed on it's bracket, the idle and WOT stop screws will keep in within the tracks...



I think I'll drag mine out, and check it again, with a different meter...

I just edited my last post gary. Check it out.

 

[Gary - K7GLD]

Also if you look closely at the carbon tracks to the left of the sensor which is the poteniometer, slider doesn't go off the track.

(we were correcting posts at the same time... )



That's the way I see it as well...



Do you on any of your Williams setups, see the resistance reading go to open-circuit at either or both ends of travel? I see that on the one I have, but figure once it's installed on it's bracket, the idle and WOT stop screws will keep in within the tracks, ot at least that portion of the tracks that seems functional...



I think I'll drag mine out, and check it again, with a different meter, sometimes digital meters act flaky...

 

[timbo]

When it's NOT mounted to the bracket, the fingers of the slider sit on a none conductive green material, and then carbon track continues a couple degrees clockwise on the board.



Looks to be designed that way.

 

[Gary - K7GLD]

WELL, just verified it with a good quality analog meter, my Williams potentiometer section definitely shows open circuit to the wiper at each end of rotation...

 

[Gary - K7GLD]

When it's NOT mounted to the bracket, the fingers of the slider sit on a none conductive green material, and then carbon track continues a couple degrees clockwise on the board.



Looks to be designed that way.

Not really a problem, and not likely to display the same effect once mounted and calibrated to it's mounting bracket - but it IS something to be aware of, and check during setup...

 

[mhenon]

. . Do you on any of your Williams setups, see the resistance reading go to open-circuit at either or both ends of travel?...

That's what I read on the two I checked. The reading would go right off the scale if you checked the APPS while not installed in the bellcrank. Once it was fixed in either the Dodge bellcrank or Williams pedal assembly it stayed on the resisitance tracks and gave the expected readings. I believe this happened on either end of travel. . but it's been a while since I looked at it.

Mike

 

[Gary - K7GLD]

I've sent the following PM to Timbo - but figure he rates a PUBLIC bouquet! :-laf

Tim, I want to thank you again for the pins you sent - finished up my own adapter cable for the Williams-to- DC hookup, and will keep it for my own spare - but this note is ESPECIALLY to thank you for taking the time, and going to the expense of opening up a Williams APPS to reveal internal circuitry!



As far as I am concerned, the design of the Williams APPS, combined with your adapter harness, makes your setup by far the best choice in a low-buck replacement! GREAT WORK!



Regards



Gary

 

[PRout]

Just popping my head in here quickly and updating status on the K7GLD Revived Apps. . It's still purrrfect! Gotta love it.

I forgot to mention I have a P. S. High Idler added inline with the APPS harness as well. No compatibility problems at all. In fact, I got an extra 150 rpms out of it, now can adjust high idle up to 1500, was about 1350 max before. Quick guess is the combined "R" of the circuit is probably slightly different from one apps to another. Ok, back to focusing on the Williams unit. .

 

[rweis]

I have had a couple of guys (2 so far) from "Diesel Truck Resource" email me about failing APPS. I tell them to go to this thread and get Timbo's number to order the APPS and plug adapter package. I think this could become a fairly wide spread thing, but only a few at a time as APPS fail would be my guess.



Can a "guest" to TDR read these threads?



Bob Weis

 

[timbo]

Thanks Gary for the PM, and Bob thanks for directing guys my way. It's a good feeling to help out others with affordable APPS sensors, and just these trucks in general. Bob, guests can only read threads 5 days back, I think.

 

[muchsnow]

APPS Replacement

Looks good guys !!! Here is my finished product also. Just plug it in.

Finally installed this, already a noticable difference between this and the six month old DC replacement that was already failing.

I'll get another one for the glovebox, which should ensure that the current installed never goes bad huh?... ... .

Thanks alot folks,

L. J. M.

 

[PRout]

Good for you guys. . FYI, I just returned from an 1100 mile trip still using Gary's modded apps. It has been flawless (knock on wood).

 

[mhenon]

Good to hear everyones running down the road with no problems.



I just had a leaky AC line replaced by a local repair shop. They told me the whole crew was bent over the engine bay looking for the APPS until it was spotted on the pedal assembly. Then they went looking for the fuel filters, LP and batteries. Kinda funny!

Mike

 

[blacksheepdiesel]

Sorry to rain on your parade Mike, BUT...

My "Gary-fied" APPS with MS worked flawlessly for about 8k and then last week I started getting 0222 codes. Checked that MS and found it needed some "precision" alignment which I did. Couple days later, same code, same adjustment. Couple more days same code. Finally discovered that the two small nuts/bolts that hold the MS to the bracket had loosened and would not hold proper position. Tightened and now no more codes. My guess is vibration so anyone with a MS may want to consider threadlock or perhaps starwashers.

Godspeed,
Trent

 

[Gary - K7GLD]

Sorry to rain on your parade Mike, BUT...



My "Gary-fied" APPS with MS worked flawlessly for about 8k and then last week I started getting 0222 codes. Checked that MS and found it needed some "precision" alignment which I did. Couple days later, same code, same adjustment. Couple more days same code. Finally discovered that the two small nuts/bolts that hold the MS to the bracket had loosened and would not hold proper position. Tightened and now no more codes. My guess is vibration so anyone with a MS may want to consider threadlock or perhaps starwashers.



Godspeed,

Trent

YUP - good idea to keep an eye on the MS fasteners, and if needed, apply Locktite or some similar retaining method. Mine is fine after several thousand miles, but will watch it. Actually, since this MS method is pretty insensitive to precise adjustment in relation to the APPS resistance section, and that adjustment can easily be made with the idle side OEM adjuster on the stop post, once the MS is close to proper position, you could easily permanently fix it in position, and then just use that other adjustment for fine tuning...

 

[PRout]

discovered that the two small nuts/bolts that hold the MS to the bracket had loosened and would not hold proper position. Tightened and now no more codes. My guess is vibration so anyone with a MS may want to consider threadlock or perhaps starwashers.

Godspeed,
Trent

Good point! Think I'll bond those fasteners in place with some epoxy.

(We're always improving here on the TDR)

 

[Gary - K7GLD]

Good point! Think I'll bond those fasteners in place with some epoxy.



(We're always improving here on the TDR)

I really don't expect them to move much ordinarily, and since the actual adjustment is pretty non-critical, just that the MS contacs reliably open/close just off resting idle at the bellcrank, I may simply apply a little crazy glue to mine...

 

[rweis]

I mounted mine with nyloc nuts. Not likely to vibrate out of position. I have had no problems, but driving the truck much less now.



Actually I hardly ever use regular nuts and lock washers on anything anymore for the same reason.



Bob Weis