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

[rweis]

Rather than find the non IVS Williams APPS ($$$. $$) (which only the micro switch IVS crowd could use anyway) I think I am going to adapt Gary's $2 slider to a $10 industrial potentiometer (volume control) to carry as an APPS backup (which only the micro switch IVS crowd could use anyway). This would put the APPS replacement at $18 ($8 micro switch, $10 potentiometer + 1 bracket for the potentiometer + 1 bracket for the micro switch) and make it truly a "spare parts" box item.



The potentiometer because the auto transmission and speed control guys need the potentiometer to be in the APPS pocket, and I already bought 2 high quality potentiometers to experiment with during the project if we did not find something like the Williams Controls APPS.



The "all in one" APPS (APPS & IVS) would stay with the Williams Control 131973 and the wire adapters already discussed.



Bob Weis

 

[Gary - K7GLD]

Rather than find the non IVS Williams APPS ($$$. $$) (which only the micro switch IVS crowd could use anyway) I think I am going to adapt Gary's $2 slider to a $10 industrial potentiometer (volume control) to carry as an APPS backup (which only the micro switch IVS crowd could use anyway). This would put the APPS replacement at $18 ($8 micro switch, $10 potentiometer + 1 bracket for the potentiometer + 1 bracket for the micro switch) and make it truly a "spare parts" box item.



The potentiometer because the auto transmission and speed control guys need the potentiometer to be in the APPS pocket, and I already bought 2 high quality potentiometers to experiment with during the project if we did not find something like the Williams Controls APPS.



The "all in one" APPS (APPS & IVS) would stay with the Williams Control 131973 and the wire adapters already discussed.



Bob Weis

Well, I plan to drive this setup until it drops, to test the long range durability and reliability of the cheapie pot I used. The bracketry can be changed to gain more room, and the noise/spike filter and the pot resistance padder assembly can easily be reduced in size and located away from where I located them on my setup, to make room for the added linkage as used by automatic transmission setups.



The greatest weakness I can see in the pot I used, is that the inner slider and resistance strips are relatively exposed, and vulnerable to stray garbage getting inside, although that area seems to stay pretty clean in normal operation...

 

[rweis]

I'm going to play with the extra APPS bracket you sent me.



I think I can duplicate the Williams APPS potentiometer only for $10, with a 10,000 ohm heavy duty 10,000,000 rotation life cycle potentiometer with 320* of rotation.



What I am going to do to fool the ECM is to put 2470 ohms of resistance from the zero end of the potentiometer to the ECM (ie NOT go through the pot).



Then set the pot so it starts at about 400 ohms of resistance with the wiper track so the ECM thinks it is 400 ohms up on the track when the bell crank is at idle.



The bell crank rotation to the potentiometer rotation is 17. 5% (54* of bell crank compared to the 320* of real potentiometer capability) or 1750 ohms. Plus the start of 400 ohms the ECM should think it goes from 400 ohms to 2150 with a 2470 total range.



To mount it just cut the slot for the blade of the bell crank into the potentiometer shaft and put it into a flat piece of stock that spans between the APPS mounting holes. Use the same WeatherHead connectors for the potentiometer. Plug 'er in.



That and the micro switch brings the APPS cost to $18 or less than going to McDonalds with the grandkids which seems to cost at least $20 plus.



Anyway, should be fun playing with it. Then the question is what the heck do we do with all these failed DC APPS ?



Anyway, I'll mess around with it some.



Bob Weis

 

[mhenon]

... Then the question is what the heck do we do with all these failed DC APPS ?. .

There's actually a process where they can be ground up and turned into diesel fuel. Given the rate they fail compared to crude at over $100. 00 a barrel... . should be a toss up!!!

Mike

 

[rweis]

FYI



The APPS screws are 5mm x . 8 pitch x 1 3/4" long.



With the extra bell cranks and APPS floating around I needed the screws and had to measure old ones to see what fit. THis will save you the trouble doing the same thing.



Bob Weis

 

[FLynes]

Bob,



Once you have a final working model, can you post a list of everything that we, the non-engineers, need, along with instructions on putting this bad boy together?



Thanks a million for the work you guys have done on this.

 

[rweis]

Sure,



It is going to be a little while getting around to this since we know the Williams APPS works and works well for the general user.



However, since we now know that the APPS is nothing more than a potentiometer and a micro switch, and a couple of us are running the micro switch to validate that, it only stands to reason that we can go forward and literally substitute a potentiometer (very very high quality volume control) in place of the Williams APPS --A S S U M E S--you have already done the micro switch to take care of that IVS (idle validation) function.



You still have to have:



1. an idle validation method (micro switch)

AND

2. a variable voltage method (potentiometer)



Which is what the Williams Control does both functions.



Parts:



1. The micro switch has to have a bracket to sit on (several brackets in this thread or be creative and come up with something else you like better)

2. The potentiometer will have to have a bracket to hold it over where the traditional APPS is

3. The micro switch it self (Mouser Electronics)

4. The potentiometer which is what I will try to figure out in the comming weeks (Mouser Electronics)

5. The wiring to get the signals into the DC wire harness (Work it so it all fits into the pigtails that have been made up)



I just have to figure which "volume control" would be the best for the range we need (size, range, temperature characteristics), how to mount it, how to wire it in. It may not even be possible, who knows.



If it is though, then the micro switch and potentiometer being common electronic components cuts the cost pretty drastically. However, then it has to be tested for longivity and failure proofing. Just because there is another way does not mean it is better than where we already have been.



Who knows?



Several have the Williams Controller and therefore are testing that.



I have the APPS & micro switch (we could use more guys testing that approach).



Gary has the linear potentiometer & micro switch (we could use more guys testing that approach)



Maybe we will have the potentiometer and micro switch as well.



Maybe 4 choices when there once was only DC.



But it all takes time to see how it goes.



Bob Weis

 

[Allnew2Me]

Great thread and lots of really good info. Thanks to all for the groundwork.

I had a question that is related to this process that maybe someone can answer.

Seeing as how the APPS is just a variable resistor, would it be possible to add a switch with a resistor of a given value that would allow a fast idle? I would shy away from a pot inside only because there would be too much risk of turning it up too high. If the proper resistance could be found for say, 1000 or 1200 RPM that would be a cheap and effective way to get a fast idle.

 

[timbo]

Great thread and lots of really good info. Thanks to all for the groundwork.

I had a question that is related to this process that maybe someone can answer.

Seeing as how the APPS is just a variable resistor, would it be possible to add a switch with a resistor of a given value that would allow a fast idle? I would shy away from a pot inside only because there would be too much risk of turning it up too high. If the proper resistance could be found for say, 1000 or 1200 RPM that would be a cheap and effective way to get a fast idle.

This would be correct. You would install it in the ground wire. I'm just getting ready to add this as an option to my williams set-up, but I didn't quite get the time yet. I varified it does work with a potentiometer I just can't decide if I want to make an adjustable high idle or just a fixed 1100-1200 rpm.

 

[KarlC]

This would be correct. You would install it in the ground wire. I'm just getting ready to add this as an option to my williams set-up, but I didn't quite get the time yet. I varified it does work with a potentiometer I just can't decide if I want to make an adjustable high idle or just a fixed 1100-1200 rpm.

I've thought about this too, and am also planning on building something when I get the time. :-laf

Consider that if the voltage from the APPS pot gets too high without switching the IVS it could set codes and drop back to idle.

 

[Gary - K7GLD]

Several have the Williams Controller and therefore are testing that.



I have the APPS & micro switch (we could use more guys testing that approach).



Gary has the linear potentiometer & micro switch (we could use more guys testing that approach)



Maybe we will have the potentiometer and micro switch as well.



Maybe 4 choices when there once was only DC.



But it all takes time to see how it goes.



Bob Weis

The GOOD news here, is that virtually EVERY substitute setup tried so far, is working EXCELLENTLY!



ALSO, I'll soon have a pair of units going out with the MS for the IVS, and salvaged OEM APPS modules that check good in the potentiometer section - will be interesting to see how they perform and last when installed and operated for a while...

 

[timbo]

I've thought about this too, and am also planning on building something when I get the time. :-laf

Consider that if the voltage from the APPS pot gets too high without switching the IVS it could set codes and drop back to idle.

I've bench tested it and found that adding resistence to the ground wire raises output voltage, it also RAISES the point IVS switches so I don't think were going to have a problem with it, but I've only tried it in a quick experiment on the truck. I'm getting around to it though so we'll see.

 

[FLynes]

Hey, if it'll help the cause, I'll volunteer my truck for testing purposes. I'm all about getting DC and their high price rip-offs out of the picture.

 

[rweis]

Well, if you were in Florida I would take you up on that.



Any trucks in Florida having APPS problems and want to try different solutions? I would like to be able to be there as we make the modifications, but I guess it is not absolutely mandatory.



Probably could do the micro switch IVS which might solve most of the potential APPS problems.



What do you think? I have not done one by "remote" yet. Should be a good test.



Bracket for the micro switch

Plugs to mate it to the DC harness

Install instructions



What year truck? Auto transmission?, Manual transmission?, Cruise Control? I do not think that the APPS bracket changes from year to year.



Bob Weis

 

[FLynes]

Well, if you were in Florida I would take you up on that.



Any trucks in Florida having APPS problems and want to try different solutions? I would like to be able to be there as we make the modifications, but I guess it is not absolutely mandatory.



Probably could do the micro switch IVS which might solve most of the potential APPS problems.



What do you think? I have not done one by "remote" yet. Should be a good test.



Bracket for the micro switch

Plugs to mate it to the DC harness

Install instructions



What year truck? Auto transmission?, Manual transmission?, Cruise Control? I do not think that the APPS bracket changes from year to year.



Bob Weis

Well, Bob, you walk me through it and I have no problem turning the wrenches... I used to be an helicopter mech, so I know my way around the toolbox



2001 HO

Manual 6-speed

Cruise Control

 

[Allnew2Me]

It sounds like this could be a very easy addition, adding a high idle switch. My APPS is fine now but I am going to get one of these Williams units as a backup. Thanks again to all the ones doing the real work.

 

[rweis]

OK,



Let's do this right here in the forum so others can see what is needed to be done.



1. I will get a bracket made up and mail it to you. Email me your address so I can send it next week.

2. YOU order the micro switch Mouser on line catalog:

Mouser part # is #653-D2VW-5L2A-1MS just type that in the search box at the top of the Mouser on line catalog page. I checked the $ and today it was $8. 33.

3. Wiring: Are you going to use the DC APPS potentiometer? Probably easiest, least expensive and should work just fine, we will add the micro switch for IVS.



IF you use the DC APPS potentiometer:



We are going to need to splice the micro switch wiring into the DC harness neatly. So how about ordering a male and female M=DT04-6P Assy, F=DT06-6S Assy. I would get the gold pins (adds $7 / $8 to the cost of the connector) wire size 16-18 AWG because the APPS voltges are so small and small differences seem to make a big difference.



http://www.deutschconnector.com/cgi-bin/store/agora. cgi?cart_id=289777. 6852*_Z7-N2&xm=on&product=DT_6-Contact|DT_Sealing_Plug|Mounting_Accessories



The concept is we are going to wire DC harness pins 3,4,5 (the apps potentiometer pins) straight through, and 1,2,6 are for the micro switch. When we get done the DC APPS will have a plug with only 3 wires comming out of it (the potentiometer wires). The DC wire harness plug will have all 6 wires (the potentiometer wires plus the micro switch (IVS) wires.



You get the micro switch and the male and female Deutsch connectors, I will make up the bracket and send it and then we should be all set up put it all together.



If you want to do the bracket like Gary has shown also let me know, but I think I need to make up some brackets anyway.



IF something does not make sense please tell me. Please keep track of the cost so we know what the "IVS conversion" really cost (I see $34. 84 plus shipping)



Bob Weis

 

[JLandry]

I now have about 2000 miles on my Williams APPS and wanted to post a quick update on how my Williams APPS has been performing...



I'm currently 8 days and about 1600 miles into 9 day trip pulling a 25 foot travel trailer from the Seattle area to Death Valley, CA and back... up and down countless steep mountain passes.



The Williams APPS (part number 131856 from kit number 131973) has worked flawlessly the entire trip. It's indistinguishable from the original it replaced.



Best regards,



John L.

 

[Gary - K7GLD]

As I had mentioned earlier concerning my own setup using the MS for the IVS function, combined with a cheap in-line potentiometer, I had never paid any attention to actual voltages, and instead merely duplicated the resistances of the OEM APPS at idle and full pot resistance.



I received a PM from a member over on the Cummins Forum, who was duplicating my setup, but was having problems because his idle voltage at the pot was slightly above . 8 volts. Obviously, too high, and I advised him to reduce the voltage somewhere well below . 7, and best at about . 5.



Just for kicks, since I was under the hood of my truck doing other maintenance, I decided to actually measure my own idle voltage, for the first time. It was (gasp!) flickering between . 5 and . 51 volts - EXACTLY what the OEM APPS was marked as being. I guess relying on matching resistance of the OEM setup DOES work... :-laf:-laf:-laf

 

[FLynes]

OK,



Let's do this right here in the forum so others can see what is needed to be done.



1. I will get a bracket made up and mail it to you. Email me your address so I can send it next week.

2. YOU order the micro switch Mouser on line catalog:

Mouser part # is #653-D2VW-5L2A-1MS just type that in the search box at the top of the Mouser on line catalog page. I checked the $ and today it was $8. 33.

3. Wiring: Are you going to use the DC APPS potentiometer? Probably easiest, least expensive and should work just fine, we will add the micro switch for IVS.



IF you use the DC APPS potentiometer:



We are going to need to splice the micro switch wiring into the DC harness neatly. So how about ordering a male and female M=DT04-6P Assy,

F=DT06-6S Assy. I would get the gold pins (adds $7 / $8 to the cost of the connector) wire size 16-18 AWG because the APPS voltges are so small and small differences seem to make a big difference.

http://www.deutschconnector.com/cgi-bin/store/agora. cgi?cart_id=289777. 6852*_Z7-N2&xm=on&product=DT_6-Contact|DT_Sealing_Plug|Mounting_Accessories



The concept is we are going to wire DC harness pins 3,4,5 (the apps potentiometer pins) straight through, and 1,2,6 are for the micro switch. When we get done the DC APPS will have a plug with only 3 wires comming out of it (the potentiometer wires). The DC wire harness plug will have all 6 wires (the potentiometer wires plus the micro switch (IVS) wires.



You get the micro switch and the male and female Deutsch connectors, I will make up the bracket and send it and then we should be all set up put it all together.



If you want to do the bracket like Gary has shown also let me know, but I think I need to make up some brackets anyway.



IF something does not make sense please tell me. Please keep track of the cost so we know what the "IVS conversion" really cost (I see $34. 84 plus shipping)



Bob Weis

Okay, Bob, sounds like a plan to me. I'll get online tonight and get everything I need. I think that the DC APPS is the best route, money-wise, and it will give us a good baseline to measure reliability and longevity.



Here's my address:



Frederic Lynes

6969 Harriett Rd.

San Angelo, TX. 76905



I'm getting excited about this!