Super Cool and CHEAP TPS fix! Dial-in your OD shift point!
01-30-2006, 12:36 AM
#31
Registered User
I also have a manual swt for engaging my OD. Its a floor mounted dimmer swt that I just tap when I am ready for OD. I also have a light on the dash that comes on when the truck is in OD so I remember to turn it off when I stop.
Only problem is that without a working TPS my cruise control does not work.
For those that went the 5kpot route does your cruise control work.
Only problem is that without a working TPS my cruise control does not work.
For those that went the 5kpot route does your cruise control work.
01-30-2006, 03:45 AM
#32
Administrator
Potentiometer
BTW
Just to confuse the electronically challenged a bit more, you would want to get yourself a LINEAR TAPER potentiometer and NOT a AUDIO TAPER potentiometer for your conversion.
Linear taper = The resistance increases proportionally as you rotate the shaft.
Audio Taper = The resistance tapers up about 10% slowly till about 1/2 turn then it would increase logarithmically the remaining 90%.
If you were to get the Audio Taper you would have very little control for the first half turn, then control would come quicker and quicker as you got to the end of the rotation.
They are made for audio control because,
The human ear does not respond linearly to loudness. It responds to the logarithm of loudness. That means that for a sound to seem twice as loud, it has to be almost ten times the actual change in air pressure.
Trust me… Just ask for a linear taper.
http://www.radioshack.com/product/in...entPage=family
5K Ohm Linear Taper Potentiometer # Catalog #: 271-1714
5K Ohm Audio-Taper Potentiometer # Catalog #: 271-1720
Now I have you are all confused.
Jim
Just to confuse the electronically challenged a bit more, you would want to get yourself a LINEAR TAPER potentiometer and NOT a AUDIO TAPER potentiometer for your conversion.
Linear taper = The resistance increases proportionally as you rotate the shaft.
Audio Taper = The resistance tapers up about 10% slowly till about 1/2 turn then it would increase logarithmically the remaining 90%.
If you were to get the Audio Taper you would have very little control for the first half turn, then control would come quicker and quicker as you got to the end of the rotation.
They are made for audio control because,
The human ear does not respond linearly to loudness. It responds to the logarithm of loudness. That means that for a sound to seem twice as loud, it has to be almost ten times the actual change in air pressure.
Trust me… Just ask for a linear taper.
http://www.radioshack.com/product/in...entPage=family
5K Ohm Linear Taper Potentiometer # Catalog #: 271-1714
5K Ohm Audio-Taper Potentiometer # Catalog #: 271-1720
Now I have you are all confused.
Jim
01-30-2006, 03:51 AM
#33
Administrator
Originally Posted by DocCJV8
OK OK I give on the Bush comment.
Ok Big Problem tried this TPS fix and it did not work TPS starts out at .5 volts at idle then Drops off to .25 at wot. I did the 5k potentiometer (Radio Shack had them in stock), speedo is working so im thinking that the speedo sensor is not the problem. I am not realy clear on the wires but do understand that the middle wire goes to the middle of the potentiometer. Does any one know the right way to wire this up??? Checks all the wires and plugs they are clean inside and tight. Any Body got any ideas before I spend the $286 for this part and does any one know were to get it cheaper????? Think about adding a switch to tell the OD when to turn on. Read about this in a different DTR Forum.
If any one has any ideas pm me or reply here
Ok Big Problem tried this TPS fix and it did not work TPS starts out at .5 volts at idle then Drops off to .25 at wot. I did the 5k potentiometer (Radio Shack had them in stock), speedo is working so im thinking that the speedo sensor is not the problem. I am not realy clear on the wires but do understand that the middle wire goes to the middle of the potentiometer. Does any one know the right way to wire this up??? Checks all the wires and plugs they are clean inside and tight. Any Body got any ideas before I spend the $286 for this part and does any one know were to get it cheaper????? Think about adding a switch to tell the OD when to turn on. Read about this in a different DTR Forum.
If any one has any ideas pm me or reply here
Check my last post..
Might be your problem.
Jim
as I was 
05-22-2006, 11:27 PM
#36
Registered User
Originally Posted by McNasty
I think I wanna know where you got the potentiometer.
Call me a dumbass, cause I don't know where to even begin looking.
Thanks.
Call me a dumbass, cause I don't know where to even begin looking.
Thanks.
08-18-2006, 12:02 PM
#37
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Ok, My TPS was acting up when the truck got warm under the hood. I was testing it sitting in the garage and it appears to work fine but after driving for 15 minutes or more it would erraticly shift in and out of OD between 45 and 65 MPH. It gets really annoying quick!
A friend gave me the one out of his truck because he had done the NV4500 swap and didn't need it anymore. Unfortunately his didn't work at all!
I bought a 5k linear POTS at Radio Shack and a **** to put on its end. Last night I installed the POTS in place of the TPS. I just flipped over the POTS and held it up next to the TPS. The TPS actually has a shape on its cover that looks kind of like the shape of the POTS with its 3 connectors. Anyway I wired it just like that. I turned on the key and tested the voltage. It worked just like it should. I mounted it in my dash and away I went for testing.
I set it at at about 1/3 turn to start with. It works great! Under normal throttle, the truck shifted into OD at about 45. I found that if I turned it all the way up or all the way down it wouldn't stay in OD at all. That confused me . . .
Anyway, I can set the shift point pretty low so that I'm in OD at about 35 with normal throttle. What I was surprised to find is that that even set with a low MPH shift point like 35 or 40 I could start off with the truck FLOORED and it still didn't shift into OD till 55 or 60. I thought it would shift no matter what but it didn't. The truck consistantly shifts at a higher MPH if you are are full or almost full throttle regardless of where the POTS is set. To me, this seems good but I don't understand why this happens. Can someone enlighten me on this?
End result: I'm very happy with the modification. It saved me a bunch of money and the truck drive just like I would expect it too. Since throttle (or horspower going into the tranny) still seems to control the shift point to some extent, I think it works better than it did with the TPS when it did work correctly.
I can take pics if anyone wants them.
Chass
ct
A friend gave me the one out of his truck because he had done the NV4500 swap and didn't need it anymore. Unfortunately his didn't work at all!
I bought a 5k linear POTS at Radio Shack and a **** to put on its end. Last night I installed the POTS in place of the TPS. I just flipped over the POTS and held it up next to the TPS. The TPS actually has a shape on its cover that looks kind of like the shape of the POTS with its 3 connectors. Anyway I wired it just like that. I turned on the key and tested the voltage. It worked just like it should. I mounted it in my dash and away I went for testing.
I set it at at about 1/3 turn to start with. It works great! Under normal throttle, the truck shifted into OD at about 45. I found that if I turned it all the way up or all the way down it wouldn't stay in OD at all. That confused me . . .
Anyway, I can set the shift point pretty low so that I'm in OD at about 35 with normal throttle. What I was surprised to find is that that even set with a low MPH shift point like 35 or 40 I could start off with the truck FLOORED and it still didn't shift into OD till 55 or 60. I thought it would shift no matter what but it didn't. The truck consistantly shifts at a higher MPH if you are are full or almost full throttle regardless of where the POTS is set. To me, this seems good but I don't understand why this happens. Can someone enlighten me on this?
End result: I'm very happy with the modification. It saved me a bunch of money and the truck drive just like I would expect it too. Since throttle (or horspower going into the tranny) still seems to control the shift point to some extent, I think it works better than it did with the TPS when it did work correctly.
I can take pics if anyone wants them.
Chass
ct
08-18-2006, 04:40 PM
#38
Registered User
Originally Posted by Chass
Anyway, I can set the shift point pretty low so that I'm in OD at about 35 with normal throttle. What I was surprised to find is that that even set with a low MPH shift point like 35 or 40 I could start off with the truck FLOORED and it still didn't shift into OD till 55 or 60. I thought it would shift no matter what but it didn't. The truck consistantly shifts at a higher MPH if you are are full or almost full throttle regardless of where the POTS is set. To me, this seems good but I don't understand why this happens. Can someone enlighten me on this?
ct
ct
As you increase throttle, shift points are moved later and pressures in the tranny go up. You'd have to ask an auto tranny expert to know exactly how it works; I don't have much experience.
08-18-2006, 08:14 PM
#40
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I just installed the pot & love it - at least until I can find a functioning TPS for $25.
I made a plug for the three-lead cable that plugs into the cable where the TPS plugs in. That way, I can immediately go back to TPS if I want.
I used small picture-hanging nails driven thru a small piece of stock and soldered the cable's leads to the nails. I plugged it in where the TPS is connected, then wrapped the whole connector with electrical tape. The potentiometer is in the ash tray till I figure out where I want it set and where to mount it. So far, 1.00vdc causes OD shifts at 38-55mph.
Works just fine. Have to cut out OD manually if I get down around 40 and think I'm going to take off again, but I can handle that.
Good mod.
DBF
I made a plug for the three-lead cable that plugs into the cable where the TPS plugs in. That way, I can immediately go back to TPS if I want.
I used small picture-hanging nails driven thru a small piece of stock and soldered the cable's leads to the nails. I plugged it in where the TPS is connected, then wrapped the whole connector with electrical tape. The potentiometer is in the ash tray till I figure out where I want it set and where to mount it. So far, 1.00vdc causes OD shifts at 38-55mph.
Works just fine. Have to cut out OD manually if I get down around 40 and think I'm going to take off again, but I can handle that.
Good mod.
DBF
08-19-2006, 11:54 AM
#41
Registered User
Originally Posted by Chass
Anyway, I can set the shift point pretty low so that I'm in OD at about 35 with normal throttle. What I was surprised to find is that that even set with a low MPH shift point like 35 or 40 I could start off with the truck FLOORED and it still didn't shift into OD till 55 or 60. I thought it would shift no matter what but it didn't. The truck consistantly shifts at a higher MPH if you are are full or almost full throttle regardless of where the POTS is set. To me, this seems good but I don't understand why this happens. Can someone enlighten me on this?
Chass
ct
Chass
ct
The OD only works after the tranny hits third gear, when in OD you are actually in 3rd and the OD cames from a unit bolted onto the back of the tranny. So when taking off with OD engaged you still go thru first and second gear like normal, then when you hit third you'll actually go straight to OD. It has nothing to do with the TV other than because you have it floored the shift to 3rd is dealyed so much that when it goes to OD you don't realize it skipped third. The TV only affects shifts 1-3. The up/downshift to OD is controlled by the the TPS. Thats why with the POT mod you won't get a downshift when you floor it. The OD doesn't realize its floored as the TPS still sends a constant signal. You won't get a downshift unless you are going slow enough to activate a downshift to 2nd. This is the one draw back to the POT mod.
08-19-2006, 12:15 PM
#42
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Originally Posted by cLAYH
So when taking off with OD engaged you still go thru first and second gear like normal, then when you hit third you'll actually go straight to OD. It has nothing to do with the TV other than because you have it floored the shift to 3rd is dealyed so much that when it goes to OD you don't realize it skipped third.
EDIT: Oh, do you mean it works like this only after doing the POTS mod?
08-20-2006, 11:29 AM
#43
Registered User
Sorry I should have clarified.
On my truck I have a floor mounted dimmer switch that contols the OD circuit. When I want OD I tap the floor swt and the tranny goes into OD reagrdless of speed, throttle positon or RPM, provided that the tranny is in third gear. If I forget to press the swtich when slowing down to drop out of OD and come to a stop, when I roll off the light I will get 1st and 2nd gear but because I forgot to drop out the OD it will skip 3rd and goto OD.
Now if you have the POT mod and turn it down so low that you are shifting into od at a really low speed, a speed lower than what it would shift into normally for third gear it would go straight to OD.
For example lets say you had it set low for regular cruising, say 40MPH, everything is working great untill you decide to try racing that Ford Powersmoke off the line. Now you have the pedal floored and 1,2 and shift are delayed. By the time your tranny shifts up out of 2nd gear you are exceeding 40MPH and the computer is recieving a low input signal from the TPS(cause you have a POT wired in that is set for a low signal). So the computer signals for OD. Now when the tranny hits third gear, the OD circuit is already engaged so you go straight to OD, truck falls on its face and the PS goes flying by.
Simple fix is to remember to adjust the POT for a higher setting, say 60MPH, when playing around. Theoretically you could adjust the POT so low that you would never see 3rd gear even in regular driving and I think thats what Chass was doing:
"Anyway, I can set the shift point pretty low so that I'm in OD at about 35 with normal throttle. What I was surprised to find is that that even set with a low MPH shift point like 35 or 40 I could start off with the truck FLOORED and it still didn't shift into OD till 55 or 60. I thought it would shift no matter what but it didn't. The truck consistantly shifts at a higher MPH if you are are full or almost full throttle regardless of where the POTS is set. To me, this seems good but I don't understand why this happens. Can someone enlighten me on this?"
I think that with the truck floored he had a delayed shift out of second and at 50MPH with the POT set low at 35MPH it was going straight to OD. Had the POT been set higher he would have gone to 3rd at 50MPH and then OD at 60-65MPH.
On my truck I have a floor mounted dimmer switch that contols the OD circuit. When I want OD I tap the floor swt and the tranny goes into OD reagrdless of speed, throttle positon or RPM, provided that the tranny is in third gear. If I forget to press the swtich when slowing down to drop out of OD and come to a stop, when I roll off the light I will get 1st and 2nd gear but because I forgot to drop out the OD it will skip 3rd and goto OD.
Now if you have the POT mod and turn it down so low that you are shifting into od at a really low speed, a speed lower than what it would shift into normally for third gear it would go straight to OD.
For example lets say you had it set low for regular cruising, say 40MPH, everything is working great untill you decide to try racing that Ford Powersmoke off the line. Now you have the pedal floored and 1,2 and shift are delayed. By the time your tranny shifts up out of 2nd gear you are exceeding 40MPH and the computer is recieving a low input signal from the TPS(cause you have a POT wired in that is set for a low signal). So the computer signals for OD. Now when the tranny hits third gear, the OD circuit is already engaged so you go straight to OD, truck falls on its face and the PS goes flying by.
Simple fix is to remember to adjust the POT for a higher setting, say 60MPH, when playing around. Theoretically you could adjust the POT so low that you would never see 3rd gear even in regular driving and I think thats what Chass was doing:
"Anyway, I can set the shift point pretty low so that I'm in OD at about 35 with normal throttle. What I was surprised to find is that that even set with a low MPH shift point like 35 or 40 I could start off with the truck FLOORED and it still didn't shift into OD till 55 or 60. I thought it would shift no matter what but it didn't. The truck consistantly shifts at a higher MPH if you are are full or almost full throttle regardless of where the POTS is set. To me, this seems good but I don't understand why this happens. Can someone enlighten me on this?"
I think that with the truck floored he had a delayed shift out of second and at 50MPH with the POT set low at 35MPH it was going straight to OD. Had the POT been set higher he would have gone to 3rd at 50MPH and then OD at 60-65MPH.
08-21-2006, 12:12 AM
#44
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I tried bypassing my dead TPS with a POT, I can’t get it to work. I’ve read this thread numerous times to see if I missed anything.
I have the correct POT.
I’m using 18 gauge wire.
The red wire is in the center, I’ve tried switching sides on the 2 outside wires.
The truck is not charging the battery; the speedo stays at zero and the OD button light remains off. The truck died on me when I was driving it last week. After going back the next day to pick it up, I installed a fully charged battery, it fired up and everything worked fine, I had OD, the battery was being charged, the speedo was working and the OD button light was on. Then after 5 minutes of driving I lost OD again, the speedo went flat, etc. etc.
I unscrewed the speedo cable at the tailshaft and taped the rounded off shaft and slid it back in, went for a test drive…no improvement.
I put the TPS back on…no improvement.
I stared into the engine bay for 15 minutes and whispered sweet nothings ...no improvement.
Next steps, remove the taped speedo sensor and replace with a new one. Check the voltage with the bad TPS on (will this really matter?).
Any recommendations?
I have the correct POT.
I’m using 18 gauge wire.
The red wire is in the center, I’ve tried switching sides on the 2 outside wires.
The truck is not charging the battery; the speedo stays at zero and the OD button light remains off. The truck died on me when I was driving it last week. After going back the next day to pick it up, I installed a fully charged battery, it fired up and everything worked fine, I had OD, the battery was being charged, the speedo was working and the OD button light was on. Then after 5 minutes of driving I lost OD again, the speedo went flat, etc. etc.
I unscrewed the speedo cable at the tailshaft and taped the rounded off shaft and slid it back in, went for a test drive…no improvement.
I put the TPS back on…no improvement.
I stared into the engine bay for 15 minutes and whispered sweet nothings ...no improvement.
Next steps, remove the taped speedo sensor and replace with a new one. Check the voltage with the bad TPS on (will this really matter?).
Any recommendations?
08-21-2006, 12:15 AM
#45
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Originally Posted by Joe V
I tried bypassing my dead TPS with a POT, I can’t get it to work. I’ve read this thread numerous times to see if I missed anything.
I have the correct POT.
I’m using 18 gauge wire.
The red wire is in the center, I’ve tried switching sides on the 2 outside wires.
The truck is not charging the battery; the speedo stays at zero and the OD button light remains off. The truck died on me when I was driving it last week. After going back the next day to pick it up, I installed a fully charged battery, it fired up and everything worked fine, I had OD, the battery was being charged, the speedo was working and the OD button light was on. Then after 5 minutes of driving I lost OD again, the speedo went flat, etc. etc.
I unscrewed the speedo cable at the tailshaft and taped the rounded off shaft and slid it back in, went for a test drive…no improvement.
I put the TPS back on…no improvement.
I stared into the engine bay for 15 minutes and whispered sweet nothings ...no improvement.
Next steps, remove the taped speedo sensor and replace with a new one. Check the voltage with the bad TPS on (will this really matter?).
Any recommendations?
I have the correct POT.
I’m using 18 gauge wire.
The red wire is in the center, I’ve tried switching sides on the 2 outside wires.
The truck is not charging the battery; the speedo stays at zero and the OD button light remains off. The truck died on me when I was driving it last week. After going back the next day to pick it up, I installed a fully charged battery, it fired up and everything worked fine, I had OD, the battery was being charged, the speedo was working and the OD button light was on. Then after 5 minutes of driving I lost OD again, the speedo went flat, etc. etc.
I unscrewed the speedo cable at the tailshaft and taped the rounded off shaft and slid it back in, went for a test drive…no improvement.
I put the TPS back on…no improvement.
I stared into the engine bay for 15 minutes and whispered sweet nothings ...no improvement.
Next steps, remove the taped speedo sensor and replace with a new one. Check the voltage with the bad TPS on (will this really matter?).
Any recommendations?