This isn't a radio question but you were such great help last time I visited here maybe you can help me with this.

A buddy of mine has a big Ford diesel pickup. His overdrive keeps kicking in and out while pulling a trailer. He read about a fix for this problem and I said I would ask around. Everything is electronic on these vehicles these days even the accelerator pedal.

A signal goes from the accelerator position sensor via a wire to the on-board computer. Then to something on the transmission. The factory routed this wire somewhat close to the alternator and the wire picks up noise from the alternator. The fix he read about says to install a 2.2ufd cap from this wire to ground. This supposedly eliminates the noise. I guess it's the same theory as with noise in our radios. Filter caps to ground out any ripples etc.

What he doesn't know is if this cap is supposed to be an electrolytic or something else. I told him that with the radios anything above 1ufd that I have seen is usually an electrolytic. The voltage on this sensor wire in his truck ranges from +1.0 to +5.0 VDC depending on where the accelerator is.

This may be somewhat of a vague discription but I know nothing about these new electronic vehicles. Give me a good 'ol 65 chevy and I'll tell you how to make it scream.

Do you have any ideas that might help me to lead him in the right direction? Honestly I don't know. He says re-routing the wire, for whatever reason, is not an option.

Thanks,
Kirk

:This isn't a radio question but you were such great help last time I visited here maybe you can help me with this.
:
:A buddy of mine has a big Ford diesel pickup. His overdrive keeps kicking in and out while pulling a trailer. He read about a fix for this problem and I said I would ask around. Everything is electronic on these vehicles these days even the accelerator pedal.
:

Can he move the cable farther from the alternator?
:A signal goes from the accelerator position sensor via a wire to the on-board computer. Then to something on the transmission. The factory routed this wire somewhat close to the alternator and the wire picks up noise from the alternator. The fix he read about says to install a 2.2ufd cap from this wire to ground. This supposedly eliminates the noise. I guess it's the same theory as with noise in our radios. Filter caps to ground out any ripples etc.
:
:What he doesn't know is if this cap is supposed to be an electrolytic or something else. I told him that with the radios anything above 1ufd that I have seen is usually an electrolytic. The voltage on this sensor wire in his truck ranges from +1.0 to +5.0 VDC depending on where the accelerator is.
:
:This may be somewhat of a vague discription but I know nothing about these new electronic vehicles. Give me a good 'ol 65 chevy and I'll tell you how to make it scream.
:
:Do you have any ideas that might help me to lead him in the right direction? Honestly I don't know. He says re-routing the wire, for whatever reason, is not an option.
:
:Thanks,
:Kirk
:
:

::This isn't a radio question but you were such great help last time I visited here maybe you can help me with this.
::
::A buddy of mine has a big Ford diesel pickup. His overdrive keeps kicking in and out while pulling a trailer. He read about a fix for this problem and I said I would ask around. Everything is electronic on these vehicles these days even the accelerator pedal.
::
:
:
:
:Can he move the cable farther from the alternator?
::A signal goes from the accelerator position sensor via a wire to the on-board computer. Then to something on the transmission. The factory routed this wire somewhat close to the alternator and the wire picks up noise from the alternator. The fix he read about says to install a 2.2ufd cap from this wire to ground. This supposedly eliminates the noise. I guess it's the same theory as with noise in our radios. Filter caps to ground out any ripples etc.
::
::What he doesn't know is if this cap is supposed to be an electrolytic or something else. I told him that with the radios anything above 1ufd that I have seen is usually an electrolytic. The voltage on this sensor wire in his truck ranges from +1.0 to +5.0 VDC depending on where the accelerator is.
::
::This may be somewhat of a vague discription but I know nothing about these new electronic vehicles. Give me a good 'ol 65 chevy and I'll tell you how to make it scream.
::
::Do you have any ideas that might help me to lead him in the right direction? Honestly I don't know. He says re-routing the wire, for whatever reason, is not an option.
::
::Thanks,
::Kirk
::
::

Sorry-- posted in the wrong section. Can he move the cable farther from the alternator?

the key is pulling a trailer. the same alternator noise would be there whether pulling a trailer or not. i was always told that overdrive should not be used when towing because of the fact it WILL switch in and out of overdrive due to the changes in apparent load and speed on hills etc. i may be totally off base but i dont think the alternator is the issue. not to mention switching the trans in and out of overdrive that much has to be beating the crap out of it.

:This isn't a radio question but you were such great help last time I visited here maybe you can help me with this.
:
:A buddy of mine has a big Ford diesel pickup. His overdrive keeps kicking in and out while pulling a trailer. He read about a fix for this problem and I said I would ask around. Everything is electronic on these vehicles these days even the accelerator pedal.
:
:A signal goes from the accelerator position sensor via a wire to the on-board computer. Then to something on the transmission. The factory routed this wire somewhat close to the alternator and the wire picks up noise from the alternator. The fix he read about says to install a 2.2ufd cap from this wire to ground. This supposedly eliminates the noise. I guess it's the same theory as with noise in our radios. Filter caps to ground out any ripples etc.
:
:What he doesn't know is if this cap is supposed to be an electrolytic or something else. I told him that with the radios anything above 1ufd that I have seen is usually an electrolytic. The voltage on this sensor wire in his truck ranges from +1.0 to +5.0 VDC depending on where the accelerator is.
:
:This may be somewhat of a vague discription but I know nothing about these new electronic vehicles. Give me a good 'ol 65 chevy and I'll tell you how to make it scream.
:
:Do you have any ideas that might help me to lead him in the right direction? Honestly I don't know. He says re-routing the wire, for whatever reason, is not an option.
:
:Thanks,
:Kirk
:
:

Kirk,
Think DTIN is right. My owner's manual says to override the OD when climbing mountain w/wo a load if the same symptoms occur. Also think manifold vacuum (intake) and RPM (tach) may also have an effect on the down shifts. A 2.2 mf cap or close from Radio Shack would be cheap enough though, but just finding a way to install it might be tough. Another choice is to tightly wrap the wire with alum foil where it passes the alternator, then tie the foil to a good ground.

marv

:the key is pulling a trailer. the same alternator noise would be there whether pulling a trailer or not. i was always told that overdrive should not be used when towing because of the fact it WILL switch in and out of overdrive due to the changes in apparent load and speed on hills etc. i may be totally off base but i dont think the alternator is the issue. not to mention switching the trans in and out of overdrive that much has to be beating the crap out of it.
:
::This isn't a radio question but you were such great help last time I visited here maybe you can help me with this.
::
::A buddy of mine has a big Ford diesel pickup. His overdrive keeps kicking in and out while pulling a trailer. He read about a fix for this problem and I said I would ask around. Everything is electronic on these vehicles these days even the accelerator pedal.
::
::A signal goes from the accelerator position sensor via a wire to the on-board computer. Then to something on the transmission. The factory routed this wire somewhat close to the alternator and the wire picks up noise from the alternator. The fix he read about says to install a 2.2ufd cap from this wire to ground. This supposedly eliminates the noise. I guess it's the same theory as with noise in our radios. Filter caps to ground out any ripples etc.
::
::What he doesn't know is if this cap is supposed to be an electrolytic or something else. I told him that with the radios anything above 1ufd that I have seen is usually an electrolytic. The voltage on this sensor wire in his truck ranges from +1.0 to +5.0 VDC depending on where the accelerator is.
::
::This may be somewhat of a vague discription but I know nothing about these new electronic vehicles. Give me a good 'ol 65 chevy and I'll tell you how to make it scream.
::
::Do you have any ideas that might help me to lead him in the right direction? Honestly I don't know. He says re-routing the wire, for whatever reason, is not an option.
::
::Thanks,
::Kirk
::
::

:the key is pulling a trailer. the same alternator noise would be there whether pulling a trailer or not. i was always told that overdrive should not be used when towing because of the fact it WILL switch in and out of overdrive due to the changes in apparent load and speed on hills etc. i may be totally off base but i dont think the alternator is the issue. not to mention switching the trans in and out of overdrive that much has to be beating the crap out of it.
:
::This isn't a radio question but you were such great help last time I visited here maybe you can help me with this.
::
::A buddy of mine has a big Ford diesel pickup. His overdrive keeps kicking in and out while pulling a trailer. He read about a fix for this problem and I said I would ask around. Everything is electronic on these vehicles these days even the accelerator pedal.
::
::A signal goes from the accelerator position sensor via a wire to the on-board computer. Then to something on the transmission. The factory routed this wire somewhat close to the alternator and the wire picks up noise from the alternator. The fix he read about says to install a 2.2ufd cap from this wire to ground. This supposedly eliminates the noise. I guess it's the same theory as with noise in our radios. Filter caps to ground out any ripples etc.
::
::What he doesn't know is if this cap is supposed to be an electrolytic or something else. I told him that with the radios anything above 1ufd that I have seen is usually an electrolytic. The voltage on this sensor wire in his truck ranges from +1.0 to +5.0 VDC depending on where the accelerator is.
::
::This may be somewhat of a vague discription but I know nothing about these new electronic vehicles. Give me a good 'ol 65 chevy and I'll tell you how to make it scream.
::
::Do you have any ideas that might help me to lead him in the right direction? Honestly I don't know. He says re-routing the wire, for whatever reason, is not an option.
::
::Thanks,
::Kirk
::
::
:
:Hi! Kirk,
Does it make a difference if the air conditioning is on or off? I have seen A/C clutches kicking in and out at highway speeds that felt like the trans was shifting.If it is the trans. shifting, the vehicle could be on a very slight uphill grade and this would be normal.Even roads that look flat have some rise and fall to them.Is the capacitor repair recommended by the factory or dealer? If not,I would shy away from it.Also, check the owner's manual to see what load can be pulled in overdrive because at one time Ford did not recommend using overdrive with more than 50% rated load.I also found increase fuel economy by staying out of overdrive,while pulling heavy loads,even though the engine rpm's were higher.I have never seen a problem with wire routing in a circuit operating at 1v to 5v.If it is a problem common to that vehicle, the dealer should have a factory technical service bulletin (TSB) on it.To me it sounds like normal shifting .
Bob Masse
:
:

I, too, am dubious this is an electrical noise problem - since it only occurs when pulling a trailer.

Also, I'm wondering if an alternator should be expected to cause significant electrical noise. That is an AC machine - not commutated like the old DC generators.

But back to your question: I think either an e-cap or film cap might be OK. But, I would tend toward a film cap - a 2.2-uF film cap, rated at, say, 50V, shouldn't be too large, physically. But, I do wonder about the 2.2-uF value. Most electrical noise is composed of high frequency components, and I would have expected a lower value cap. Double check that.
Doug

::the key is pulling a trailer. the same alternator noise would be there whether pulling a trailer or not. i was always told that overdrive should not be used when towing because of the fact it WILL switch in and out of overdrive due to the changes in apparent load and speed on hills etc. i may be totally off base but i dont think the alternator is the issue. not to mention switching the trans in and out of overdrive that much has to be beating the crap out of it.
::
:::This isn't a radio question but you were such great help last time I visited here maybe you can help me with this.
:::
:::A buddy of mine has a big Ford diesel pickup. His overdrive keeps kicking in and out while pulling a trailer. He read about a fix for this problem and I said I would ask around. Everything is electronic on these vehicles these days even the accelerator pedal.
:::
:::A signal goes from the accelerator position sensor via a wire to the on-board computer. Then to something on the transmission. The factory routed this wire somewhat close to the alternator and the wire picks up noise from the alternator. The fix he read about says to install a 2.2ufd cap from this wire to ground. This supposedly eliminates the noise. I guess it's the same theory as with noise in our radios. Filter caps to ground out any ripples etc.
:::
:::What he doesn't know is if this cap is supposed to be an electrolytic or something else. I told him that with the radios anything above 1ufd that I have seen is usually an electrolytic. The voltage on this sensor wire in his truck ranges from +1.0 to +5.0 VDC depending on where the accelerator is.
:::
:::This may be somewhat of a vague discription but I know nothing about these new electronic vehicles. Give me a good 'ol 65 chevy and I'll tell you how to make it scream.
:::
:::Do you have any ideas that might help me to lead him in the right direction? Honestly I don't know. He says re-routing the wire, for whatever reason, is not an option.
:::
:::Thanks,
:::Kirk
:::
:::
::
::Hi! Kirk,
: Does it make a difference if the air conditioning is on or off? I have seen A/C clutches kicking in and out at highway speeds that felt like the trans was shifting.If it is the trans. shifting, the vehicle could be on a very slight uphill grade and this would be normal.Even roads that look flat have some rise and fall to them.Is the capacitor repair recommended by the factory or dealer? If not,I would shy away from it.Also, check the owner's manual to see what load can be pulled in overdrive because at one time Ford did not recommend using overdrive with more than 50% rated load.I also found increase fuel economy by staying out of overdrive,while pulling heavy loads,even though the engine rpm's were higher.I have never seen a problem with wire routing in a circuit operating at 1v to 5v.If it is a problem common to that vehicle, the dealer should have a factory technical service bulletin (TSB) on it.To me it sounds like normal shifting .
: Bob Masse
::
::
:Just one more note.Caution on delaying the downshift from overdrive.The overdrive clutch is the hardest working clutch in an automatic transmission and overworking it will cause it to fail prematurely.When pulling heavy loads, an early downshift is preferred.This actually saves fuel.When you load a gasoline engine down heavily, the engine vacuum drops to 0" and that along with low rpm forces the fuel injection system into full enrichment mode. That is not efficient. Bob Masse
:
:

To add a capacitor is to make a slower rise and fall to the sensor unit. By doing so will make a delay from falling out of overdrive. It will still shift when it needs to, but not as much of that in & out all the time.
It's best if you are pulling any hill with a load to shift out of overdrive, and keep the RPM down as to only do the speed limit.

:To add a capacitor is to make a slower rise and fall to the sensor unit. By doing so will make a delay from falling out of overdrive. It will still shift when it needs to, but not as much of that in & out all the time.
:It's best if you are pulling any hill with a load to shift out of overdrive, and keep the RPM down as to only do the speed limit.
:
:
:Wow! I'm sorry I don't know the answers to most of your questions. I know nothing about these newer vehicles. It's my understanding that the manufacturer, in this case Chrysler Dodge, has recommended this fix in some kind of service bulletin. Also I'm told that rerouting the wiring is not an option. I printed your comments and gave them to this guy and he tells me that it's not actually the overdrive but something in the torque converter that is actually shifting and this affects the overdrive. I'm an old school mechanic and I've never heard of a torque converter shifting but he tells me that torque converters are a bit different then they used to be. I think he wants to try the capacitor (2.2ufd) suggestion from Chrysler and see what happens. Along with this you're supposed to "re-flash" something in the vehicles computer which he is capable of doing. All greek to me. Years ago when 2400 baud modems were the latest thing we used to re-flash the built-in ROM, read only memory, chip with updated codes as upgrades became available. I know that alternator noise can affect the radio in a vehicle (an older vehicle) if one or more of the diodes is weak or bad.

Well he has all this info so I'm gonna let him run with it and just see what happens. I'll get back to you when he tells me what the results are.

Appreciate all the input,
Kirk

::To add a capacitor is to make a slower rise and fall to the sensor unit. By doing so will make a delay from falling out of overdrive. It will still shift when it needs to, but not as much of that in & out all the time.
::It's best if you are pulling any hill with a load to shift out of overdrive, and keep the RPM down as to only do the speed limit.
::
::
::Wow! I'm sorry I don't know the answers to most of your questions. I know nothing about these newer vehicles. It's my understanding that the manufacturer, in this case Chrysler Dodge, has recommended this fix in some kind of service bulletin. Also I'm told that rerouting the wiring is not an option. I printed your comments and gave them to this guy and he tells me that it's not actually the overdrive but something in the torque converter that is actually shifting and this affects the overdrive. I'm an old school mechanic and I've never heard of a torque converter shifting but he tells me that torque converters are a bit different then they used to be. I think he wants to try the capacitor (2.2ufd) suggestion from Chrysler and see what happens. Along with this you're supposed to "re-flash" something in the vehicles computer which he is capable of doing. All greek to me. Years ago when 2400 baud modems were the latest thing we used to re-flash the built-in ROM, read only memory, chip with updated codes as upgrades became available. I know that alternator noise can affect the radio in a vehicle (an older vehicle) if one or more of the diodes is weak or bad.
:
:Well he has all this info so I'm gonna let him run with it and just see what happens. I'll get back to you when he tells me what the results are.
:
:Appreciate all the input,
:Kirk
;
:
: I'm wondering why he is taking a Ford to a Chrysler dealer. As far as the torque convertor,it is a lock up torque convertor.It has a computer controlled clutch in it that locks it up solid,for fuel economy, when conditions are correct to do so.Delaying the unlock of the torque convertor can cause torque convertor chatter which is a horrible vibration that makes you think it is about to self destruct.The torque convertor has to lock and unlock according to driving conditions and that is normal.Most vehicles only exhibit a 200 rpm change during this process .If the vehicle doesn't surge radically or do some strange gear hunting(shifting up and down)during the lock-unlock cycle it is working normally. Lock up torque convertors are nothing new and I remember seeing them in the early 80's.Hope this helps. Bob Masse
;
: