electrically challenged question about switch amps

[dc4]

Well i went and bought some switches to add to my truck, one for the running lights, 1 for the high idle, and 1 for the battery protect mode. The wire that is supplying the power is running off a 10 amp fuse, all my switches are 20 amp, cant seem to find any 10 amp switches that dont look cheesy. Will I be alright if I put a switch that can handle 20 amps,, i figured it would be alright but I just wanted to check with you guys.

[ZeroOne]

Originally Posted by dc4

Well i went and bought some switches to add to my truck, one for the running lights, 1 for the high idle, and 1 for the battery protect mode. The wire that is supplying the power is running off a 10 amp fuse, all my switches are 20 amp, cant seem to find any 10 amp switches that dont look cheesy. Will I be alright if I put a switch that can handle 20 amps,, i figured it would be alright but I just wanted to check with you guys.

Your circuit is 10A and switch is capable of handling up to 20A? If I read that right, the switch will be fine. Keep in mind though, that you are still limited in current to the 10A that you are supplying power with. So, around 120 watts total. (12V x 10A = 120W).

[dc4]

Originally Posted by ZeroOne

Your circuit is 10A and switch is capable of handling up to 20A? If I read that right, the switch will be fine. Keep in mind though, that you are still limited in current to the 10A that you are supplying power with. So, around 120 watts total. (12V x 10A = 120W).

thanks thats exactlywhat I was looking for, I have one other question

https://www.fleet.ford.com/truckBBAS...tml/Q162R1.pdf

on pg 11
I did the high idle mod but i want to add a potentiometer, after looking at that diagram it show the green pto_rpm wire being grounded which I understand but what I dont understand is it says pwr grd 4.75k, what does the 4.75k mean, do i need to add something to the ground or something

[ZeroOne]

Originally Posted by dc4

thanks thats exactlywhat I was looking for, I have one other question

https://www.fleet.ford.com/truckBBAS...tml/Q162R1.pdf

on pg 11
I did the high idle mod but i want to add a potentiometer, after looking at that diagram it show the green pto_rpm wire being grounded which I understand but what I dont understand is it says pwr grd 4.75k, what does the 4.75k mean, do i need to add something to the ground or something

For some reason, when I click your link, the ford site defaults to a front-page.

You want to add a potentiometer (pot)? So you're wanting to adjust the high idle speed with a dial and not just have the default 1,200rpm?

This gets a bit more complicated but isn't terrible. Refer to page 11 of your link. ( https://www.fleet.ford.com/truckBBAS...tml/Q162R1.pdf )

The pot in the diagram is in the center... it has 3 wires going to it. By the looks of page 11, you need the white/brown wire (PTO-VREF), green (PTO-RPM), and gray/violet (PTO-GND).

The 4.75k looks like an internal resistor/ground connection. Keep in mind that the dotted line surrounding all of that is labeled "Ford PCM", so it appears that is inside the PCM and nothing for you to deal with.

It looks like you connect the PTO-VREF (just a 5 volt lead for rpm selection) to the pot, then connect PTO-GND to the other side. The middle connection on the pot will be the green PTO-RPM wire. With these 3 wires, it makes the positive, ground, and speed selection setup for your dial (pot). If you REALLY want to get fancy, you can use the blue/white wire (PTO-OK) to hook up an LED to indicate whether its in high idle or not. Though... not needed.

[ZeroOne]

I'm not sure how familiar you are with potentiometers, but here is a quick wiki to see what they are and how they work.

Potentiometer - Wikipedia, the free encyclopedia

[ZeroOne]

Just wanted to reiterate... the dotted lines in that pdf on page 11 show that the ford PCM is on the right. That stuff is internal. The center section (not within a dotted line) are the blunt cut wires that you see under the dash. The section to the left, labeled "Provided by aftermarket body builder" are the connections you will be making. So, just the 3 connections at the pot.

If you were doing just a resistor, you'd only use the PTO-VREF and PTO-RPM wires connected together. That is displayed just to the left of the potentiometer connections.

[dc4]

Originally Posted by ZeroOne

For some reason, when I click your link, the ford site defaults to a front-page.

You want to add a potentiometer (pot)? So you're wanting to adjust the high idle speed with a dial and not just have the default 1,200rpm?

This gets a bit more complicated but isn't terrible. Refer to page 11 of your link. ( https://www.fleet.ford.com/truckBBAS...tml/Q162R1.pdf )

The pot in the diagram is in the center... it has 3 wires going to it. By the looks of page 11, you need the white/brown wire (PTO-VREF), green (PTO-RPM), and gray/violet (PTO-GND).

The 4.75k looks like an internal resistor/ground connection. Keep in mind that the dotted line surrounding all of that is labeled "Ford PCM", so it appears that is inside the PCM and nothing for you to deal with.

It looks like you connect the PTO-VREF (just a 5 volt lead for rpm selection) to the pot, then connect PTO-GND to the other side. The middle connection on the pot will be the green PTO-RPM wire. With these 3 wires, it makes the positive, ground, and speed selection setup for your dial (pot). If you REALLY want to get fancy, you can use the blue/white wire (PTO-OK) to hook up an LED to indicate whether its in high idle or not. Though... not needed.

Man thanks for pointing that out i was going crazy trying to figure out what that 4.75k was all about, glad its in the pcm and I dont have to worry about it. I bought a potentiometer from radioshak but I think I may have to get another one, it has 5 prongs on it and it looks like i only need 3, im sure i could probably still use it id just have to find a diagram that shows which prongs to use. Thanks for all your help. Ill get through this damn potentiometer one day, hopefully soon, been driving me crazy but Ive learned a lot and it is kinda fun messing around with it

[ZeroOne]

No problem! You have me curious now too. Might be something to mess with one of these days. I don't know a lot about potentiometers so I'm not 100% sure you can't use the one you got... but that would take some googling to see how a 5-prong works.

[ZeroOne]

Here ya go.... see you back here in a few days! LOL

Potentiometers (Beginners' Guide to Pots)

[ZeroOne]

WOW, almost forgot the most important part. The range for the pot needs to be from 43k-ohms (1,200 rpm) up to .510k-ohms (2400 rpm), if I read correctly elsewhere. So that means you need to get a 50K-ohm pot.

Something resembling this, though you should be able to find one that has a nice housing or something and not just a plain old pot. Also, it needs a 1 watt rating. Not a half watt, as the one in the link has.... though I'm not sure that part is crazy-important, if you can't find one.

50K-Ohm Linear-Taper Potentiometer - RadioShack.com