Why Tow Vehicle Charging Amps Low?

[ROBERT CROSS]

Originally Posted by dznf0g

Get one of these.

https://www.amazon.com/IPA-Tools-Inn...a-570352745245

The MacGyver in me...Valve grinding compound & Brakleen, followed by dielectric balm.😏

Bob
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[dznf0g]

Originally Posted by ROBERT CROSS

The MacGyver in me...Valve grinding compound & Brakleen, followed by dielectric balm.��

Bob
����
����

I feel ya, but I find those little tools to be really handy on the road. Just a couple of strokes with the appropriate end and you have shiny copper....ready to run in 60 seconds.

I really need to just end the issue with this: https://ezconnector.com/

But every time I go to shop, I get confused. There is really no clarity on which model to get for my truck. I'd like an OEM install...but then I read a bit about a plug and play "tee" model which keeps the traditional OEM socket and adds the EZ-connector. But which one for my truck? They really need an organized application chart. I can't tell crap from their pics.

[richard5933]

Originally Posted by ROBERT CROSS

The MacGyver in me...Valve grinding compound & Brakleen, followed by dielectric balm.😏

Bob
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🇺🇸

What are your thoughts about using conductive grease in place of the dielectric?

Seems like we're trying to increase conductivity here. I've been using a very thin film of this stuff on my shore cord blades and other similar things where I want to prevent corrosion and to help ensure a good connection:

https://www.sanchem.com/electrical-c...lubricant.html

[GCinSC2]

I know this is not from the OP's TV data but I was curious about this question and looked up my 2005 Dodge Ram 2500 charge line specs in my factory service manual.

My TV the fuse is #19 20A and the circuit A100 wire gauge is 14 to the charge line.

One POSSIBLE way to see the wire size sorta is to remove the cable at the connector to the 7 way plug and see if you can peak under the loom and determine wire size. Not a perfect option but it might offer info.

Gary

[ROBERT CROSS]

Originally Posted by richard5933

What are your thoughts about using conductive grease in place of the dielectric?

Seems like we're trying to increase conductivity here. I've been using a very thin film of this stuff on my shore cord blades and other similar things where I want to prevent corrosion and to help ensure a good connection:

https://www.sanchem.com/electrical-c...lubricant.html

Misnomer on my part...At home I actually use the messy stuff what gets all over everything when applied, it is a conductive goop (copper infused).

I keep this in the on-the-road kit.

Bob
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[jnm30327]

While a shorter wire , I also do not know the wire gauge of the Airstream side of the 7 way plug.

I guess I could open up the 12V distribution panel in the trailer and look. Unfortunately, I am 6'2" (with normal BMI.) Accessing that 12V distribution panel through the front storage door requires uncomfortable contortions.

[dznf0g]

Originally Posted by jnm30327

While a shorter wire , I also do not know the wire gauge of the Airstream side of the 7 way plug.



I guess I could open up the 12V distribution panel in the trailer and look. Unfortunately, I am 6'2" (with normal BMI.) Accessing that 12V distribution panel through the front storage door requires uncomfortable contortions.

I believe it to be 10ga. Mine was.

[GCinSC2]

AS 7 way cable wire sizes. Snip is from my AS wiring info.

Lights are 14ga
Brake blue 12ga
Battery pos black and neg white are 10ga

[dznf0g]

Originally Posted by GCinSC2

AS 7 way cable wire sizes. Snip is from my AS wiring info.



Lights are 14ga

Brake blue 12ga

Battery pos black and neg white are 10ga

I think that's industry standard. AS doesnt make umbilical cords.

[RedSHED]

Your alternator has an output curve. 170 A is rated current, and the rating is at a specified alternator temperature and pulley speed. "alternator output curves" is a usable search string.
Pulley ratios are gernerally in the 2 or 3 to 1 range, meaning the alternator is about 3x engine RPM.
A 170A alternator at 1k engine RPM and a high under hood temperature is likely producing about 100-120A, which should be plenty. Your basic vehicle consumption is probably 10-30A up to around 100-120 with lights, fan, heated seats, etc etc.

Alternator power is lower at low engine speeds and high alternator (under hood) temperatures. Temperature can affect output by 20% ish either way from rated power. (A 160 might be capable of 180 at -20F, for example).

But... the alternator output is likely tied into vehicle battery voltage. If voltage target is 14.4 (just pulling a number out of thin air) and trailer wants 14.5V to charge batteries, the alternator is likely to produce whatver is necessary to hold 14.4 where IT samples voltage and no more. IE, VBatt might be more like 14.35. Anyway this also would result in less current going to the trailer.

sdhqoffroad (first search result for me, prolly others are available) appears to sell aftermarket Tundra alternators up to about 270A rated (200A when hot). Interesting things start to happen at those kinds of currents on a vehicle. The field doesn't break down instantaneously and the effect of a suddenly dropped load could more like violently sloshing a 50 gal aquarium instead of a 5 gallon one.

[GCinSC2]

Originally Posted by dznf0g

I think that's industry standard. AS doesnt make umbilical cords.

Rich,

Bargman made my 2007 cable. I recently replaced and researched this question quite a bit. Found that the Hopkins 20048 11' cable matched color for color and gauge for gauge. But several other suppliers of cable didn't match our color/gauge config. The Hopkins 20048 has flat blade contacts and gets a pretty good purchase on the receptacle. My rig needed all of that 11' cable.

And this is not a direct note to the OP's query but a couple of weeks back at a small rally I got into a 7 way brake and charge line problem for another owner. Their OE duck bill plug had no ability to lock onto the 7 way receptacle. It pulled out (w/o cover holding it in) with light finger tip pull. I replaced the plug with a metal housing Pollak and that one needed a firm grip and good tug to get it out of the receptacle.


Folks, have you really inspected your 7 way connection lately?

Gary

[Fungus]

How would I determine the amperage that the 397-amp alternator in my F-250 is sending to the trailer?

[dznf0g]

Originally Posted by Fungus

How would I determine the amperage that the 397-amp alternator in my F-250 is sending to the trailer?

With an ammeter.

[wulfraat]

Originally Posted by Fungus

How would I determine the amperage that the 397-amp alternator in my F-250 is sending to the trailer?

Clamp an ammeter on the line or install a Bluetooth enabled dc-dc charger that reports out amperage.

[GCinSC2]

I can see charge line amps via my BMV-712. Its a pretty handy gizmo.

[wulfraat]

Originally Posted by GCinSC2;

I can see charge line amps via my BMV-712. Its a pretty handy gizmo.

BMV712 measures all inputs and all outputs from the batts if wired correctly - is not isolated to the current coming from the TV 12v constant hot

[GCinSC2]

Originally Posted by wulfraat

BMV712 measures all inputs and all outputs from the batts if wired correctly - is not isolated to the current coming from the TV 12v constant hot

So it’s seeing input vs output? Output while towing is parasitic plus fridge maybe .2-.3 amps?

[RedSHED]

Originally Posted by wulfraat

Clamp an ammeter on the line or install a Bluetooth enabled dc-dc charger that reports out amperage.

This. "Clamp" multimeters with both AC and DC are available. Measure current without having to physicallt tap into the circuit. Have used them, but do not own one ... yet. $30 ish on Am*z*n. Nuts, now I kinda want one.

Measuring current with something already in the system seems a little ... heisenbergian.

[dznf0g]

Originally Posted by RedSHED

This. "Clamp" multimeters with both AC and DC are available. Measure current without having to physicallt tap into the circuit. Have used them, but do not own one ... yet. $30 ish on Am*z*n. Nuts, now I kinda want one.

Measuring current with something already in the system seems a little ... heisenbergian.

They're nice, especially when you cant be at the tool for readings.

[GCinSC2]

BMV-712 Bluetooth connects to phone.

My rig is in backyard I get close open app and see voltage, current draw and more on the app connected to shore power or not.