Ford chassis class a wire color

[dabrooks]

Here is a photo of the fuse legend. Module G the number 4 fuse is trailer power. I was mistaken it is a 20 amp fuse not a 30 amp.

[Bonzoso]

Originally Posted by dabrooks

Attachment 393446

Here is a photo of the fuse legend. Module G the number 4 fuse is trailer power. I was mistaken it is a 20 amp fuse not a 30 amp.

So that looks like it comes off your house batteries. Was that the way your unit came from the builder? Thanks! Looks like I'm going to have to look into providing 12v mot just for the extender but I had to get a new battery for my Grand cherokee toad because it's voltage was too low for my RVibrake3 system. I'm going to have to make sure my toad battery stays charged. I'm learning new stuff all the time. Thanks again!

[dabrooks]

Yes that was from the Tiffin house fuse block. What year chassis do you have? We have a 2013 and I have the legend for the Ford fuse block which is under the dash to the left of the steering wheel. There are several fuses for the "body builder" marked for trailer leads. Mostly turns signals, brake controller and the like. There is one labeled 20amp 12volt power.

The legend is 3 pages I can post it if you think it would help.

[l1v3fr33ord1]

Bonzoso-

Now that you've got two problems to solve, I'll offer suggestions.

1) TPMS extender
I'm surprised that on a coach as short as yours that you need an extender. Have you tried using the system without one? If you have, and are convinced one is needed, then you should look for an unswitched 12V source off the house battery bank. Usually this means a wire that feeds a 12V light, but one that does not have an upstream switch. Other options on some coaches are the refrigerator 12V or propane detector 12V.

My 31-foot coach did not need an extender. I was surprised as to how far the toad transmitters could transmit.

2) 12V Toad Charge Line
If you plan to flat tow, and not use a trailer, then you can repurpose the trailer electric brake controller wire (also known as "the blue wire") to feed 12V from the chassis battery to the toad. That wire runs from below the dash to the trailer hitch connector, terminating on a different pin (5 o'clock) than the "standard" 12V charge line (1 o'clock) (see this link, "Vehicle Side 7-Way/7-Way RV Standard"). The plus of using this wire is it's usually sized (12 or 14 AWG) and fused (30A) for high current.

Notes:
a) On the wired end of the toad connector, you will wire the trailer electric brake controller wire to your toad's battery, rather than using the "standard" 12V charge line wire.
b) You will install a fuse in this wire, as close to the toad battery as possible.
c) I recommend a 15A fuse for this, and also replacing the Ford-supplied 30A fuse with a 15A fuse.
d) Why down-rate the 30A circuit to 15A? because I suspect the wire size in the umbilical is less than 12 AWG.
e) Why use fuses instead of auto-reset circuit breakers? In at least one case described on iRV2, a circuit breaker caused a toad fire.
f) You'll cross-connect the Ford-supplied 12V trailer electric brake controller power wire to the trailer electric brake controller output signal wire. The easiest way to do this is to purchase a pigtail that plugs into the trailer electric brake controller connector that Ford provides under the dash. A suitable pigtail is the Tekonsha 3035-P, link here. Cut off the Tekonsha end and splice the black wire to the blue wire.
g) This method is completely plug-and-play and reversible. Should you want to tow a trailer, simply unlpug the customized pigtail and replace it with a 3035-P connected to the same connector under the dash. Oh, and put a 30A fuse in place of the 15A fuse, so it's back to factory spec.
h) Important: Wired this way, the circuit from the chassis battery to the coach hitch connector is "always hot." It is not ignition-switched. That means as soon as you plug in the umbilical, it's "hot," and then plugging the toad end of the umbilical into the toad completes the connection between the coach and toad batteries. I'm sure you can work through the implications of this design. If you want an ignition-switched charge line using this design, then you would wire the pigtail with a relay between the blue and black wires, and then activate the relay with an ignition-switch signal from a fuse off the under-dash panel, of which there should be a couple open for use.

On a different topic, you should add a "signature" to your profile. It contains whatever info you want; most people put info about their coach there, so they don't have to type it into each message. Instructions for adding a signature are here.

[Bonzoso]

Originally Posted by l1v3fr33ord1

Bonzoso-

Now that you've got two problems to solve, I'll offer suggestions.

1) TPMS extender
I'm surprised that on a coach as short as yours that you need an extender. Have you tried using the system without one? If you have, and are convinced one is needed, then you should look for an unswitched 12V source off the house battery bank. Usually this means a wire that feeds a 12V light, but one that does not have an upstream switch. Other options on some coaches are the refrigerator 12V or propane detector 12V.

My 31-foot coach did not need an extender. I was surprised as to how far the toad transmitters could transmit.

2) 12V Toad Charge Line
If you plan to flat tow, and not use a trailer, then you can repurpose the trailer electric brake controller wire (also known as "the blue wire") to feed 12V from the chassis battery to the toad. That wire runs from below the dash to the trailer hitch connector, terminating on a different pin (5 o'clock) than the "standard" 12V charge line (1 o'clock) (see this link, "Vehicle Side 7-Way/7-Way RV Standard"). The plus of using this wire is it's usually sized (12 or 14 AWG) and fused (30A) for high current.

Notes:
a) On the wired end of the toad connector, you will wire the trailer electric brake controller wire to your toad's battery, rather than using the "standard" 12V charge line wire.
b) You will install a fuse in this wire, as close to the toad battery as possible.
c) I recommend a 15A fuse for this, and also replacing the Ford-supplied 30A fuse with a 15A fuse.
d) Why down-rate the 30A circuit to 15A? because I suspect the wire size in the umbilical is less than 12 AWG.
e) Why use fuses instead of auto-reset circuit breakers? In at least one case described on iRV2, a circuit breaker caused a toad fire.
f) You'll cross-connect the Ford-supplied 12V trailer electric brake controller power wire to the trailer electric brake controller output signal wire. The easiest way to do this is to purchase a pigtail that plugs into the trailer electric brake controller connector that Ford provides under the dash. A suitable pigtail is the Tekonsha 3035-P, link here. Cut off the Tekonsha end and splice the black wire to the blue wire.
g) This method is completely plug-and-play and reversible. Should you want to tow a trailer, simply unlpug the customized pigtail and replace it with a 3035-P connected to the same connector under the dash. Oh, and put a 30A fuse in place of the 15A fuse, so it's back to factory spec.
h) Important: Wired this way, the circuit from the chassis battery to the coach hitch connector is "always hot." It is not ignition-switched. That means as soon as you plug in the umbilical, it's "hot," and then plugging the toad end of the umbilical into the toad completes the connection between the coach and toad batteries. I'm sure you can work through the implications of this design. If you want an ignition-switched charge line using this design, then you would wire the pigtail with a relay between the blue and black wires, and then activate the relay with an ignition-switch signal from a fuse off the under-dash panel, of which there should be a couple open for use.

On a different topic, you should add a "signature" to your profile. It contains whatever info you want; most people put info about their coach there, so they don't have to type it into each message. Instructions for adding a signature are here.

I used the extender because it was suggested by the manufacturer. Ran a 14g wire from house batteries to the back where I mounted the extender. I managed to make the 4 hr drive here to the campground in Cedar Run PA without seriously draining the battery with my RVibrake3 in my old ZJ. I will take your info to run a charge line for the toad. Thanks so much!

[Bonzoso]

Originally Posted by dabrooks

Yes that was from the Tiffin house fuse block. What year chassis do you have? We have a 2013 and I have the legend for the Ford fuse block which is under the dash to the left of the steering wheel. There are several fuses for the "body builder" marked for trailer leads. Mostly turns signals, brake controller and the like. There is one labeled 20amp 12volt power.

The legend is 3 pages I can post it if you think it would help.

Thanks D&C, We got to our campsite yesterday without issue. We Have a 2017 f53 chassis on our Coachmen Pursuit. Unfortunately Coachmen (Forest River) manual gives no Fuse info. I do have the Ford Chassis owners manual but it doesn't show any fuse indicating a 12v line to hitch plug. Once I get back home I'll give this issue some more thought with the many responses I've gotten. Thanks to you and all other responders.

[PS89]

We Have a 2017 f53 chassis

Well, since you finally specifically identified your chassis' model year (should have done that in your first post), it's now possible to provide specific information regarding the Ford portion of the system.

but it doesn't show any fuse indicating a 12v line to hitch plug

There isn't one. PDB fuse F13 is a 30A circuit that feeds into the TBC module as shown in the diagram below. After that, it's up to Coachman as well as the selected TBC module vendor. Sorry, don't have Coachman info, just Ford manuals.

[Bonzoso]

Originally Posted by PS89

Well, since you finally specifically identified your chassis' model year (should have done that in your first post), it's now possible to provide specific information regarding the Ford portion of the system.

Sorry PS89 that my posting annoyed you so much that you needed to reprimand me. My original post was to a Ford chassis section and it didn't occur to me that one needed to be Manufacture specific. No other members that replied seemed to be put out by my question. Please take a chill pill and be more friendly. I don't need your input that badly.

[chboone]

Late to the party. When I installed the extender I installed it in the closet next the rear bed and tapped into the power for the light next to the bed.

[HarryStone]

Originally Posted by Bonzoso

Sorry PS89 that my posting annoyed you so much that you needed to reprimand me. My original post was to a Ford chassis section and it didn't occur to me that one needed to be Manufacture specific. No other members that replied seemed to be put out by my question. Please take a chill pill and be more friendly. I don't need your input that badly.

He didn't say you needed to put the manufacturer, he said you should have included the YEAR it was manufactured.

[PS89]

Originally Posted by HarryStone

He didn't say you needed to put the manufacturer, he said you should have included the YEAR it was manufactured.

Indeed. It is impossible to look up accurate technical information without first knowing in which volume the information needs to come from. The F53 chassis has been in production for over 25 years and there have been multiple electrical system generations.


My point is that, when requesting technical information, you MUST adequately identify what is being worked on.