MH not charging towed. New Dilemma

[RJL1]

We've been towing our 2010 Jeep JKUR for the last couple of seasons behind our 2010 Damon Challenger 368. Never a problem with the battery. We have a brake buddy and a charging cord. This last trip to SW Fla from S NJ our Jeep was totally dead at our first stop in SC. Got it jumped and died again when we arrived in Fla for our second night. Charged it all night, made it to our our place in Cape Coral and bought a multimeter. Never used one before. My question is, is there a tow specific fuse in the MH that's used to charge a towed? I'm gonna pick at this issue as we'll be here for a month. Just need some expert advise from the folks here.

Thanks in advance

Bob

[THenne1713]

1) Toad wiring can be factory 4-pin, or FACTORY 7-pin, or field wired, but generally involves fuses, and IGN controlled relay to the B+ line. 2) Blown fuses generally are caused by WIRING DAMAGE in the TOW harness, 3) so START there, locate/ repair any damage, and THEN 4) look for a blown fuse? LUCK TO YA. p.s. If you find no tow harness damage, check TOAD wiring?

[l1v3fr33ord1]

Bob-

Since you are new to multimeters and tow wiring, a place to start is by looking at the diagrams here:

https://www.etrailer.com/faq-wiring.aspx

Looking at the "vehicle-side" (that is, motorhome) hitch connector:

Six-pin: 12V on center pin, ground on two o'clock pin
Seven-pin: 12V on one o'clock blade, ground on seven o'clock blade

With the motorhome engine off:

1) Set the multimeter for DC volts
2) Touch one probe to the 12V pin/blade and the other to the ground pin/blade (see warning below)
3) See what the meter reads

Repeat above with the engine running.

If no 12V either case, then something has failed upstream, such as a fuse.

Warning: Be careful not to accidentally touch a probe to both 12V and ground pins/blades at the same time. That could cause a short, blowing a charge line fuse.

Report back your results, and we'll go from there.

Note: It's always possible your coach has a non-standard connector or wiring to provide the charge line.

By the way, does your Challenger sit on a Ford or Workhorse chassis?

[RJL1]

Originally Posted by l1v3fr33ord1

Bob-

Since you are new to multimeters and tow wiring, a place to start is by looking at the diagrams here:

https://www.etrailer.com/faq-wiring.aspx

Looking at the "vehicle-side" (that is, motorhome) hitch connector:

Six-pin: 12V on center pin, ground on two o'clock pin
Seven-pin: 12V on one o'clock blade, ground on seven o'clock blade

With the motorhome engine off:

1) Set the multimeter for DC volts
2) Touch one probe to the 12V pin/blade and the other to the ground pin/blade (see warning below)
3) See what the meter reads

Repeat above with the engine running.

If no 12V either case, then something has failed upstream, such as a fuse.

Warning: Be careful not to accidentally touch a probe to both 12V and ground pins/blades at the same time. That could cause a short, blowing a charge line fuse.

Report back your results, and we'll go from there.

Note: It's always possible your coach has a non-standard connector or wiring to provide the charge line.

By the way, does your Challenger sit on a Ford or Workhorse chassis?

Thank you for the detailed post, Mark. OK. So I checked the voltage on the MH with it running at the 7 pin outlet, read 13.5 or so. Connected the charging cord to the MH, checked the end of the charging cord at the 6 pin connector, same power reading, 13.5 or so.

Started the Jeep, tested the battery, read 14.5 or so, connected the cord to the Jeep, no change on the Jeep end. I'm assuming it's a fuse at the Jeep end now. Now Just to find it.

My rig is on the F53 chassis.

Thanks again,

Bob

[RJL1]

Wanted to give an update should anyone in the future have an issue like this. The rear of the plug on the Jeep was corroded to the point that the charging wire had broken off.

Replaced it the other day but I still have to hook it up to the MH to ensure it's in fact charging and is wired correctly. I'm pretty sure it is.

Also, no inline fuse.

Thank you for the help all

Bob