Omni charge line

chunker21 · 07-10-2021, 03:40 PM

I did a searching no results. Talking about the 12v charge line that should be coming off the coach trailer connector at the 1 o'clock position on the 7 pole connector. I checked the connector and all positions work as advertised except the one which should have the 12v charge. I removed the connector and there is a large gauge orange wire, 12 or 10, connected to that position on the plug, but no 12v there. I looked in the engine compartment and no obvious unused wire, orange or other color. I know I'm not the first to encounter this so hopefully someone can point it to me.

The orange wire enters a loom/conduit and heads forward. I haven't started tracing yet and that's the next step. Thanks in advance for help.

**EA37TS** · 07-10-2021, 03:44 PM

Did you check the fuses, and yes there should be one in one of the various fuse boxes.

Many discussions on this topic on the forum to include specific fuse f-numbers to look for so a search should provide additional info.

chunker21 · 07-10-2021, 03:53 PM

Quote:

Originally Posted by EA37TS

Did you check the fuses, and yes there should be one in one of the various fuse boxes.

Many discussions on this topic on the forum to include specific fuse f-numbers to look for so a search should provide additional info.

I went to the battery compartment under the steps and I found a similar orange wire going to a fuze, 20 amp, then to a bus bar (BIM, BAM, ???). That bus has a red + cable, looks like battery type and several others. I'll look at the chassis fuzes and see if something missing up there.

**EA37TS** · 07-10-2021, 04:00 PM

Quote:

Originally Posted by chunker21

I went to the battery compartment under the steps and I found a similar orange wire going to a fuze, 20 amp, then to a bus bar (BIM, BAM, ???). That bus has a red + cable, looks like battery type and several others. I'll look at the chassis fuzes and see if something missing up there.

There should also be a Power Distribution Center (fuse box) installed by Ford or Thor. That is normally where all the fuses and relays for the 7 pin are located. You will have multipole fuses and relays tor power, directional signals, brake lights, etc...

The fuse for pin 4 is usually a 30amp fuse and often times is not labelled correctly or labelled to where it is easily identified.

chunker21 · 07-10-2021, 04:22 PM

Quote:

Originally Posted by EA37TS

There should also be a Power Distribution Center (fuse box) installed by Ford or Thor. That is normally where all the fuses and relays for the 7 pin are located. You will have multipole fuses and relays tor power, directional signals, brake lights, etc...

The fuse for pin 4 is usually a 30amp fuse and often times is not labelled correctly or labelled to where it is easily identified.

I went to the owner's manual and the fuze diagrams. In the Ford main fuze box are 2 positions, 7 & 26, labeled "trailer tow battery charge" both 30amp and both good as checked by an ohm meter. When I checked the 7 pole connection, I checked with the ignition on and also engine running. Next check will be remove the fuzes and check the fuze box positions for voltage passing through. I didn't check the 30amp fuze in the battery box for continuity but will next trip out. I'm also going to check voltage passing through/to the remote 30amp fuse connecter on the battery section.

**EA37TS** · 07-10-2021, 05:04 PM

Quote:

Originally Posted by chunker21

I went to the owner's manual and the fuze diagrams. In the Ford main fuze box are 2 positions, 7 & 26, labeled "trailer tow battery charge" both 30amp and both good as checked by an ohm meter. When I checked the 7 pole connection, I checked with the ignition on and also engine running. Next check will be remove the fuzes and check the fuze box positions for voltage passing through. I didn't check the 30amp fuze in the battery box for continuity but will next trip out. I'm also going to check voltage passing through/to the remote 30amp fuse connecter on the battery section.

With those checks my guess is a broken or loose wire at the 7 pin or somewhere in the harness. Thor has had that problem before

chunker21 · 07-10-2021, 05:37 PM

Quote:

Originally Posted by EA37TS

With those checks my guess is a broken or loose wire at the 7 pin or somewhere in the harness. Thor has had that problem before

That's what I'm thinking also. I tried to follow the wires and this is what I've come up with. The orange "charge wire??" at the 7 pole plug goes forward and disappears somewhere over the fuel tank, the orange wire coming from the BIM? by the battery box and 20 amp fuze wire goes forward also and is lost in looms somewhere forward of the battery box area. The 20 amp fuze connector by the battery box has 12v passing through it. The 30amp fuze in the main fuze box passes current in spot 7 but not 26.

I think the power source for the 12v trailer battery charge goes from the battery area and BIM, forward to the main fuze box then aft to the 7 pole connector. Somewhere the connector doesn't "connect"????

In the time I've searched this, I could have gone to the store, bought 30' of 12ga wire and appropriate connectors and fuzes, installed it and been drinking a cold one.

Meanwhile my TPMS came in from RVi and a repair claw for the RVi3 so I'm going to work something else.

Chateau_Nomad · 07-10-2021, 05:39 PM

Just for giggles, start the engine and turn on headlights... then test. Shouldn't make any difference, but if you don't know who wired it...

My vote (if fuses are good) is a loose/poorly crimped wire at the connector. Splice into the wire before the connector and check there.

My connector has small Philips screws holding the wires onto a contact plate... if yours is like that, check those screws.

chunker21 · 07-10-2021, 05:43 PM

Quote:

Originally Posted by Chateau_Nomad

Just for giggles, start the engine and turn on headlights... then test. Shouldn't make any difference, but if you don't know who wired it...

My vote (if fuses are good) is a loose/poorly crimped wire at the connector. Splice into the wire before the connector and check there.

I sort of did that. Took the sharp point of the multimeter and poked through the insulation on the orange wire right by the 7 pole connector and scraped the negative lead to the frame ground. Nothing!!

Chateau_Nomad · 07-10-2021, 05:48 PM

Quote:

Originally Posted by chunker21

I sort of did that. Took the sharp point of the multimeter and poked through the insulation on the orange wire right by the 7 pole connector and scraped the negative lead to the frame ground. Nothing!!

That's exactly what I was thinking...
Well, nix that... it's somewhere else! Isn't troubleshooting a needle in haystack fun??

chunker21 · 07-10-2021, 06:56 PM

Quote:

Originally Posted by Chateau_Nomad

That's exactly what I was thinking...
Well, nix that... it's somewhere else! Isn't troubleshooting a needle in haystack fun??

A thrill a minute

chunker21 · 07-10-2021, 09:51 PM

Quote:

Originally Posted by EA37TS

With those checks my guess is a broken or loose wire at the 7 pin or somewhere in the harness. Thor has had that problem before

I could spend countless hours trying to chase an unknown break or problem so my plan is to run a new line. What are your thoughts on running a 12ga line with 20amp breaker off one of the chassis batteries positive pole back to the 7 pole plug and splice it into the appropriate pole on the plug? I have an RVI charging set already to put in the toad.

chunker21 · 07-11-2021, 12:32 AM

It seems that newer Fords that have the trailer tow wiring have to be connected to a trailer and the trailer detected in order to get the 12v charge line to provide the 12v. I did a google search of Ford trailer charge line and brought up several articles, primarily from Ford truck forums, that addressed the issue. You have to connect to the trailer and engage the brakes to activate the 12v charge line. Either press the brakes or activate trailer braking on the dash. There was also explained a way to bypass by installing a jumper wire on the trailer tow module which would make 12v constant.

My toad isn't finished with the lights wiring yet so I can't connect yet to check that. Next couple days will finish it and hopefully all will be well.

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