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noserider · 05-05-2015, 08:06 PM

Hi Folks

I just installed my Blue Ox base plate on my Jeep Liberty and now on to the wire harness for lights. I purchased a Tow Daddy harness that plugs into the tail light assembly and has a 4 wire flat that you bring to the base plate. My coach has a round blade connector. It has 6 blades and in the center the previous owner ran a fused hot from the coach battery to use as a toad charge line. I have attached a couple pics. What do I need as far as adapters for this setup? BTW not counting the red wire that I think is attached to the center of the coach receptacle...there is only 5 wires but the plug has 6 blades. I also removed the 4 mounting screws on the round plug and also removed all the screws on the back of the plug to see where the red battery hot was attached but I could not get the plug apart. I did not want to break it but tried pushing the wires forward but the plug did not want to come out of the housing. Does it twist out and unlock?

WILDEBILL308 · 05-05-2015, 08:20 PM

Look hear.
Trailer Wiring & Electrical - Installation Guide | Hitch Info
Bill

**Lt Dan** · 05-05-2015, 08:24 PM

There is an adapter that goes from the seven wire round coach plug direct to the four wire flat. It is available at most auto part stores that have trailer wiring. If the PO wired it to standard, the hot wire should be in the upper right, two o'clock position viewed from the rear. That's easy to check with a test light.

Once you have removed the screws, the insides of the plug should just push out.

noserider · 05-05-2015, 08:43 PM

Quote:

Originally Posted by WILDEBILL308

Look hear.
Trailer Wiring & Electrical - Installation Guide | Hitch Info
Bill

Thanks Bill. I actually found that link and read it before posting. Still have some unanswered questions. The wires going to my receptacle are all white except the red that the previous owner ran for the toad charger. Also the Towdaddy 4 wire flat is 3 females and a male. The adapters I have seen online from 4 wire to round 6 or 7 seem to be set up to accept a flat with 3 males and a female.

noserider · 05-05-2015, 10:23 PM

Quote:

Originally Posted by Lt Dan

There is an adapter that goes from the seven wire round coach plug direct to the four wire flat. It is available at most auto part stores that have trailer wiring. If the PO wired it to standard, the hot wire should be in the upper right, two o'clock position viewed from the rear. That's easy to check with a test light.

Once you have removed the screws, the insides of the plug should just push out.

I guess it was just stuck. Did you notice the 3 female and one male end on the flat plug? Most pictures of adapters show the adapter having the same configuration as the the 4 wire flat I have. I would need one with 3 males and a female. I was hoping to also use my umbilical cord that came with the coach that mates up with my 6 round blade coach connector.

ShapeShifter · 05-06-2015, 04:30 PM

Quote:

Originally Posted by noserider

I guess it was just stuck. Did you notice the 3 female and one male end on the flat plug? Most pictures of adapters show the adapter having the same configuration as the the 4 wire flat I have. I would need one with 3 males and a female.

No, the adapter polarity is correct, you have the wrong umbilical cord. For a flat-four connector:

The tow vehicle (supplying the lighting power) has one male prong (ground) and three female sockets (supplying power to the lights.)
The towed vehicle (receiving the lighting power) has one female socket (ground) and three male prongs (receiving power for the lights.)

The polarity is important: the female sockets are recessed and resistant to accidental shorts. That's why the power supply to the lights is always on female sockets. If you had three male pins on the tow vehicle side, the power for the lights would be on the exposed pins, and it would be VERY easy to have an accidental short by just having the connector brush against some metal on the tow vehicle.

The flat-four connector you are picturing is the end that is supposed to plug into the toad, not the motorhome. That cable is backwards and needs to be swapped end-for-end.

noserider · 05-06-2015, 05:55 PM

Thanks for the explanation. Makes perfect sense. Wish someone would have explained that to the maker of the Towdaddy harness I purchased. Just does not seem right I have to cut off a perfectly good connector to swap for the correct one. They must have made an extension that had 3 males and 1 female on each end to connect to the Tow vehicle and the tow daddy harness. Maybe this gave them a reason so sell and extra set of connectors to use with their harness.

dadej · 05-07-2015, 06:01 AM

I think you have to consider if the tow vehicle has a seperate turn bulb or is it the same bulb as the brake light. The same goes for the toad. If they are the same no convertor is needed other than a seven to four wire. If they are not the same go to the parts store and get a hoppy convertor to blend the two together. Go to the hoppy web site for help.

Dan

ShapeShifter · 05-07-2015, 08:26 AM

Quote:

Originally Posted by noserider

Wish someone would have explained that to the maker of the Towdaddy harness I purchased.

Do you have a link to the harness or a model number for it? I wonder if this was designed as a tow vehicle harness so you can add the wiring to pull a trailer? That would explain the connector they chose, but wouldn't explain why the wire leading to the flat-four connector is so long.

You say it connects to the tail lights: does it include some sort of diode isolation (often a small box where the left and right sides come together)? Or is it just straight wires from the tail light sockets to the flat-four connector?

I'm just trying to make sure you have the right harness, because either you got the wrong type, or they made it with the wrong type of connector. There are harnesses to add wiring to pull a trailer (which I'm afraid you might have) and harnesses to add wiring to make it a toad (which is what you need.)

As an example, this is the wiring harness I recently used for my toad:

Click to enlarge

At the bottom of the picture, you can see a plug and a socket for the driver side: unplug the connector to the tail light, plug it into the socket, and plug the plug into the tail light. On the left center is the passenger side plug/socket. next to it is the black box with white printing that holds the necessary isolation diodes. Then, at the top is the wiring that runs up front with the flat-four connector. Note that it has the correct polarity with the three male prongs.

Having the wrong connector is one clue. If it also does not have something like that black box with the isolation diodes, then it very well may not be the right harness for a toad. Without the diodes, when the motorhome tries to turn on any light, it will back-feed the wiring to the car's control systems, and many modern vehicles will not cope with this well: it can cause damage. Before you cut off that connector and replace it with a different polarity, I just want to make sure you have the right harness.

ShapeShifter · 05-07-2015, 08:33 AM

Quote:

Originally Posted by dadej

I think you have to consider if the tow vehicle has a seperate turn bulb or is it the same bulb as the brake light. The same goes for the toad.

That is a valid concern if you are doing all of the wiring from scratch. However, the coach already has a standard 7 pole trailer connector, which should already be set up for combined brake/turn lights. If the toad also has combined brake/turn lights, you're all set. If the toad has separate brake/turn lights, it is not necessary to use an adapter to break them apart, just use the set of bulbs that are used for brake lights. You could also use the lights that are used for turn signals as long as they are red; do not hook the combined turn/brake signal to a yellow turn signal bulb.

The real issue, and the only time you really need a converter, is if the tow vehicle has separate brake/turn lights, AND the toad has combined lights, AND there is not already a standard trailer connector from the factory. The OP's trailer connector looks like it came from the factory, and I'm sure it's a safe assumption that any necessary converter is already in place from the factory.

noserider · 05-07-2015, 09:28 AM

The wire harness is a Towdaddy. It was built specifically to use as a plug and go toad to rv wire harness. It has all the diodes and other stuff built into a small box to do everything you guys mentioned. My toad does have independent blinker and brake lights. This harness setup was designed to work with that feature also. I purchased two 4 flat wire connectors that had 3 male and 1 female and butt spliced them together. I plugged one end into the Towdaady harness and the other end into my RV using a 7 to 4 flat adapter. Everything seems to be working correctly.

ShapeShifter · 05-07-2015, 10:00 AM

Quote:

Originally Posted by noserider

The wire harness is a Towdaddy.

Which model is it? It looks like many models have the proper 4 pin gender, a few have blunt cut wires, but a couple have the wrong 4 pin gender. How curious!

noserider · 05-07-2015, 12:52 PM

Quote:

Originally Posted by ShapeShifter

Which model is it? It looks like many models have the proper 4 pin gender, a few have blunt cut wires, but a couple have the wrong 4 pin gender. How curious!

My box says Tow Daddy Plug-N-Tow part #1003. It is specific for the Jeep Liberty years 2002-07. The harness plugs directly into the tail light assembly. They were bought by Hopkins but Hopkins has discontinued the model and has their own design that I think does the same thing. Not sure if they were just trying to eliminate the competition or decided the product was inferior.

ShapeShifter · 05-07-2015, 03:08 PM

Quote:

Originally Posted by noserider

My box says Tow Daddy Plug-N-Tow part #1003.

Very interesting. Look at this listing, and it very clearly shows the correct gender of plug, which is the opposite of what you have. It looks like they manufactured yours with the wrong plug?

Quote:

Not sure if they were just trying to eliminate the competition or decided the product was inferior.

Might be they had their own version of the product, or it might be the "not invented here" mentality. Or, given the apparent manufacturing error in yours, they may have discontinued it in favor of their own product with better quality control?