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RVing message boards => Towing and towables => Topic started by: Bozopolis on March 27, 2017, 06:07:54 PM

Title: tow dolly
Post by: Bozopolis on March 27, 2017, 06:07:54 PM
We just purchased a previously owned (used for my fellow Oklahomans) Class C Fleetwood Tioga. When we take a long trip we'd like to take one of our cars which are both front wheel drive Kias and know they can't be towed with all 4 wheels down. I found a really nice, almost new Master Tow Dolly locally. Came with a spare set of straps and a spare tire. I noticed that it isn't equipped with safety chains for the towed vehicle. They have them as parts on the Master Tow website but in the picture it shows the chains attached on the pivoting base but my dolly doesn't look like it has any place to attach the chains. Now I'm wondering if I've screwed up. Does anyone have one of these dollys? Do you think the chains are necessary (not the ones that attach the trailer to the hitch but the ones that secure the actual towed vehicle to the tow dolly). The lady I bought it from said they never had them. The manual says to attach them "if equipped". I guess I can wait to see if they come with instructions but I was hoping maybe someone on here would know.

Title: Re: tow dolly
Post by: Bozopolis on March 28, 2017, 03:04:00 AM
I also just found out from the seller that the dolly does indeed have electric brakes. Can anyone tell me what is necessary to make them work and if my RV is already wired is there anyway to test them to find out if they indeed work?

Thank you
Title: Re: tow dolly
Post by: Gary RV_Wizard on March 28, 2017, 09:15:40 AM
To operate electric brakes the tow vehicle must have an electric brake controller.  If the coach already has a 7-pin trailer connector, it has a pin assigned to a brake controller but it may not be wired at all or may have a wire that dead-ends up front somewhere. Odds are there is no brake controller already installed, though, unless a former owner had a need for one as well.  It would be quite obvious up in the dash area if there is one.

This article may help:
Title: Re: tow dolly
Post by: Bozopolis on March 31, 2017, 12:36:31 PM
It does have the 7-pin trailer connector. I'm sure there's no brake controller. I've read different things and I called local places to ask for estimates. The hitch place quoted me $400-500 based on my motorhome's length of 31 feet. One RV repair place just referred me to the hitch place. The other RV place wants me to bring in the dolly and RV to check it out.

If I bought a controller and the correct plug for the 2005 Ford E-450 and plugged it in is there a way to see if I'd need to do other wiring with the 7-pin connector? I want it done right and to work right but I also don't want to spend tons of money on labor if all they're going to do is charge me twice the cost of the controller and an hour's labor for plugging it in. Is there a way with some kind of tester I could tell if the 7-pin connector is already factory wired or does any manufacturer actually do this?

Title: Re: tow dolly
Post by: RedandSilver on March 31, 2017, 04:32:03 PM
If you looked at the link Gary supplied they show the trailer brake wire as BLUE.

First thing I would do is look to see if there are really 7 wires to your 7 pin connector.
It's possible that there could only be 6 wires as One wire might be for a reverse light.
Probably not too many trailers have reverse lights so not all plugs are wired for that.
On my SUV they are all wired and my trailer DOES have reverse lights and they work - but on my MH they don't,
so I assume that wire may not be hooked up - that's why I mention this....

IF there are 6 or 7 wires, then see if you can trace those wires all the way up front.
One wire from the controller will have to run back to the 7 pin plug.

Since your going to need a brake controller - go ahead and buy one.  IF you have someone do the wiring
because you can't find them or don't want to do the work - you can tell them you already have one so they can't overcharge you for one.

You might call and tell them what your going to do and they can probably recommend a Brake Controller
that will work for you.  I bought my controller there.  I have the P3 and like it real well because it shows the voltage going
to the brakes.  The harder you brake the more voltage sent to the electric brakes on my trailer.  JMO.

Title: Re: tow dolly
Post by: RedandSilver on March 31, 2017, 06:48:57 PM
In case you try what I suggested:

Just wanted to make you aware that the Blue wire comes from the Brake Controller harness and not the 7 pin plug.

I Don't know why they can't wire them up so that all the colors match but in most cases they DON'T.

With a Fluke meter I think you could have someone step on the brake pedal while you check the 7 pin connector
for voltage at different pins and figure out what wire goes where.  Repeat for each turn signal etc.

If someone else is going to do the work then forget what I said.  However you did indicate that you didn't want to spend a lot, right?
Title: Re: tow dolly
Post by: rockman on March 31, 2017, 07:56:43 PM
I needed to replace the safety chains for our dolly and got a set from NAPA auto parts, not very expensive, and good insurance just in case.