providing power to Scamp electric brakes

[MJo]

I bought the 13 ft. Scamp with electric brakes but Volvo will not change the 4 pin electric harness to a 7 pin so I can use the electric brakes. Scamp service says, “It’s a fairly straightforward” process all I need in addition to the 4 pin is a ground and 12volt for power. Has anyone had this problem? I have the part to use, it provides for hooking up the 4 pin and the black, white, blue and yellow wires to use. white = ground, I think Scamp uses the black for the brakes, but I can check the diagram from Scamp. Also, the owner’s manual from Scamp shows the layout of the Scamp 7 pin connector. How would anyone deal with this? Is this something I could do without short circuiting something on my car? thanks to any kind soul willing to offer sage advice.
actually Scamp said, “ It iis fairly straightforward to wire up. You will need the 12v and ground the blue and yellow wires can be ignored as the controller is in your trailer and not in the car.”

[MJo]

I am thinking I could use the 2nd cigarette lighter outlet in the back seat and plug a long cord into it for 12 volt? would that work?

12V 15A Heavy Duty Male to Male Cigarette Plug Cigarette Lighter Adapter Charger Cord With LED Lights And Fuse Protection On Both Plugs available from Amazon

[gordon2]

Sounds like Scamp installed the Autowbrake device.. there is info about the controller on their website.
You need a 4 to 7 pin conversion and then run a 10 gauge wire from the battery positive post to the 7-pin brake power pin with a self-resetting circuit breaker at the battery end. Dont tap in to the lighting circuit or use an outlet for the brake power. If you overload the circuit you end up with no brakes. If you confuse the vehicle's computer by drawing power from the lighting circuit then who knows what mayhem will occur. Also don't use the trailer's battery for the brake power.. if it goes low, brakes fail. Just use a wire from the vehicle battery to the trailer's brakes via the 4 to 7 pin. Maybe you should start looking for a trailer shop who is familiar with the Autowbrake controller, or is willing to study the support info on their website and then do the job.

[MJo]

I’ve gone to an RV store, Major’s, here in Falmouth, MA, I’ve also argued with 2 Volvo service departments. the RV store won’t deal with a Volvo car and the Volvo dealer won’t hook up another brand to their Volvo. I contacted Scamp and You can see their reply, “It’s a fairly straightforward….etc.”. I am concerned about the gauge of the Amazon product, whether it is the right wire, otherwise, it seems like a snazzy way to obtain 12 volt instead of going to the car battery.

[AlanKilian]

Did Scamp install an electric brake controller on the trailer?

I installed a Tekonsha trailer-attached brake controller and hooked it up to our 2004 Volvo V70 with no issues.

But it depends on what you've got on your trailer.

[gordon2]

Originally Posted by MJo

I.. I am concerned about the gauge of the Amazon product, whether it is the right wire, otherwise, it seems like a snazzy way to obtain 12 volt instead of going to the car battery.

If by "snazzy" you mean inherently dangerous, then I agree.

With increasingly complicated vehicle electrical systems, fewer and fewer shops are willing to do anything that might void the warranty or cause a problem. Toyota is bad enough.. Volvo is apparently worse.

What I have suggested (wire from the battery to the controller on the trailer) does not have any impact on the Volvo's electrical system and is therefore the best and safest way to do it... expect for the better option of using a tow vehicle that is actually wired and equipped for a trailer with brakes.

If you must use a Volvo as a tow vehicle, then you need to work harder to find a good shop to make the needed modifications.. or DIY. But if you DIY then DIR (Do It Right).

[MJo]

Originally Posted by AlanKilian

Did Scamp install an electric brake controller on the trailer?

I installed a Tekonsha trailer-attached brake controller and hooked it up to our 2004 Volvo V70 with no issues.

But it depends on what you've got on your trailer.

Yes, Scamp installed the brake controller in the Scamp. I watched the video on the Autowbrake website and they said to connect the power to the brake lights on the tow vehicle. How did you do it on your V70? did you have to convert a 4 pin connector to a 7 pin? that is my problem.

(Scamp supplied a remote to control the brakes for now, I will stay with that instead of putting a controller in the car.)

[MJo]

Originally Posted by gordon2

If by "snazzy" you mean inherently dangerous, then I agree.

With increasingly complicated vehicle electrical systems, fewer and fewer shops are willing to do anything that might void the warranty or cause a problem. Toyota is bad enough.. Volvo is apparently worse.

What I have suggested (wire from the battery to the controller on the trailer) does not have any impact on the Volvo's electrical system and is therefore the best and safest way to do it... expect for the better option of using a tow vehicle that is actually wired and equipped for a trailer with brakes.

If you must use a Volvo as a tow vehicle, then you need to work harder to find a good shop to make the needed modifications.. or DIY. But if you DIY then DIR (Do It Right).

Thanks for your reply. I’ve been looking, since October 2020, for a qualified, Volvo knowledgeable shop to convert the 4 pin to a 7 pin and am to the point of cussing them all out. I’ve gotten responses from ignorant to insulting. So, if I want the electric brakes, at this moment I only have me to find the information to do it. the Autowbrake (manufacturer of my brake controller) video says to use the brake lights on the tow vehicle for the brakes power source.
I will keep looking for detailed instructions that are within my understanding before I disconnect or attach anything. I value my 17 year old Volvo more than having electric brakes, if it comes to that.

[ThomasC]

Originally Posted by MJo

Thanks for your reply. I’ve been looking, since October 2020, for a qualified, Volvo knowledgeable shop to convert the 4 pin to a 7 pin and am to the point of cussing them all out. I’ve gotten responses from ignorant to insulting. So, if I want the electric brakes, at this moment I only have me to find the information to do it. the Autowbrake (manufacturer of my brake controller) video says to use the brake lights on the tow vehicle for the brakes power source.
I will keep looking for detailed instructions that are within my understanding before I disconnect or attach anything. I value my 17 year old Volvo more than having electric brakes, if it comes to that.

I was an imported auto mechanic all of my life. I always worked in dealerships. VW, Porsche and Audi in the 70's then Honda and Volvo in the 80's and finally Mercedes Benz in the 90's until I got burnt out by flatrate and dealerships.

I worked in a lot of different dealers and there were never very many mechanics who could do electrical work. Maybe one or two in a shop if you were lucky and it got worse as time went by. No one wanted to pay decent mechanics and they drifted into other lines of work. So you are running into this shortage.

Anyway I think your idea of that rear lighter or power socket as they are now called is a good idea. Just find out what fuse feeds it and how many amps the fuse is. Just because Amazon says their rig is 15 amps it isn't so unless the car has a 15 amp fuse.

Etrailer has a lot of info if you want to poke around. I suppose this is what I get for waking up at 3:00 AM.

https://www.etrailer.com/Trailer-Bra...leID=200482891

[gordon2]

Originally Posted by MJo

...the Autowbrake (manufacturer of my brake controller) video says to use the brake lights on the tow vehicle for the brakes power source.....

Not the brake lights.. you would use the running lights for constant power instead of only when the brake lights were on. The Autobrake installation page even underlines and bolds that sentence:
Use running lights as direct 12-volt power source.

They also say this:

When using this option, you must have your vehicle lights turned manually to the on position, and not use the automatic light feature. You must also know if you fail to turn the tow vehicle lights on while towing you will also not have functioning trailer brakes.

What they don't say is how to tell if the lighting circuit can handle the additional power requirements or if the intermittent added power draw will cause the vehicle computer to show a fault. So there are many ways that using this method can fail.

As for the cigarette lighter idea.. these plugs are notorious for falling out, which would leave you with no trailer brakes. And you would need to run the wiring from the inside of the Volvo to the 7-pin or trailer on the outside. So you either drill a hole or pinch the wire under a door. If you make a hole, be sure to use a grommet to prevent abrading the wire's insulation and causing a short. If you run it on the door seal, the wire will probably break someday from being pinched repeatedly.

In both of the above scenarios, a blow fuse will leave you with no trailer brakes.

I really don't understand why you are reluctant to do the simplest and safest thing.. and this is the last time I will suggest it:

1. Add a 4 to 7 pin conversion.. see above post.
2. Add a short run of 10 gauge wire from the battery positive post to a self resetting circuit breaker in the engine compartment. The breaker will reset and restore your brake power on it's own if it suffers an overload, giving you time to get stopped and fix the overload.
2. From the breaker, run 10 gauge wire under the vehicle to the 7-pin. Secure the wire and keep it away from the exhaust system.

This way you make no holes in the car, don't pinch the wires, don't need to worry about fuses blowing, a plug falling out or computer faults. Safe, secure and simple to do. It does not alter the Volvo's electrical system at all and it can be removed in minutes when you get ready to trade the Volvo for another tow vehicle. If your new tow vehicle is fully pre-wired at the factory for towing then you avoid all this hassle.

If you like videos, see this one at one minute 30 seconds (1:30):
https://www.etrailer.com/tv-review-a...r-3430001.aspx

Or at 2:20 in this video:
https://www.etrailer.com/tv-Demo-Aut...r-3430001.aspx

[bertherr]

See if this video helps you understand what is needed. Bert

https://www.etrailer.com/Custom-Fit-...rt/C57186.html

[Lynn Eberhardt]

I would modify Gordon's suggestion slightly.
Install a 4 to 7 pin conversion.
Run a 10 gauge wire from the auto battery positive with an inline auto reset circuit breaker and a voltage sensing relay.
Connect that wire to the 12 volt connection on the 7 pin.
Connect the AutowBrake unit to the trailer battery.
Now, the trailer brakes will work, the trailer battery will charge while you're driving, and the car battery will not discharge when you stop and remain connected.

[gordon2]

Lynn, I would modify your modification slightly..

For the charge line, run a separate wire from the battery to the 7-pin. Use a fuse at the battery. Thats they way I wired my rig.

The voltage sensing relay on the charge line is preferred but not required as long as you dont let something like the camper's fridge run down the tug's battery (i.e. disconnect). In fact a charge line is nice to have but it also is not required. I have been without one more than I have had one.

The brake power line should be dedicated to the brakes alone for maximum safety. It is also about the only time you use a self-resetting breaker instead of a fuse. Normally if there is a circuit overload you want the power shut off (fuse blown) until the cause of the overload is corrected. However the need to stop a trailer (maybe going down hill at 65 MPH) however justifies using a resetting breaker even though the overload or short might still exist when the power is restored by the breaker.

Lastly, if you do share the power line and use a relay to disconnect power when the voltage is low, it should only be after the run to the brakes power connection on the 7 pin. If a relay is inline between the tug and the trailer's brakes and the alternator fails the voltage will drop and the relay could shut off power to the trailer brakes. As long as the brakes are wired straight to the battery (with breaker) then even if the voltage drops you will still have most of the normal power to the brakes instead of none at all. The relay can be inside the trailer, between the incoming charge line and the rest of the trailer's electrical system.

[MJo]

all you wonderful people have such great ideas. I’ve just been looking for a way that this 86 year old woman (but mechanically inclined, I was a nurse for 35 years) who has been eating too many Pepperidge Farm cookies lately (especially the macadamia nut with white chocolate) and might get stuck crawling under the XC-70 to run the wires you’re talking about. I’ll think on it. I’m not adverse to doing what you suggest, I just am not to the point of feeling I can do it. I’ll keep reading your suggestions and learning. At this moment, electric brakes aren’t mandatory, just preferable. I’m very appreciative of your efforts to school me.

[gordon2]

There are many DIY types who can wire this up for you.. but how to find one near you I don't know. Maybe a RV club, or ham radio club where the members routinely do low voltage wiring. Maybe even a High School auto shop class. But it seems like there must be a U-Haul or other shop that would do this.. after all, they are not making ANY connection to the Volvo except at the battery post. Add the 4 to 7 pin adapter, plug it into the 4 pin that you already have, connect the brake wire and breaker to the battery.. done.

Skills needed include proper crimping technique and knowledge of the right size ring terminals (color coded to wire gauge) as well as how to check for power and polarity (multi-meter). Also spend an extra dollar for ring terminals with heat shrink to make a water tight seal on the wire. Dont use the veh or trailer frame for the electrical ground (negative).. use wiring instead. And disconnect the battery neg side while wiring things up and keep the trailer unpowered also.

[MJo]

seems like it, but so far no luck. I may just make a list of the parts you mention, I already have the 4-7 connecter so the 4 is done, just need the ground and power to the brake controller. Maybe on a nice day….. I’m still needing to hang the license also. I wish the video showed attaching the wire to the battery post and adding the fuse, I can visualize doing the rest of it, I think. I won’t go through all the calls I’ve made, U-Haul and the rest, I would have used them. I just haven’t found anyone who would. either it’s that I have a Volvo, or that I have a brake controller, so far I’ve only found the skeptics. I’ll keep soaking up the advice that is coming my way and it may be enough. I appreciate the warnings, I don’t want to damage my great old Volvo. We’ve been through a lot together.

[AlanKilian]

Originally Posted by MJo

seems like it, but so far no luck.

I just completed this EXACT think on my 2004 Volvo V70 wagon.

Can you post a photo of the existing wiring you have for your 4-pin connector?

I'd be happy to post what I did to get the 4-to-7 harness wired up.

I used this one in the car:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I installed a Tekonsha RF brake controller on the Scamp, but it shouldn't make any difference what controller you have installed.

[gordon2]

Originally Posted by AlanKilian

..
I installed a Tekonsha RF brake controller on the Scamp, but it shouldn't make any difference what controller you have installed.

Actually, it makes a big difference what controller you have installed.. however your Tekonsha RF brake controller is similar to the Autobrake unit and wiring will be about the same. So your example should be very helpful. Too bad you can't stop by and hook it up for the OP

These "wireless" controllers are not nearly as common as hard wired ones, and installing a hard wired one is very different.

[MJo]

the controller was wired into the RV and I have a remote to work the controller to adjust the brakes to work with the car’s brakes, not too soon or too late, so the RV doesn’t top the car and the car doesn’t stop the RV too soon. The problem is getting power to the controller. 12 volts. I ran my idea by Scamp and they were concerned that using the source in the back seat would not be enough power. they prefer connecting to the power post on the car’s battery and adding a fuse.

[sunnyone]

We had a trailer supply and service business in our metro area wire our Tacoma with the 7 pin connector before we picked up our new Scamp with the Autow brakes. Is there a trailer service business near you that could do it?