providing power to Scamp electric brakes

[gordon2]

Originally Posted by MJo

... 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.

Gee.. why didnt I think of that? Oh wait.. I did.. and I suggested it THREE times. (except for using a 12 VDC breaker in place of a fuse). You have the info you need now from multiple sources. Get er done.

[MJo]

This is my first time dealing with the car’s wiring. I have some experience with cars, I had a 62 Chevrolet, great car !!! I changed the oil, spark plugs, lamps, but haven’t dealt with the battery except to put one in when that one was stolen. So I need a wire, what gauge? and a fuse or “VDC 12 volt breaker” and hook that up to the positive post on the car’s battery, (under the hood, I know) and have the wire long enough so it will reach, under the car, away from the muffler that gets hot, to the part I have which has a 4 pin connector and the black wire for power to the controller and a white wire (ground) to put on the frame. and the blue wire goes somewhere too. once they are all connected, if they service the same parts that the matching colors on the Scamp plug service, I’m ok. BUT if they don’t, then I’ll have to figure it out, I guess by just seeing what works after it’s put together. I got a gadget that tests the 7 pin plugs. I would also have a “buddy wire” to accompany the power wire and support it while it passes under and over projections under the car. What am I saying that is wrong? this is what I think you’ve been saying. or is it?

[Bing M.]

Run the power directly from the positive battery post to the plug in the rear of the car. DO NOT use a fuse in this line! Use a auto-resetting circuit breaker. If you use a fuse and it blows you are out of brakes. With a circuit breaker at least it will reset and give you a second of brakes when it resets, better than none at all. Place the breaker close to the battery, this way it protects the entire wire run from a short.
On my better 2/3's 2001 V70 Volvo the battery is under the floor of the rear compartment. Made running wiring a easy-peasy job. Good luck and enjoy your camping adventures!

[John in Santa Cruz]

For that battery power wire, I would use AWG 10 gauge wiring and a 40 amp auto-breaker. I like adding a relay, rated for at least 50-60 amps, wired like...

relay pin 30 to the output of the 40 amp breaker
relay pin 87 to the AWG 10 wire to the 7 blade 'power' pin 4 (usually red on the vehicle side)
relay pin 85 to ground, can use a relatively thin wire like AWG 18
relay pin 86 to a switched power source on the vehicle under the hood, this is often known as 'circuit 15' on european cars, its on when the ignition is on, and off when its not, this also can use a relatively thin wire like AWG 18.

the pin 86 to 85 is the 'coil' circuit of the relay, that turns on the power circuit of 30 to 87. these relay pin numbers are the european numbers, used on Bosch "VW" relays and similar.

this relays function is to shut off vehicle power to the trailer when the vehicle is off, so the trailer doesn't run down your vehicle battery when you stop. when you are driving, this will charge your trailers battery as well as supply power to the RF brake controller.

also be sure the 7 blade connector 'ground' pin 1 is wired to vehicle chassis ground with at least AWG 10 wiring.

[MJo]

Originally Posted by Bing M.

Run the power directly from the positive battery post to the plug in the rear of the car. DO NOT use a fuse in this line! Use a auto-resetting circuit breaker. If you use a fuse and it blows you are out of brakes. With a circuit breaker at least it will reset and give you a second of brakes when it resets, better than none at all. Place the breaker close to the battery, this way it protects the entire wire run from a short.
On my better 2/3's 2001 V70 Volvo the battery is under the floor of the rear compartment. Made running wiring a easy-peasy job. Good luck and enjoy your camping adventures!

The battery of my 2004 XC-70 is under the hood to the right of the engine so I have to run the battery the length of the car. Where do I buy a auto-resetting circuit breaker and does it have to be the same gauge as the wire? Or does it come in sizes? thanks for replying.

[MJo]

Originally Posted by John in Santa Cruz

For that battery power wire, I would use AWG 10 gauge wiring and a 40 amp auto-breaker. I like adding a relay, rated for at least 50-60 amps, wired like...

relay pin 30 to the output of the 40 amp breaker
relay pin 87 to the AWG 10 wire to the 7 blade 'power' pin 4 (usually red on the vehicle side)
relay pin 85 to ground, can use a relatively thin wire like AWG 18
relay pin 86 to a switched power source on the vehicle under the hood, this is often known as 'circuit 15' on european cars, its on when the ignition is on, and off when its not, this also can use a relatively thin wire like AWG 18.

the pin 86 to 85 is the 'coil' circuit of the relay, that turns on the power circuit of 30 to 87. these relay pin numbers are the european numbers, used on Bosch "VW" relays and similar.

this relays function is to shut off vehicle power to the trailer when the vehicle is off, so the trailer doesn't run down your vehicle battery when you stop. when you are driving, this will charge your trailers battery as well as supply power to the RF brake controller.

also be sure the 7 blade connector 'ground' pin 1 is wired to vehicle chassis ground with at least AWG 10 wiring.

Your answer is intriguing. I don't think I have pins 86, 85 and power circuits 30 and 87 but anyway, if I had the parts you are mentioning, it would be fun to hook everything up and it sounds like doing so would prevent problems, I just don't think I have the resources. but, I do like a challenge. But thank you for taking the time to add a suggestion to my query. Take care.

[gordon2]

Originally Posted by MJo

The battery of my 2004 XC-70 is under the hood to the right of the engine so I have to run the battery the length of the car. Where do I buy a auto-resetting circuit breaker and does it have to be the same gauge as the wire? Or does it come in sizes? thanks for replying.

Thomas has already pointed you to e-trailer.. they will have everything you need. But your questions still have me convienced that you need to find a shop (U=Haul, etc) to wire your 4 to 7 pin adapter and brake power from the Volvo's battery (and an optional charge line if you want one).

Originally Posted by ThomasC

...

Etrailer has a lot of info if you want to poke around. ...
https://www.etrailer.com/Trailer-Bra...leID=200482891

[MJo]

Thanks for getting back to me. Yes, I've been to ETrailer and got the part that takes the 4 pin to the 7 pin with the additional wires. And they have videos, etc. Thanks for your explanations, being an old nurse, I am very cautious with my car as I always was with my patients. As far as I know, I never lost one (a patient, I mean) and I won't lose my old Volvo I've had for 17 years and 260,000 miles. Thanks again, MJo

[MJo]

Originally Posted by gordon2

Gee.. why didnt I think of that? Oh wait.. I did.. and I suggested it THREE times. (except for using a 12 VDC breaker in place of a fuse). You have the info you need now from multiple sources. Get er done.

Yes, I think so, I have lots of suggestions and out of that, I think I have the 1 or 2 which I need to 'hook er up' and 'take er on.' the excess gave me lots of reassurance that I understood. thanks.

[John in Santa Cruz]

Originally Posted by MJo

Your answer is intriguing. I don't think I have pins 86, 85 and power circuits 30 and 87 but anyway, if I had the parts you are mentioning, it would be fun to hook everything up and it sounds like doing so would prevent problems, I just don't think I have the resources. but, I do like a challenge. But thank you for taking the time to add a suggestion to my query. Take care.

those are the pin numbers on a standard Bosch style automotive relay.


re: the auto-resetting circuit breaker,
https://www.amazon.com/Bussmann-CBC-.../dp/B001PTBVL2

this should be quite close to the battery (or to the 'positive terminal' your car likely has somewhere under the hood which is tied directly to the battery (+) and has lots of red wires coming off it)

you would crimp ring terminals onto the ends of the wires, sized for your wire gauge and the 10-32 studs terminals (eg, a 1/4" hole in the ring terminal would fit nicely on the 3/16" stud, and a yellow crimp connector is sized for AWG 10-12 wire). I like to use the marine crimps that have heat shrunk insulation, you hit them with a hot air gun after crimping, and they seal around the wires.

yeah, I have to second the motion, you need to find someone familiar with vehicle and trailer wiring to do this job properly, its quite simple for someone with that experience. and yes, the wire would run the length of the car, it could be run through the firewall (there's nearly always a rubber plug that has nipples you can run extra wires through), under the edge of the carpet along the door sills, then through the trunk, and back out to the 7 blade, or it could be run entirely underneath the car, tucking it up out of hte way and secured snuggly so it can't get anywhere near any moving parts or the exhaust system.

[AlanKilian]

Originally Posted by MJo

The battery of my 2004 XC-70 is under the hood to the right of the engine so I have to run the battery the length of the car.

Are you sure it's in the front?

My 2004 V70 battery is in the rear as is the 2004 XC-70 Cross Country.

How to replace the battery in Volvo S60, V70, XC70, S80, XC90

[John in Santa Cruz]

Originally Posted by AlanKilian

Are you sure it's in the front?

My 2004 V70 battery is in the rear as is the 2004 XC-70 Cross Country.

How to replace the battery in Volvo S60, V70, XC70, S80, XC90

on the positive battery terminal, where does that 2nd thickest red wire go, the one thats in the split loom? on most/many vehicles that would go to what I referred to as the 'positive terminal' which is a positive bus bar that lots of OTHER + circuits come from, and would be a very good place to tap 40-50A trailer power if its in the back. if that wire runs all the way to the engine compartment, then not so much. the *thickest* red wire undoubtably runs directly to the starter solenoid, and then on to the alternator.

if you DO attach this AWG10 wire directly to the battery terminal, pay attention to how you route it such that the battery terminal can be removed from the battery (to change said battery) without having to separately remove your extra wire first.



edit: ooooh, i still have the parts catalog for all volvos up to 2005 (I owned a series of late 80s, early 90s volvos).... hmmm, hard to tell from parts but it looks like that wire might just go directly to the main fuse box under the hood, oh well. sadly, I only have wiring diagrams for 240s and 940/960s (which were the models I owned)


my last volvo, a 1992 740 Turbo wagon, over 260,000 miles when I sold it still running great

[AlanKilian]

Originally Posted by John in Santa Cruz

on the positive battery terminal, where does that 2nd thickest red wire go, the one thats in the split loom? on most/many vehicles that would go to what I referred to as the 'positive terminal' which is a positive bus bar that lots of OTHER + circuits come from, and would be a very good place to tap 40-50A trailer power if its in the back.

Right on John!

I just pulled my battery cover off and indeed, that's just what is at the end of the smaller of the two red cables.

Thanks for letting me know. (I already added a ring-terminal to the positive post for my brakes, and we're getting a new car in a month, so I probably won't update my wiring.)

[MJo]

Oh !!!! I HATE to be wrong about something so basic as where the battery is, in a car I’ve had for 17 years!!!! But, whoever said it’s in the back, next to the spare tire, was correct. I went out and looked. that makes it so much easier to access power to actuate the controller in the Scamp so it can work the brakes. so much easier. I think I won’t have a problem now. Just have to get the circuit breaker and connecters and wire. One of my former husbands was an inventor, had a machine shop, made the laminator Polaroid used to test the seals in the film so it didn’t separate too hard or too easily, had lost a lot of $$ at one point when the film tore instead of separating from the paper. I did on the road sales for our coolant filtration systems but I also worked in the shop and I have the crimpers and things for the wire. I’ll read everything again, to be sure I have what I need and how to do it. Scamp service is a good resource also. thanks guys, you were right.

[MJo]

Originally Posted by Bing M.

Run the power directly from the positive battery post to the plug in the rear of the car. DO NOT use a fuse in this line! Use a auto-resetting circuit breaker. If you use a fuse and it blows you are out of brakes. With a circuit breaker at least it will reset and give you a second of brakes when it resets, better than none at all. Place the breaker close to the battery, this way it protects the entire wire run from a short.
On my better 2/3's 2001 V70 Volvo the battery is under the floor of the rear compartment. Made running wiring a easy-peasy job. Good luck and enjoy your camping adventures!

looks like you and I are talking about the same car, Volvo. so, what size wire and what amp circuit breaker? can you walk me through it? battery > circuit breaker > wire > 7 pin connecter. correct? so I need circuit breaker of the correct amperage and correct wire and connecters to attach to the wire to attach it to the parts. You were correct, battery in the back next to the spare tire.

[AlanKilian]

Originally Posted by MJo

I think I won’t have a problem now.

I live in Cambridge, so if you're close, and are comfortable, I'd be happy to help you do the wiring. Everyone in our house if fully vaccinated, but I'd be happy to wear a mask if you like.

Either at my house, your house, or in the parking lot of The Artisan's Asylum in Somerville. I'm a member there and I can use all the tools/wire/connectors etc.

Send me a message if you think this is the way to go.

[MJo]

That’s very generous of you.. I’m in East Falmouth, on the Cape, so maybe I’ll get the parts if you can tell me what I need, and lay it out and then go from there. It’s a long drive for me up to Cambridge. (once you live on the Cape, going across the bridge seems like going to a foreign country!) I used to live in Brookline when I was a graduate student at BU and later taught at B.C. I’m sure everything has changed a lot. I went to Joyce Chen’s Chinese Restaurant back then. In the mid-60’s. Cambridge used to be a ‘challenge’ to drive in, I’m sure it’s much worse now.
I really appreciate your offer to help. I’ve been searching for a qualified shop to do it and I get the same answers, “Volvo, no!”. and “RV wiring for a controller? No!”. Even tho I tell them, I just need 12 volt to the cable that goes to the RV from the car. Same story over and over. Thank you so much. I’ll take you up on the offer if the offer still holds. Whew !!!! what a relief !!!! thank you so much.

[MJo]

there are in-line circuit breakers on Amazon of various voltages by Bussman? and others

[AlanKilian]

Originally Posted by MJo

I’m in East Falmouth, on the Cape

If only we hadn't sold our place in Dennis two years ago, it would have worked.

I think this group can get you the information you need to have almost any local automotive garage do the wiring for you.

You say that you have a 4-pin trailer wiring harness currently installed right?
If so, that would be awesome since you only need to connect three more wires.

Ground (a second ground)
+12 Volts
Brake signal.

I have a thing installed that takes all these signals and has the four-pin coming out of it, so it was VERY simple for me to get the seven-pin working.

Let us know and we'll get you there.

[MJo]

I also bought a part to attach to my 4 pin on the car. The part accepts the 4 pin and has a cable with 5 wires, I’d have to go get it but if I remember correctly, it has a black wire (power to the controller), yellow wire (accessory), white wire, (ground) and blue wire (controller). I’ll look for the email I got from Scamp, the service manager said what I need. I have the picture of the Scamp’s 7 wire connector, just have to make sure that on the 7 wire connector I have, the colors go the same places. I got a gadget to plug the connector into that will tell me which leads are working. The part I bought may be similar to what you have to adapt the 4 pin to the 7 pin.