Trailer brakes - The 1947 - Present Chevrolet & GMC Truck Message Board Network

nitor · 11-24-2005, 09:50 AM

I don't know if this is the place to post this, but I am pulling this with my 70 GMC, so....

I borrowed a car trailer yesterday. I needed to hook up a plug on the trailer, the plug that was on it didn't include the trailer brakes. He hadn't ever used the brakes on the trailer. I should say he hadn't had the trailer that long. Anyway, their are two wires for the brakes on the trailer (brakes on only one axle), a black one and a white one. I'm not sure what wire goes to what, and I don't want to hook something up wrong. I would guess the white is ground and the black is hot. Any thoughts?

jku72 · 11-24-2005, 11:22 AM

It could be either. My experience says that the brake wire is a red one, with the ground black, in your case, I would do a temporary hook up one way, try the brake, if it works, try it the other way, and see which way works best. Dont rely on grounding through the hitch.
This is my non professional opinion.

LUV2XCLR8 · 11-24-2005, 11:29 AM

Without trial and error there is no way to be sure

nitor · 11-24-2005, 11:31 AM

Thanks for the reply guys.

Happy Thanksgiving.

Longhorn Man · 11-24-2005, 12:16 PM

A couple fuses in your power and ground wire for testing reasons wouldn't be a bad idea.

jimfulco · 11-24-2005, 10:08 PM

Do you have a brake controller on your truck? If not, you might not want to hook the brakes up, because the trailer brakes might lock up prematurely, causing the trailer to try to pass you.

**Boog** · 11-24-2005, 10:38 PM

Nitor you do have a brake controller in your truck don't you?
The trailer brakes will ground through the connector not the frame. Not a guarantee but some trailers use the black for the positive and white for the negative. Not all brake wires are the same color. If you hook it up wrong you could destroy your brake controller. How about with the trailer removed from your truck place a battery near the front of trailer and run a couple of jumper wires to those brake wires using an inline fuse on each wire. By touching the two wires to the battery posts it should activate the brakes. You should hear a solenoid type of click when activated. Reverse the wires at the battery and touch them again. It may not make any difference which wire is hot as the brakes are magnetically charged when the power is applied.
Are there any RV dealers in your area? Someone there could be of a lot of help as they hook up these all the time.

CG · 11-24-2005, 10:38 PM

i agree with jim on this one. i purchased a trailer with brakes on both axels. first time i used it when you turned on the blinker the trailer brakes went on and off with the signal. i decided to rewire the entire trailer. i did a google search and there are a ton of sites with diagrams for wiring trailers. i ended up going to an rv supply store to pick up some lights and stuff and those guys were a wealth of knowledge helping me rewire my trailer.

Longhorn Man · 11-24-2005, 10:41 PM

I automaticly assumed we were talking surge brakes.
If there is no contropller...then leave them alone and disconnected

11-24-2005, 09:50 AM	#1
nitor Too many projects Join Date: Aug 2002 Location: Morrow, OH Posts: 344	Trailer brakes I don't know if this is the place to post this, but I am pulling this with my 70 GMC, so.... I borrowed a car trailer yesterday. I needed to hook up a plug on the trailer, the plug that was on it didn't include the trailer brakes. He hadn't ever used the brakes on the trailer. I should say he hadn't had the trailer that long. Anyway, their are two wires for the brakes on the trailer (brakes on only one axle), a black one and a white one. I'm not sure what wire goes to what, and I don't want to hook something up wrong. I would guess the white is ground and the black is hot. Any thoughts? __________________ Jim '55 Chevrolet Pickup '56 Chevrolet Belair '04 Chevrolet Astro '95 Chevrolet Blazer

11-24-2005, 11:22 AM	#2
jku72 Registered User Join Date: Jan 2002 Location: cornville, maine Posts: 659	Re: Trailer brakes It could be either. My experience says that the brake wire is a red one, with the ground black, in your case, I would do a temporary hook up one way, try the brake, if it works, try it the other way, and see which way works best. Dont rely on grounding through the hitch. This is my non professional opinion. __________________ jku Cornville, Maine 68 C10 burb 42 Willys MB 46 Dodge WF-32 1.5 ton 53 & 56 Olds' 60 Cadillac 22 Dodge Brothers

11-24-2005, 11:29 AM	#3
LUV2XCLR8 The LuvShack Garage Join Date: Jan 2004 Location: Maple Grove, TN (West Side) Posts: 30,468	Re: Trailer brakes Without trial and error there is no way to be sure __________________ Owner/Op: "TN Classic Transport Carriers" The Toy: "Square Vette" 72 Hybrid Blazer Toy Barn: "LuvShack" 40 x 60 x 20 Shop Tow Piggy:"Maddy" 88 Silverado 3500 Hauler: "Feathers" 14 Aluma 8218T

11-24-2005, 11:31 AM	#4
nitor Too many projects Join Date: Aug 2002 Location: Morrow, OH Posts: 344	Re: Trailer brakes Thanks for the reply guys. Happy Thanksgiving. __________________ Jim '55 Chevrolet Pickup '56 Chevrolet Belair '04 Chevrolet Astro '95 Chevrolet Blazer

11-24-2005, 12:16 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Trailer brakes A couple fuses in your power and ground wire for testing reasons wouldn't be a bad idea.

11-24-2005, 10:08 PM	#6
jimfulco Registered User Join Date: May 2003 Location: Shreveport LA Posts: 3,170	Re: Trailer brakes Do you have a brake controller on your truck? If not, you might not want to hook the brakes up, because the trailer brakes might lock up prematurely, causing the trailer to try to pass you. Last edited by jimfulco; 11-24-2005 at 10:09 PM.

11-24-2005, 10:38 PM	#7
Boog laying low Join Date: Mar 2001 Location: Searcy, Ark. USA Posts: 13,535	Re: Trailer brakes Nitor you do have a brake controller in your truck don't you? The trailer brakes will ground through the connector not the frame. Not a guarantee but some trailers use the black for the positive and white for the negative. Not all brake wires are the same color. If you hook it up wrong you could destroy your brake controller. How about with the trailer removed from your truck place a battery near the front of trailer and run a couple of jumper wires to those brake wires using an inline fuse on each wire. By touching the two wires to the battery posts it should activate the brakes. You should hear a solenoid type of click when activated. Reverse the wires at the battery and touch them again. It may not make any difference which wire is hot as the brakes are magnetically charged when the power is applied. Are there any RV dealers in your area? Someone there could be of a lot of help as they hook up these all the time. __________________ Boog 69 Chevy stepside, 358/T350, 4.11 posi, 4.5/4 drop, rallys, poboy driver primer is finer 91 Chevy sportside, Tahoe, Yukon & GMC Crewcab All GM..'nuff said. I stand for the flag and kneel at the cross

11-24-2005, 10:38 PM	#8
CG BlahBlahBlah Join Date: Feb 2002 Location: Wa. Posts: 20,035	Re: Trailer brakes i agree with jim on this one. i purchased a trailer with brakes on both axels. first time i used it when you turned on the blinker the trailer brakes went on and off with the signal. i decided to rewire the entire trailer. i did a google search and there are a ton of sites with diagrams for wiring trailers. i ended up going to an rv supply store to pick up some lights and stuff and those guys were a wealth of knowledge helping me rewire my trailer.

11-24-2005, 10:41 PM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Re: Trailer brakes I automaticly assumed we were talking surge brakes. If there is no contropller...then leave them alone and disconnected



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