Trailer wiring,anyone know

century3045 · Jun 8, 2006

you can tap anywhere, you can even pull a wire from the brake light itself, doesn't really matter as long as it activates by depressing the pedal. Dont pay a bunch for a brake unit, the 50 dollar ones work as wel as the 200.00 ones. I have wired up hundreds of trailers and vehicles for brakes. This used to be my side-line. That is correct, if the vehicle had a towing package, thje wires are all there, just splice into them

century3045 · Jun 8, 2006

you can tap anywhere, you can even pull a wire from the brake light itself, doesn't really matter as long as it activates by depressing the pedal. Dont pay a bunch for a brake unit, the 50 dollar ones work as wel as the 200.00 ones. I have wired up hundreds of trailers and vehicles for brakes. This used to be my side-line. That is correct, if the vehicle had a towing package, thje wires are all there, just splice into them

jwstewar · Jun 8, 2006

( On a 95 you will need to wire it the old fashioned way, no fancy premade plugs under the dash. )

I agree with this. I had to tap the brake switch wire and run wires from the battery to the controller and then on to the rear bumper when I hooked up mine on my '97 K1500. Yes, it had the heavy duty tow package - but GM didn't do any of the wiring. Heavy duty tow package consisted of hitch, high capacity air cleaner, transmission cooler, and locking rear differential (G80 RPO /forums/images/graemlins/smile.gif) Much nicer on my '99 (the first year for GM to do that) plug a pig tail in under the dash, insert a few under the hood and you were done. All plugs were already to the rear and in the case of my truck already to the front of the bed for fifth wheel or gooseneck.

jwstewar · Jun 8, 2006

( On a 95 you will need to wire it the old fashioned way, no fancy premade plugs under the dash. )

I agree with this. I had to tap the brake switch wire and run wires from the battery to the controller and then on to the rear bumper when I hooked up mine on my '97 K1500. Yes, it had the heavy duty tow package - but GM didn't do any of the wiring. Heavy duty tow package consisted of hitch, high capacity air cleaner, transmission cooler, and locking rear differential (G80 RPO /forums/images/graemlins/smile.gif) Much nicer on my '99 (the first year for GM to do that) plug a pig tail in under the dash, insert a few under the hood and you were done. All plugs were already to the rear and in the case of my truck already to the front of the bed for fifth wheel or gooseneck.

redharley · Jun 8, 2006

Thanks guy's I knew I'd get a lot of info from all the wiring pro's out there.But here's the story, plugs all wired,brake controler installed all I need to do is attach the wire to the brake light switch wire.My question is this,is their a place other than the switch "which is a real PITA to get at"to get brake light power.You can not use the wiring which runs back to lights as this wire also contains turn signal power,as one of the earlier poster's said my tahoe does not have a towing package.I can use the brake light switch I just thought there would be a easier place and save some time.

redharley · Jun 8, 2006

Thanks guy's I knew I'd get a lot of info from all the wiring pro's out there.But here's the story, plugs all wired,brake controler installed all I need to do is attach the wire to the brake light switch wire.My question is this,is their a place other than the switch "which is a real PITA to get at"to get brake light power.You can not use the wiring which runs back to lights as this wire also contains turn signal power,as one of the earlier poster's said my tahoe does not have a towing package.I can use the brake light switch I just thought there would be a easier place and save some time.

Soundguy · Jun 8, 2006

( The controller takes the fixed voltage from the brake light circuit and varies the voltage applied to the trailer brakes with an inertia type switch." Not anymore. The brake light connection only tells the controller to start applying voltage from the battery connection. You will actually need to install an automatic reset circuit breaker for the main power feed.
)

Highbeam.. i think that is what he meant.. that the brake control provides th power for the brakes.. it does not take it from the brake switch line.. it merely uses that as a reference.

Oh.. at least on 2000 GMC's with a tow package.. there is no resetable CD.. it is a large 30A or 50A fuse that goes in a holder under the hood. ( my 98 dodge w/ tow package has the cb )

Soundguy

Soundguy · Jun 8, 2006

( The controller takes the fixed voltage from the brake light circuit and varies the voltage applied to the trailer brakes with an inertia type switch." Not anymore. The brake light connection only tells the controller to start applying voltage from the battery connection. You will actually need to install an automatic reset circuit breaker for the main power feed.
)

Highbeam.. i think that is what he meant.. that the brake control provides th power for the brakes.. it does not take it from the brake switch line.. it merely uses that as a reference.

Oh.. at least on 2000 GMC's with a tow package.. there is no resetable CD.. it is a large 30A or 50A fuse that goes in a holder under the hood. ( my 98 dodge w/ tow package has the cb )

Soundguy

Highbeam · Jun 9, 2006

The problem with using that fused line is that the fuse pops when you need it most, when you are trying to suck lots of juice for the brakes. The auto CB resets itself so that your brakes will come back and let you stop. My brake controller diagram was pretty specific in that you weren't supposed to use a fused power feed.

I cheated a bit since the 30 amp fused connection you speak of feeds my required 20 amp (might be 15) auto reset CB. Maybe thats what you meant, to use the 30 amp fused power line to power the 20 amp CB for the controller. The small auto CB should pop before the large 30 amp maxi fuse.

To the poster, I could tell you which wire they used on mine but not sure if it is the same as a 95. Maybe even take a picture. The brake switch must have been in a tight spot so they spliced into a wire right under the column. Maybe you can follow the wires to a more convenient place.

Good call on not using a brake light wire since the blinkers also could trigger your controller. There is one wire though, on mine it is white, that feeds the third brake light. I use it to power the thrid brake light in my canopy. It is a white wire back there that does not activate with the hazards, only brakes.

Highbeam · Jun 9, 2006

The problem with using that fused line is that the fuse pops when you need it most, when you are trying to suck lots of juice for the brakes. The auto CB resets itself so that your brakes will come back and let you stop. My brake controller diagram was pretty specific in that you weren't supposed to use a fused power feed.

I cheated a bit since the 30 amp fused connection you speak of feeds my required 20 amp (might be 15) auto reset CB. Maybe thats what you meant, to use the 30 amp fused power line to power the 20 amp CB for the controller. The small auto CB should pop before the large 30 amp maxi fuse.

To the poster, I could tell you which wire they used on mine but not sure if it is the same as a 95. Maybe even take a picture. The brake switch must have been in a tight spot so they spliced into a wire right under the column. Maybe you can follow the wires to a more convenient place.

Good call on not using a brake light wire since the blinkers also could trigger your controller. There is one wire though, on mine it is white, that feeds the third brake light. I use it to power the thrid brake light in my canopy. It is a white wire back there that does not activate with the hazards, only brakes.

jwstewar · Jun 9, 2006

( Oh.. at least on 2000 GMC's with a tow package.. there is no resetable CD.. it is a large 30A or 50A fuse that goes in a holder under the hood. )

Are you talking about the one you have to add in? If so, that is for the constant power supply aka battery charge. There still may be a fuse instead of CB, I'm not sure. Haven't investigated it that far.

jwstewar · Jun 9, 2006

( Oh.. at least on 2000 GMC's with a tow package.. there is no resetable CD.. it is a large 30A or 50A fuse that goes in a holder under the hood. )

Are you talking about the one you have to add in? If so, that is for the constant power supply aka battery charge. There still may be a fuse instead of CB, I'm not sure. Haven't investigated it that far.

AlanB · Jun 9, 2006

I will copy some of my Tekonsha Prodigy stuff here, I thought You could use the same as my 98 Chevy but yours is different by these instructions.

This is what it say's to do.

95-96 All GM tow vehicles

The brake controls red (stoplight) wire splices into a specific white wire on a 10 pin connector. This connector is located to the left of the steering column. It is coming from the main loom of wires going into the instrument panel. The connector is white and is wrapped with grey foam tape; it will have two white wires exiting the connector. The correct wire is the white wire located in corner (f position) of the connector. splicing into this specific wire will eliminate any problems with electrical circuits associated with ABS or the cruise control.

Just for note. The tekonsha folks are very helpful in getting their stuff working / hooked up.

I have a couple of their Prodigy brake controllers installed and am very happy with them.

AlanB · Jun 9, 2006

I will copy some of my Tekonsha Prodigy stuff here, I thought You could use the same as my 98 Chevy but yours is different by these instructions.

This is what it say's to do.

95-96 All GM tow vehicles

The brake controls red (stoplight) wire splices into a specific white wire on a 10 pin connector. This connector is located to the left of the steering column. It is coming from the main loom of wires going into the instrument panel. The connector is white and is wrapped with grey foam tape; it will have two white wires exiting the connector. The correct wire is the white wire located in corner (f position) of the connector. splicing into this specific wire will eliminate any problems with electrical circuits associated with ABS or the cruise control.

Just for note. The tekonsha folks are very helpful in getting their stuff working / hooked up.

I have a couple of their Prodigy brake controllers installed and am very happy with them.

Slamfire · Jun 9, 2006

I just hooked up a Prodigy last week. I went to get one of the 7 wire connectors and discovered there is a six pin connector for use if you don't need a backup light. Now all I have to do is check out and probably overhaul the electric brakes on this ancient (1968) trailer. /forums/images/graemlins/tongue.gif

Slamfire · Jun 9, 2006

I just hooked up a Prodigy last week. I went to get one of the 7 wire connectors and discovered there is a six pin connector for use if you don't need a backup light. Now all I have to do is check out and probably overhaul the electric brakes on this ancient (1968) trailer. /forums/images/graemlins/tongue.gif

Soundguy · Jun 10, 2006

( The problem with using that fused line is that the fuse pops when you need it most, when you are trying to suck lots of juice for the brakes. )

That fuse is rated for the full pull of the brakes + a large percentage, but rated below the rating of the wire.. etc.. exactly what the fuse needs to be.

( My brake controller diagram was pretty specific in that you weren't supposed to use a fused power feed.
)

I refered to the section in my GM manual for adding the controller to the option plug under the dash. GM provided me with the fuse and a stub wire harness. The large fuse.. at least for -my- vehicle controlled controller power as well as battery power.. no CB in the path...

Soundguy

Soundguy · Jun 10, 2006

( The problem with using that fused line is that the fuse pops when you need it most, when you are trying to suck lots of juice for the brakes. )

That fuse is rated for the full pull of the brakes + a large percentage, but rated below the rating of the wire.. etc.. exactly what the fuse needs to be.

( My brake controller diagram was pretty specific in that you weren't supposed to use a fused power feed.
)

I refered to the section in my GM manual for adding the controller to the option plug under the dash. GM provided me with the fuse and a stub wire harness. The large fuse.. at least for -my- vehicle controlled controller power as well as battery power.. no CB in the path...

Soundguy

Soundguy · Jun 10, 2006

( If so, that is for the constant power supply aka battery charge. There still may be a fuse instead of CB, I'm not sure. Haven't investigated it that far. )

All i can tell you, is that the BIG fuse that GM provided me for my tow package had to be in for my controller to even turn on.. thus that tells mee that brake power ran thru that fuse. Looking at the fuse diagram on the plastic shield covering the engine compartment fuse tray, that big fuse is directly in line with battery power.. no upstream circuit breakers. Not even an ignition relay... I can't speak for any other years or make / models of trucks. I know my dodge has the circuit breaker.

Soundguy

Soundguy · Jun 10, 2006

( If so, that is for the constant power supply aka battery charge. There still may be a fuse instead of CB, I'm not sure. Haven't investigated it that far. )

All i can tell you, is that the BIG fuse that GM provided me for my tow package had to be in for my controller to even turn on.. thus that tells mee that brake power ran thru that fuse. Looking at the fuse diagram on the plastic shield covering the engine compartment fuse tray, that big fuse is directly in line with battery power.. no upstream circuit breakers. Not even an ignition relay... I can't speak for any other years or make / models of trucks. I know my dodge has the circuit breaker.

Soundguy