trailer wiring on a 97 blazer

[jkdon]

can anyone help me with this one, I've searched other threads but haven't found much. I have a 97 blazer finally have a little camper to pull behind it. thought I could walk into autozone buy one of those easy pop a tail light out put a T connector in and I would have trailer lights. I guess from what they tell me it is not available for this truck. I have to splice into the harness with one of those 4 pin cheap always too short wiring harnesses. can anyone tell me which wire color on the truck goes with those standard trailer harnesses. I have yellow, brown, green and white to work with.

thanks alot

Jkdon

[MT-2500]

Originally Posted by jkdon

can anyone help me with this one, I've searched other threads but haven't found much. I have a 97 blazer finally have a little camper to pull behind it. thought I could walk into autozone buy one of those easy pop a tail light out put a T connector in and I would have trailer lights. I guess from what they tell me it is not available for this truck. I have to splice into the harness with one of those 4 pin cheap always too short wiring harnesses. can anyone tell me which wire color on the truck goes with those standard trailer harnesses. I have yellow, brown, green and white to work with.

thanks alot

Jkdon

Color codes
White or black is the ground.
Green is right turn.
Yellow is left turn
Brown is tail lights.

Splice in connectors will give you problems from moisture that will corrode the wiring and led to light bnot working back there.
If you have to splice in solder and seal the wiring with sealer at the solder joints.
Or better yet find a parts place or dealer that has the plug in the wiring trailer plug in wiring.
Easy to just plug in and you will have a lot less corroded wiring back there.
MT

[joeuser742]

Not sure what you are asking, but you need all 4 wires in order to have all the lights working on the trailer. The previous owner hooked up the harness on my truck, but doesn't work right. The truck might need something special, such as, a relay or some sort of switching device.

[mike2004tct]

Originally Posted by jkdon

can anyone help me with this one, I've searched other threads but haven't found much. I have a 97 blazer finally have a little camper to pull behind it. thought I could walk into autozone buy one of those easy pop a tail light out put a T connector in and I would have trailer lights. I guess from what they tell me it is not available for this truck. I have to splice into the harness with one of those 4 pin cheap always too short wiring harnesses. can anyone tell me which wire color on the truck goes with those standard trailer harnesses. I have yellow, brown, green and white to work with.

thanks alot

Jkdon

Just a quick note here, On my '97, a wire harness was provided from the factory for hooking up a connector - the wires were left pig-tailed and bundled in the area that a trailer hitch would mount. Crawl under your truck and look for it, mine was tucked up above the bumper in the middle of the bumper. There was a label on mine telling what the colors are associated to each light.

[spano]

I just finished that same wiring and the wiring harness SHOULD be tucked under the rear bumper near the spare tire on the driver side (4 door). All markings are correctly stated above and also the manual (may not have) states what teh other colors are for. If you are going to go thru that I suggest connecting the 7 pin and you could always get the 4 pin adapter. The 7 pin allows for running lights, reverse lights, electric brakes, and 12V power for a battery charge.

BTW - Mike2004tct (or anyone) where did you connect the red to (constant 12V) inside of your vehicle? The book says there is an in-line fuse near the fuse panel but I have yet to find it. All other wire work accordingly.

[mike2004tct]

Originally Posted by spano

BTW - Mike2004tct (or anyone) where did you connect the red to (constant 12V) inside of your vehicle? The book says there is an in-line fuse near the fuse panel but I have yet to find it. All other wire work accordingly.

My memory does not serve me well, because I don't recall having to hook up/re-connect anything on mine. I just attached a 4 pin connector to the pig tails (It was 9+ years ago )

[jkdon]

thanks alot guys, I'm glad I asked about this one I thought for sure I was digging into the tail light assembly. I am definitely taking your advice spano I will mount the 7 pin while I'm in there. The trailer I have does have brakes but I'm not sure if they work yet. If I wire the 7 pin off the factory harness under the back of the truck, don't one of those wires have to go to a controller up front before the electric brakes will get power on the trailer?

thanks again
jkdon

[spano]

I don't know for sure, I think the controllers are advanced. This may workoff a signal to apply pressure? There is probably a blue wire attached to the one I can't find so you can hook a controller. Somebody else may know more.

[Hunter1]

If your blazer is prewired you might have better luck at a boating store for the T connector. As for the brakes, on most small trailers there is a brake booster located on the tounge of the trailer that uses forward momentium of the trailer to activate a switch for the brakes. (as the truck starts to slow down the trailer moves forward on the ball activating the switch.) This setup doesn't need a controller. Otherwise you'll need the 7 pin as stated earlier. Happy camping!!!!

[jkdon]

Hunter I think I see something like that. I thought the thing on the trailer tongue was some type of break away device. there is a small battery inside of the trailer. I would like to install the controller, can I eliminate all that other stuff and tie the controller into the chevy blue wire and send the signal directly to the brakes. The wiring on this thing is a nightmare.

thanks
Jkdon

[Hunter1]

to answer your question... I would not use a brake controller. the pressure switch on the trailer should do the job. Basiclly it breaks down like this. The braking system that requires a seperate controller usually runs trailers that are greater than 5000 pounds which in MY OPINION is too heavy for our blazers. That said I think you would be better served using the existing braking system. Besides the wiring is a bit of a pain.

[OverBoardProject]

Those trailers with the brake booster on the tounge of the trailer will break the bank
http://www.easternmarine.com/em_stor...rakes_hyd.html

Electric brake systems are pretty affordable.
http://www.easternmarine.com/em_stor...rakes_ele.html
not to mention easy to find used parts for (compaired to the hydralic systems)

You can even fine tune the braking with the electric system from inside the cab.

[Cruize]

I'm planning on installing a Hoppy 7 / 4 pin connector for my trailer wiring. This has the round 7 pin connector as well as the straight slot 4 pin connector all in one assembly. My local parts store has it for $25. And my 95 Blazer (4 door) has the pigtail under the bumper like others have mentioned.

Originally Posted by jkdon

Hunter I think I see something like that. I thought the thing on the trailer tongue was some type of break away device.

Is the "thing" bolted to the side or top of the trailer tongue? And does it have two electrical wires going into it and a pin that you can pull out? If so, this is the break-away switch that you mentioned. The pin should have a cable attached to it. The cable is then connected to the tow vehicle. In case the trailer "breaks away" from your Blazer, the pin pulls out of the switch, allowing the two contacts inside it to touch and complete the braking circuit. The battery on / in your camper supplies the power to activate the brakes and stop the camper.

there is a small battery inside of the trailer.

Make sure the battery has a proper charge. My brother's landscaping trailer had a small dry-cell battery for the break-away switch. The thing was dead in a year or two even though it never got used. I think he's gonna put either a car or RV battery on there so he can charge it and not need to replace the small dry-cell battery every year or two.

As far as electric brake controllers, I know there are ones that you mount inside the car and there are ones that get mounted directly to the trailer tongue. I assume the latter one senses the change in momentum as the tow vehicle slows and the trailer wants to maintain its speed. Somehow this "black box" knows when you are slowing down and it applies the brakes on the trailer. This is similar to what Hunter1 was saying, except this doesn't have anything that touches the ball. It just sits there, bolted to the tongue. I don't have any clue how well these work. The trailer I borrowed had one of these on it, but it didn't work for some reason. Could have been broken wires, rusty brakes, etc. (I didn't need it anyway since I had a 4-1/2 ton truck.)

[jkdon]

thanks alot for all the help

I installed the same thing that cruize mentioned. It wires up nice to the factory pig tail. what is weird is that the round connectors do not have a space for the yellow wire which is the left turn so i connected it to the terminal labeled black and made sure I found the left turn wire on the trailer. one thing I learned is don't trust the trailer wires, go with the factory harness on the blazer and find the wire on the trailer that works. still waiting on the controller for the truck. ebay $28.00. I had two wires left over after the job. A 12ga red and a light guage white. book says charging wire which must connect to the brake away battery and the white says auxillary? anyways can't wait to get the electric brakes working and the 97LS with a 135K will be chased by a 1977 1500lb Scotty. The thing pulls it up steep hill on my way home and the speedo keeps climbing. Work Your Vortec!! (After you replace you lower intake gaskets)

Jkdon

[spano]

Did you have 12V on the red wire automaticly or is it dead? just trying to see if yours was pre-wired and I need to find a blown fuse. Congrats on getting it done....