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07 SR5 Prerunner Acc
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Discussion Starter #1 (Edited)
:disappoinNeed some help on trailer lights

I bought a 07 2.7L tacoma prerunner and had the dealership install the toyota accessory hitch and the trailer wiring kit. I hooked up a trailer for the first time yesterday, and I didn't get any running lights. The brake and turn signals work fine on the trailer. I checked for power coming out of the 4 pin on the truck and I am getting no power from the running lights but do get power for the turn/brake lights. Checked fuses at both fuse boxes and did not find any bad. Is there a fuse in-line somewhere? Also, Since my truck did not come with the tow package, were there supposed to be extra fuses added in slots when the wiring kit was installed at the dealership?

Any help would be greatly appreciated.
 

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I had a similar problem hooking up my dad's trailer to my truck. The box trailer worked fine, but on the open trailer, I couldn't get any of the lights to work. They worked fine on both of his trucks (Chevy's), but we couldn't figure out why they wouldn't work on mine. We checked all the bulbs, connections, even traced the wiring.
 

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07 SR5 Prerunner Acc
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Discussion Starter #3
Yes, It's weird. I get power out of the 4 pin on the truck for the brake and turn signals but I do not get any power out of the 4 pin on the truck for my parking / running lights?
 

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I dug out the booklet that came with my towing harness assembly. It shows a fuse called fuse towing tail 30A. This power then goes to a relay that is turned on by the light switch. There is another fuse towing 30A that is for the brake light/turn signal converter. The two fuses are located in the big fuse/relay box behind the battery. One is the middle fuse in the bank on the rear. The other is shown directly across the box but turned 90 degrees. it is the second closest to the center of the fuse box from what I can tell. Just went out and looked. They are the only dark green 30A fuses in mine. Yours may be different. If you switch them see if the symtom goes to the blinkers. Also there is a relay in there on the back side, 2nd from right looking from front.
John
PS- you should make sure the dealer gives you the trailer harness publication that came with it.
 

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07 SR5 Prerunner Acc
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Discussion Starter #5
I dug out the booklet that came with my towing harness assembly. It shows a fuse called fuse towing tail 30A. This power then goes to a relay that is turned on by the light switch. There is another fuse towing 30A that is for the brake light/turn signal converter. The two fuses are located in the big fuse/relay box behind the battery. One is the middle fuse in the bank on the rear. The other is shown directly across the box but turned 90 degrees. it is the second closest to the center of the fuse box from what I can tell. Just went out and looked. They are the only dark green 30A fuses in mine. Yours may be different. If you switch them see if the symtom goes to the blinkers. Also there is a relay in there on the back side, 2nd from right looking from front.
John
PS- you should make sure the dealer gives you the trailer harness publication that came with it.

Unfortunately when I purchased the truck back in July I did not get the trailer harness publication, only the install instructions for the hitch. Are the fuses you mention supposed to come in the trailer harness kit? Reason I ask is because my fuse box behind the battery does not have Towing Tail 30A (Trailer lights), or Towing 30A (Towing Converter). Also there is no relay in the spot marked Towing Tail.

Weird thing is even with no fuse in the Towing 30A (Towing Converter) slot, I still have turn signals and brake lights?

I do see a power line that is fused and connected to the battery which seems to run all the way back to the left rear turn signal. Is there maybe a converter box back in the left rear light that is fused?

Thanks fot the help!:)
 

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Sounds wrong. Mine is '06 though. I wouldn't think they would do things much different. Sounds like maybe they just straight wired it which would by-pass any protection that the harness kit provides. If your trailer shorts using the kit, it will only fry the trailer section. If it is straight wired you risk frying your truck wiring. I wouldn't think they would do this. I would give the dealer a call tomorrow. They should make it right. You'll need to take it in to make sure they have installed they complete kit. Find out the part number for the harness kit. If it's the same maybe I can mail you a copy of the install stuff. You can compare it to what you have. The fuses and relay come with the harness kit.
John
 

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07 SR5 Prerunner Acc
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Discussion Starter #7
Sounds wrong. Mine is '06 though. I wouldn't think they would do things much different. Sounds like maybe they just straight wired it which would by-pass any protection that the harness kit provides. If your trailer shorts using the kit, it will only fry the trailer section. If it is straight wired you risk frying your truck wiring. I wouldn't think they would do this. I would give the dealer a call tomorrow. They should make it right. You'll need to take it in to make sure they have installed they complete kit. Find out the part number for the harness kit. If it's the same maybe I can mail you a copy of the install stuff. You can compare it to what you have. The fuses and relay come with the harness kit.
John

I will have to call the dealership tomorrow and get the part number. Unfortunately, I have moved 350 miles north of where I purchased the truck, so I may have to take it in to the local dealer. If it is the same kit, maybe they just forgot to put in the two fuses and relay. I was told that it was the wiring kit they use on all of the factory tacomas so I hope it was not straight wired. Thanks again and I'll let you know what I find out.
 

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07 SR5 Prerunner Acc
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Discussion Starter #8 (Edited)
Found the Problem!!!

Trailer light wiring on the trailer was mauled were it got caught between a frame bolt and the frame. Wiring was exposed and shorting out against the frame. That was the culprit. Now that I know what had caused the problem, I next went to the truck. I followed the fused power line (on the tacoma) that runs straight from the battery to the left rear lights on my tacoma. After opening up the left rear lights found three fuses for R, L, and running lights for the trailer. The running light fuse ( 7.5 ) was blown. I had a 5A fuse which I replaced it with. Have not got a chance to test it but feel confident that was the problem.

Thanks to all who helped!!!:)
 

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07 SR5 Prerunner Acc
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Discussion Starter #9
That was no Toyota Kit you got installed at the Stealership...could ya show use a pic of that hack?
Unfortunately It's all put back together at this point so I don't have much to take a picture of. Essentially, what I found was a power line coming off the positive battery cable that had a 20A fuse in the line right by the battery. That same line ran directly to the LR light housing where I found 3 seperate encapsed fuses for L, R, and running lights. To let you know, the 07 2.7L Access Cab PreRunner was not available with a factory towing package from the factory ( I think due to being a 2.7L ). I was told that the hitch and wiring harness I had put on at the dealership was considered a DH60 port installed item which meant that usually a technician would install it in Jacksonville, FL if the dealership receiveing the truck wanted it dressed that way. I believe this is the standard kit offered for people who buy a tacoma on the lot and then decide they want to have a hitch installed. In my case I had the same kit that usually would have been installed in Jacksonville, FL installed at the dealership. This package is not to be confused with the same package that comes on a tacoma with the standard factory towing package ( I believe only found on 4.0L models ). I hope this information serves someone else who may run into trailer wiring issues.
 
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