TBC question
02-06-2012, 04:31 PM
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TBC question
My 2011 f150 did not come with the TBC, I bought one, installed it and the relay and fuse that came in the bag with the pigtail. I had the computer flashed and it works great with my new travel trailer. The the problem I have it did not charge the battery on the trailer. The question I have how do I check to make sure I have power to the trailer at the plug or is there something I'm missing.
02-06-2012, 05:41 PM
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You need to buy a $26 dollar relay from ford and a 30amp short box style fuse. I just did this to my truck. I'm using my switched + lead on my 7 pin trailer plug to power my air bag compressor. When I get home I'll send you the part number and fuse/relay position for the under hood fuse box.
02-06-2012, 09:29 PM
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You'll need to open the hood and the fuse box above the radiator. You'll need a relay for relay location #9. Then you'll need a 30amp fuse for fuse position #21. This will give you 12v power when the ignition is turned on. The power shows up on your trailer 7pin harness on the lower right side of the plug. It is designed to charge you trailer batteries while your truck is running. I hope this helps. :-)
02-07-2012, 11:02 AM
#4
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My 2011 f150 did not come with the TBC, I bought one, installed it and the relay and fuse that came in the bag with the pigtail. I had the computer flashed and it works great with my new travel trailer. The the problem I have it did not charge the battery on the trailer. The question I have how do I check to make sure I have power to the trailer at the plug or is there something I'm missing.
You'll need to open the hood and the fuse box above the radiator. You'll need a relay for relay location #9. Then you'll need a 30amp fuse for fuse position #21. This will give you 12v power when the ignition is turned on. The power shows up on your trailer 7pin harness on the lower right side of the plug. It is designed to charge you trailer batteries while your truck is running. I hope this helps. :-)
02-07-2012, 01:50 PM
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The main thing to look for is relay 9 and fuse 21 are plugged in. If those aren't in place your trailer charge circuit doesn't work. My truck came with the 7 pin harness, but wasn't fused or relayed up. I guess this way you can visit ford to buy their $26 "hi-output" Ford specific relay. :-)
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02-08-2012, 11:19 AM
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The fuse and the relay came with the truck, they were a bag with a pigtail and the instructions in the glove box. They were installed and I checked them. I towed the trailer for about an hour and a half, I'm starting to wonder it the battery was not charged at all and the short trip wasn't enough to charge it. How do I check the 7-pin plug on the truck to make sure power is going to it. That is my question.
02-08-2012, 11:24 AM
#9
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There's a wiring diagram on the cover of the 7 way - take a volt meter from the 12v aux and ground it. You should see 12 volts.
There will only be power if the key is on - I towed a camper last year that had a very weak battery that wouldn't hold a charge, the interior lights would only work if the truck was running even after driving for an hour. Not the truck's fault, the owner of the camper just forgot to charge the battery over the winter.
There will only be power if the key is on - I towed a camper last year that had a very weak battery that wouldn't hold a charge, the interior lights would only work if the truck was running even after driving for an hour. Not the truck's fault, the owner of the camper just forgot to charge the battery over the winter.