Which Missing Fuse in 2005 Chevrolet Tahoe Will Power 12V Trailer Circuit to Charge Trailer Battery

Question:

My 2005 Tahoe wont charge the trailer battery when Im towing it. The owners manual says I am missing a fuse. GM dealers will not tell me which one I need. Can you?

asked by: John S

Helpful Expert Reply:

Your 2005 Chevrolet Tahoe requires a 40-amp fuse be installed in the power distribution block under the hood. Please refer to the color photos in the linked article. These illustrate the location of the accessory fuse block in the engine compartment on the drivers-side.

I have also provided a photo showing the location of the required 40-amp fuse (amber-colored in the photo). Installation of the fuse (and possibly a required wiring connection to the positive power post) will enable transfer of 12V power to your trailer battery when towed by your Tahoe. In the article, please refer to Step 2 - Under the Hood, and follow the steps A through F shown under the photos.

Please note that this 12V circuit will not charge a depleted trailer battery, only maintain its level of charge. I often recommend the # CTEK56353. Instructions and video review links for this item are provided, along with an article on battery chargers.

Please note that the part you reviewed, the Hopkins Adapter 7 Pole to 4 Pole and 5 Pole, part # 37385, will not pass 12V auxiliary power to your trailer. This adapter is meant to mate a 7-way tow vehicle connector to a 4- or 5-pole trailer connector. 4-pole and 5-pole connectors provide trailer lighting functions only and do not carry 12V auxiliary power to a trailer.

expert reply by: Adam R