Available Wiring Harness Differences on 1988 Ford Ranger and Current Draw from Vehicle

Updated 02/04/2015 | Published 02/03/2015

Question:

Will your plug n tow ready connector affect the voltage drawn from the battery through the wires to the rear lights? Do I need to worry about a fuse? Meaning, I have heard that some guys run an extra hot wire and fuse from the battery to the connector for the trailer. Otherwise the rear lights on the truck and trailer will both be dimer because its drawing from the same wire. Or is this dependent on the electrical draw of the type of trailer? Meaning the lights may not dim at all if it is a small trailer with fewer lights than a larger trailer with more lights.

asked by: Joseph L

Helpful Expert Reply:

Both of the 4-pole wiring harnesses available for your 1988 Ford Ranger can be seen on the provided link. Both are custom-fit types that plug in to connectors on the vehicle and all are passive, meaning that they do NOT require a 12V power feed directly from the vehicle's battery. That type of powered converter requires this separate power feed to provide the operating power for your trailer's lights.

Powered converters use the tail light wiring on your truck just to trigger the converter's output, but again that output comes from the battery connection. In your case the power for the trailer lights will be drawn through the truck's own wiring. The engineers at Curt and Hopkins have determined that the truck's wiring has enough capacity to deliver the operating current for the trailer lights so a powered converter is not needed.

You are correct that the type and total number of lights on the trailer will determine if there will be any negative effects on the brightness of the truck's lights. It is certainly possible to overload either a passive harness or an active powered one. If one were to add a large number of additional lights to a trailer, especially if there were the more power-hungry incandescent type, then it would be possible that light output at the truck could suffer.

This can be avoided by using LED lighting that requires only about 1/10th the power needed for incandescent bulb fixtures. I have included a link to our main page for LED trailer lighting products.

expert reply by: Adam R