The answer to this question depends on several factors such as: Whether the towbar was a factory fitted
unit fitted during
pre-delivery, a genuine brand
unit or an aftermarket
unit & who, where & when it was fitted...
The majority of towbars & the assosiated wiring out there are simply wired in to the rear tail light circuits such as:
- Trailer stop lights wired to vehicle stop light circuit in eighther of the rear tail lights.
- Trailer park lights wired to vehicle park light circuit same side as the stop lights, as above.
- Trailer number plate lights wired to vehicle park light circuit same side, as above.
- Trailer reverse lights (if fitted) wired to vehicle reverse light circuit same side, as above.
- Trailer left hand indicator wired to vehicle left hand indicator light circuit
- Trailer right hand indicator wired to vehicle right hand indicator light circuit.
This means that if fitted in this manner (as the majority are) the corrosponding vehicle light fuse will affect the trailer lights unless the is an inline fuse fitted to each single circuit (which cld be blown). This is very
uncommon & wld be a costly way to do it...
In some more modern cars that came from the factory
(not the dealership ie. pre-delivery) with the tow bar fitted as standard equipment
it is possible that there cld be a sepparate little fuse box or section in the main fuse box (the position of the fuse box/es shld be in your owners manual usually Under the bonnet, under the dash or behind font foot kick panels, & if you dont have an owners manual for your vehicle they are usually available to buy an aftermarket version or these days on the internet & often downloadable for free or @ a small charge).
All the best & I hope this is of some help...
Referances: Me, I am an auto mechanic.