towing electrical hookup

Sufbug · Post by **Sufbug** » 19 Oct 2021, 08:55

Hello everyone.

So, first off, thanks for the timing belt support !

went form NC to FL with no issues…..and had her revving to 4k no worries, and up to 102 mph ( hey its Florida ) but only for a moment.

thanks to Paul and to Shane of the Red Wagon Squadron for the live phone support.

and to others here for forum support!

ok, so now I am installing a hitch, and then have to hook up the electrics.

som towing web sites have this module and blah blah for 60 ubukcs, and say its because the trailer lights will stress the electical system in the Volvo 1998 V70 FWD GLT that I own…..

Matt, I see you went a long way with your Volvo wagon. I have to do the same thing… DC to Orlando FLA, about 950 miles.

how did you ( or anyone) wire in the wiring harness on the car side?

any links or threads that may assist?

thanks,

Big Al

Sufbug · Post by **Sufbug** » 20 Oct 2021, 07:54

Anyone got anything?

If not that's cool I will search it on YouTube and on the other Volvo sites and on this site and I'll post some links here to make it easier for the next guy!

Have a good day!

Post by **BEJinFbk** » 20 Oct 2021, 12:58

There are a couple of good reasons to go with the module.
The obvious is that you’re pulling more current through the
lighting system than it was designed for. Fuses, switches,
relays and wire gauge were all intended for the factory
lamps on the car.

The less obvious reason is the lamp out indicator system
for your tail and, IIRC, brake lights. They’re calibrated for
the number of lamp filaments that ship with the car.
Also, loading the turn signal flasher with more current
can cause problems.

And the biggest reason, at least for anyone following
behind you working on the car, the Volvo OEM trailer
interface is pretty much plugNplay - No harness hacking.
Can’t speak to any aftermarket modules, though.

Post by **Eddystone** » 21 Oct 2021, 12:12

I've looked into this, as well, and I would go with the OEM purposely designed harness adapter - assuming I could find one. Sufbug might be referring to universal adapters sold on places like Amazon. They will isolate your system and only use the original wires as "trigger signals" if the adapter is a good one for all the reasons BEJinFbk mentioned.

I wish the trailer hitch on the P80 was as easy to do as it is on my 940. If I recall, the 940 has four reinforced threaded hole right there in the body and you just screw the hitch on.

Post by **BEJinFbk** » 21 Oct 2021, 15:25

With any isolation module option, you’ll still
need an ample power supply for the heavy lifting.

Fun Fact! These wagons are prewired for a
6 disc CD changer in the rear left behind the
wheel well. The six pin mini-DIN to the head
unit may not be present, but you should still
find the two lead power connector taped down
back there. IIRC, you get a ground and a B+
lead thats’s good for 15 or 20 amps.

Sufbug · Post by **Sufbug** » 23 Oct 2021, 09:26

Hey everyone thanks I will check all this out and report back!

Hitch is going on today....

Post by **kallekula** » 23 Oct 2021, 10:53

Autozone / oreilly sells a kit. Think it came with instructions, otherwise check youtubes.