Just installed a trailer hitch from etrailer.com. now working on the wiring harness from tekonsha for the volvo.
Trying to figure out were you can go through the firewall with the wire th h as t has go make it to the battery of the car.
I originally checked my car out by volvo and the dealership wanted nearly $400 just for the wiring harness for the car, then 3 hours of labor.
I have done all the connections of the harness in the back of the car and the running of the wire up to the dash at this point. Need help to get through firewall to battery.
Thanks.

Use any existing hole in the firewall.

My 1995 has the battery wire coming out of the bottom drain plug in the rear, then the wire follows the brake line to the front, zip tied to the line. Don't forget the fuse holder.
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Keeping it running is better than buying new

That is the problem at this point.
I was under the dash looking and could not find any access.
It is so heavily padded and carpeted.
I've never seen it like this in a car before.
And when I look at the engine compartment firewall there is next to no room for even a hand to get into.
hmm.