Trying to run power wire through firewall on passenger side

Post by **SonicAdventure** » 10 Apr 2017, 14:34

I'm in the process of hooking up my CB in the map pocket but the one thing holding me back is an inability to find a way to route the power wire to the positive battery terminal. I'm going to keep my ground wire real short and bolt it to the frame using one of the bolts holes that held the knee bolster in place. But I just can't seem to find a way to get a wire out of that area and into the engine compartment. I thought about running it up the duct where the cabin air filter is, and maybe running the wire under the black plastic cover where the wiper motor sits. Has anyone else tried running a direct to battery power wire from the passenger side area on one of these cars? Thanks.

Post by **bmdubya1198** » 10 Apr 2017, 15:38

I'm not sure of anywhere on the passenger side to go through the firewall, but there is a rubber grommet on the driver's side near the brake pedal that you can go through it the wire is long enough. That's where I have my boost gauge routed.

Post by **SonicAdventure** » 10 Apr 2017, 18:35

bmdubya1198 wrote: ↑10 Apr 2017, 15:38 I'm not sure of anywhere on the passenger side to go through the firewall, but there is a rubber grommet on the driver's side near the brake pedal that you can go through it the wire is long enough. That's where I have my boost gauge routed.

About where does it come out on the engine compartment side of the fire wall? That might work as I can run it over the heatercore and out the brake grommet pretty much a b-line to the positive terminal from there

Post by **bmdubya1198** » 10 Apr 2017, 19:03

It comes out just under the main fuse box, near the brake booster. Pretty direct route to the battery from there.

Post by **BEJinFbk** » 11 Apr 2017, 00:42

No need to leave the passenger compartment.
Two Words: Accessory Connector.

It's right there with up to 30 amps available.

Didn't you already ask about this...?

viewtopic.php?f=1&t=80606

Post by **SonicAdventure** » 11 Apr 2017, 20:04

BEJinFbk wrote: ↑11 Apr 2017, 00:42 No need to leave the passenger compartment.
Two Words: Accessory Connector.

It's right there with up to 30 amps available.

Didn't you already ask about this...?

viewtopic.php?f=1&t=80606

Yeah I did but all the CB pros say for best performance get the power straight from the battery so it eliminates any possible "noise" from the car's electronics. Believe me if I thought I could just wire it to the accessory bank I would but I'm going through a lot of work to install this radio and I want top performance out of it.

If any one else on here can testify to success wiring a CB to the accessories connector, I will do that instead.

Post by **BEJinFbk** » 11 Apr 2017, 23:15

First of all, if you're running from the glove box to the battery,
it doesn't really matter where you decide to penetrate the firewall.
The distance will still be pretty much the same. Volvo gives you a
nice, clean, water-tight, pre-existing location, why not use it?

Honestly, though, I'd just use the accessory connector.
It's a 4 watt CB in a modern vehicle - You'll be fine.
If the guys you're taking your cues from knew how well
designed this feature is, my guess is they'd be on board.
I woulda killed for this kind of convenience back in the day!

If it helps, I used to install a lot of radios in fleets of trucks,
all much "noisier" that a P80 Volvo. All of those picked up CB
power directly from the fuse block on the firewall - No Noise.
For the 100 watt VHF's, sure, straight to the battery with the
Big Red Wire, but the low current power legs still went to
the same fuse/distribution block - No prob.

If you're worried about using the easily available power,
go ahead and get your antenna installed and test drive it.
Problems? Go ahead and make that run out to the battery.
( And always remember to turn the CB off...)

And if you're concerned about any voltage drop from the
switched lead, use it to control a relay that feeds your radio
from the big B+ lead also available at the accessory connector.
But with the amp or so you'll draw with a legal CB... ?
I don't that'll be an issue.

IMHO, you're bigger concern is the antenna. If you're really serious
about the best possible installation, dead center in the roof will get
you the best possible performance. But you'll need to mount it and
get the cable there. With these cars, a 3/4" hole and an NMO mount
will be your best bet. ( Mag mounts are awful and will hose your paint ).

https://www.amazon.com/Laird-Technologi ... le+sawHS34
http://www.ebay.com/itm/PCTEL-Maxrad-3- ... SwzgBY4ETe

But if you go for it, look into the MaxRad MLB2700 FTW!
http://www.ebay.com/itm/Maxrad-MLB2700- ... Sw-YBXGJsa

Post by **SonicAdventure** » 14 Apr 2017, 15:41

Hey I really appreciate your detailed reply BEJ. Sounds like you have quite a bit of experience.

I located the accessory connector and I think I will go ahead and give it a shot. But - I don't have the foggiest idea how to connect a wire to it. I pulled off the end where you can connect the wires and I see how it folds down to accept a wire. But on the female end it looks like the wires have little metal tips on them. How are you supposed to prep the wire in the male end, just strip a 1/2" of it and lock it into the holder? Also, is the accessory connector designed to just accept positive wires and then it's ok to ground my negative to the car frame over near the radio?

Teddy1975 · Post by **Teddy1975** » 15 Apr 2017, 01:26

If it was me, I'd simply cut the big red wire on pin 1 of the plug, then either solder my own connector on the wire or solder the wire from the radio directly onto it. It should be fine to ground the radio directly to chassis.

If you should experience problems with electrical interference, it's easy and low cost to make your own filter.

Good luck,
Teddy

Post by **SonicAdventure** » 15 Apr 2017, 08:17

Teddy1975 wrote: ↑15 Apr 2017, 01:26 If it was me, I'd simply cut the big red wire on pin 1 of the plug, then either solder my own connector on the wire or solder the wire from the radio directly onto it. It should be fine to ground the radio directly to chassis.

If you should experience problems with electrical interference, it's easy and low cost to make your own filter.

Good luck,
Teddy

Is the large red wire in #1 position the wire with the 30 amp fuse?

Can I buy a metal tip to solder onto my CB power wire that will enable me to use the accessory adapter correctly? I really don't want to cut any of the wires and soldering with my head up under the dashboard doesn't sound like much fun.

I would assume if Volvo went to the lengths of designing and implementing this accessory connector they would have made some type of metal wire cap available somewhere along the line that would enable the user to crimp or solder their wire and insert it into the male adaptor so it would truly be a plug and play scenario.