AFR ran through driver side air vent

As I prepare for this motor swap, I only have 1 loose end. The placement of the AFR.

I have a 3D printed AFR holder for the driver side air vent and I plan on running the wires through the air vent system. I have spliced a power cable to power the AFR from the fuse box and the rest of the cable will be ran through the system, exiting the firewall which will lead to the oxygen bung at the lower portion of the downpipe.

Seems simple enough, but I need some help. Firstly, has anyone done this before and if so how. Secondly, finding a 740 air vent diagram online turns out to be somewhat difficult as the only thing that pops up are 240 and 940 air vent diagrams. Does anyone have one for a 740? Lastly, is there a section of the firewall on the passenger side of the car that can be punched out to run a cable through it or will I need to drill a hole in the firewall myself. Any help much appreciated!

As for my build:

It's a 1994 b230ft squirter block with 16,000 documented original miles on it. Running Yoshifab intake manifold isolators, Yoshifab catch can setup with vented oil cap, IPD turbo street cam, stock cam gear no retard or forward settings, big b20 valve springs (info courtesy of pbase and dl242gt), ported 1990+ exhaust manifold, 16T turbo, braided lines, NPR intercooler, modified AW71 (accumulator mod), upgraded JEGS trans cooler (trans -> 26000gvw -> stock cooler -> trans), 3" dp to 2.5" catless exhaust, sbabbs chipped lh2.2 ecu, stock injectors (for now w/ 3'' lh2.2 MAF on hand for resitor pack if needed), AFR and some other stuff I am probably forgetting.

Miata guys drill a hole in there HVAC vent tube for wires when installing gauges, might try that.

As far as running wires threw the firewall might be easier and look cleaner to put the wideband wires threw on the passenger side near the exhaust and run it under the dash to the vent.

On my 940, I routed the cable from the O2 sensor to the passenger side interior through an unused rubber plug right behind the downpipe. It appears it's the same for the 740, as the diagram shows below.
It's one of the two #16 plugs below:


Here's the air vent routing.


Generally, if I need some quick diagrams and I don't have access to my parts catalogue, I always use www.volvopartswebstore.com

Fa182 said:

On my 940, I routed the cable from the O2 sensor to the passenger side interior through an unused rubber plug right behind the downpipe. It appears it's the same for the 740, as the diagram shows below.
It's one of the two #16 plugs below:

Here's the air vent routing.

Generally, if I need some quick diagrams and I don't have access to my parts catalogue, I always use www.volvopartswebstore.com

Click to expand...

Really appreciate it. So you ran it through the rubber plug. Did you drill a hole or anything into the vent system or just behind the dash and then to the air vent

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I have the V2 vented pod now, but here is one of "aaronllewellyn's" gauge vent pods. I think I still have the V1 pod in the basement here.

I ran my wires with the main harness running across the firewall. There's a large grommet right in front of the driver that has two "nipples" on the top and bottom. I cut and "X" in one of those and ran it through. I had to basically dismantle the vent to get it out, don't pry because it will leave dents in your dash. Run the wire beside the accordion hose feeding the vent and your GTG. Should be the same regardless of whether it's a 7 or 9.

I dont know.. this might work in California.. where it rains and you got a season called autumn you'll need that vent..

89_740Turbo said:

Really appreciate it. So you ran it through the rubber plug. Did you drill a hole or anything into the vent system or just behind the dash and then to the air vent

Click to expand...

I don't have it mounted there. I have it right besides / below the ignition cylinder with a small bracket that I made. It's a bit unconvenient to see but here in Austria, cops will immediately become suspiciuous that I might modified my car to have the need for a gauge like that (it's pretty much illegal to modify anything on your car without having it registered and you won't get approved much...). I just ran the wires behind the heater core and right up to the gauge.

MadDog_945 said:

I dont know.. this might work in California.. where it rains and you got a season called autumn you'll need that vent..

Click to expand...

Yep

MadDog_945 said:

I dont know.. this might work in California.. where it rains and you got a season called autumn you'll need that vent..

Click to expand...

I have the v1 so it has slits on the sides of the pod to allow air pass by it