KahnBB6

iTrader: (5)

It is tabbed in exactly as it’s designed and it’s definitely in there correctly. When you install one of these you’ll see that there is only one way they can be installed and seated.

It’s a pretty clever design considering it replaces a very specific part of an internal dash sub-assembly in the only way it can to get in there securely.

I’ll have to take another angle to give you a better idea but the gauge face will protrude outward further than the original vent will. Resting in the car it’s perfectly fine to my eyes FWIW.

The only thing you need to be careful of is the rear depth of some gauges hitting the vent flapper. Probably wires will have the potential to do that too but this is a design tradeoff to gain extra function from the dashboard that Lexus/Toyota never originally intended.

For instance, my Prosport electric boost gauge rests a bit deeper than my VDO voltmeter gauge and the latter works a little better against the internal vent flapper. Jimmymac30 installed a BTI “CAN” gauge in this location and it worked well also (see previous posts for a picture).

Since I haven’t done any wiring yet I can’t comment further on that but no regrets at all about installing this part. I’m happy with it so far.

I may pick up another gauge that has internal LED lighting rather than a traditional bulb the way the VDO gauges do. That way I probably would never have a reason to remove the gauge for service. However once you get the original vent out it is easy to remove whichever aftermarket gauge you choose to.

I recommend turning the flapper dial further and further to closed as you remove a 52mm gauge from the housing to once again create a solid barrier to catch the two removable tabs if they also happen to come out when removing the gauge.

Probably won’t if there is the previously recommended painter’s tape on them already. Even clear packing tape might be a good idea but you want to be able to remove the tape for service to replace it with fresh and new stuff as necessary.

The key will be the sweet spot of having just enough tape wrapping around the barrel of your 52mm gauge so that it is snug but still easily removable if you need to do so.

All the painter’s tape I used is purely internal and not visible once the gauge is installed.

KahnBB6

iTrader: (5)

Welcome, Rudy! I know that initial vent removal was the only major roadblock. I really had no idea I would solve that last night. I just had a little time to fiddle with it again and think about it.

Actually yes I do have a recommendation. The Illumination power wires you want are conveniently located on the OEM cigarette lighter connector at the OEM ashtray.

I already took advantage of those wires when I installed the replacement ashtray gauge panel that Autoextrude also sells.

It’s a little OEM four pin connector right under the ashtray. Blue in color from the factory. I have the part number for the male and female ends of the connector (they will not come in blue any longer if ordered for replacement) as well as the two types of repair terminal spade wires for each side of it. I’ll pull those from my old custom wiring notes to post here.

I used those findings to make a new harness for the whole ashtray panel area.

Now what I will do is revise that harness.

I just remembered I did make a post about this in my build thread with pictures. I’ll have to find it later and post the link.

Basically I suggest running your custom vent gauge harness wires through the dash back to the ashtray location for the +12V Switched, Ground, Illumination wire and you can also run your gauge signal wire(s) there.

This makes even more sense to do if you already have a replacement 2x 52mm gauge panel where the factory ashtray used to be since you will already need to tap into the same wires in that location anyway.

I haven’t gotten to this yet in my car but I will find and suggest a compact OEM-style aftermarket connector that you can use to make a quick disconnect of the vent gauge harness and ashtray wiring for removal of the dash or other servicing.

But of course that will require building/soldering/heat shrink wrapping some custom wiring.

Pictures will help illustrate what I’m describing. I’ll make a follow up post soon to show you what I mean.

The main focus I have with this for the moment is how I want to run the wire bundle for my vent gauge *from* the vent. I just haven’t tried it... yet.

RudysSC

Great response, and good thinking using the power to the cig lighter backlight. I'll be sure to use that when it comes time to install mine fully! I'm thrilled you found an easy method and really look foward to taking advantage of that location for a stealth set up.

KahnBB6

iTrader: (5)

Late coming to this post but yes, that's definitely the best place to tap for the "Illumination" 12V power wire.

I know you've fully installed and wired yours up now Rudy. I'm just getting to mine after waiting for a new gauge to be delivered. I found today that both of my Prosport gauges are the same depth and clear the full motion of the A/C vent flap. However I imagine another 1-1.5" of wire behind those spades will not. I'm going to try making my wiring harness very compact by using 90-degree angled spade connectors to keep the wires pointed either sideways or down. Hopefully they will clear and I can then also retain full range of motion with the A/C flapper

Here's an example of what I'm talking about:

RudysSC

Those will help a great deal I'm sure! My problem wasn't the wiring, but the oddly long fitting for the "boost tube" is what caused me to have to put mine upside down in order to maintain the vents opening/closing function. I need to get creative and re-route some things to be able to mount the gauge correctly.

On a silly side note - I love my black background Autometer gauge with the red bulb cover on it. The light red/pinkish backlight makes me reminiscent of old Blitz gauges and things of the like from back in the day. Plus, it's dim enough that it's hard to see from the outside, but bright enough that it's easily visible while driving. I don't want onlooking WRX's to see my boost gauge before they see my tail lights

KahnBB6

iTrader: (5)

The right angle spade connectors will arrive tomorrow so I'll find out shortly if they are compact enough Next I need to find a decent grommet. I only need four 14ga or 16ga wires with wrapping to pass through a drilled hole in the A/C vent so it doesn't need to be very big but it does need to have a lip on either side of the ABS plastic tunnel.

The Autometer gauge you choose sounds like a classic style indeed! Will you share a picture of it installed?

The pressure tube means that you have a mechanical boost gauge with the pressure metering parts built into it directly. Has to have the pressure hose tap plumbed right into it. This is the reason I searched for a classic style boost gauge that's electric (but with an analog dial) and which only needs the 12V, Ground, Illumination and signal wires run into it. A little external boost sender installed under the hood is what will interpret the boost pressure and convert that into an electrical signal that can be run through one wire all the way into the cabin.

That boost pressure tube extending backward will most certainly hit the A/C duct's flapper plate unfortunately :/

The frustrating thing about looking for analog style electric boost gauges is that there are fewer options to choose from in a classic/traditional style that look very close to factory analog gauges that you'd see in stock 80's/90's European and Japanese cars. But there are a great number available electric boost gauges to choose from if a very broad range of styles are appealing.

Are you still looking for a good place to tap for the boost pressure feed to that gauge? On your stock 2JZ-GTE intake manifold there is a factory location where you can use a three-way tapered screw in splitter part from the Toyota parts bin:

Order Toyota P/N 90413-05002 90917-11027 (Edit: initially listed the incorrect part number).

It allows you to replace this part:





With this part:







The 2JZ-GTE Fuel Pressure Regulator VSV has to be hooked up there. The additional two pressure nipples can be used for the SC300's Heater Control Valve vacuum connection (with in-line filter) and also for a boost pressure hose connection (also requiring an in-line filter).

KahnBB6

iTrader: (5)

Just to share with you all how I made the compact wiring harness for my gauge.

As Rudy mentioned above there is a problem with any very deep protrusions at the top of any gauge hitting the A/C vent flapper when it’s in the full open position.

Rudy temporarily solved this issue by installing his mechanical boost gauge upside down so that the rubber/silicone pressure line were at the bottom and thus wouldn’t conflict with the vent flapper.

For me this same problem came from my VDO Vision Black gauge’s traditional backlight bulb holder sticking out quite deeply into the upper end of the duct cavity. As such... I had the same issue.

I solved this with a couple of changes:

1) I bought a new gauge that has built in LED backlighting.

For me, a Prosport 52mm. Although the gauge barrel itself is slightly longer than the VDO gauge’s barrel depth that it replaced, there are only spade ends after that and nothing else protruding further backward.

I purchased a Prosport voltmeter gauge and Prosport electric boost gauge. Both are internally LED backlit, have the same barrel depth and the same spade connectors at their rear.

2) I used those spade-end “Flag” connectors that I posted about previously. They bend at 90 degrees and thus allow a little harness to be made with is mostly flat against the rear of the 52mm gauge.

This provided the necessary clearance required to still allow full travel of the A/C duct flapper just behind the gauge. This should work for all in most cases.




Crimping these flag connectors is a bit of a pain but they work well.

To feed the harness through:

I temporarily inserted the Autoextrude vent pod without the little tabs and noted where there would be just the right spot at the bottom of the duct AFTER the vent pod to drill a pilot hole at a slight angle (but centered).

I then found a drill bit that was slightly bigger than the thickness of my self-made four wire gauge harness and kept stepping up gradual sizes larger until I could finally drill with the final bit diameter that I needed.

I disconnected the harness from the gauge, fed the harness wires through that drilled hole and got them snaked under the dash as I liked and fed them to the radio area where the needed 12V Switched, Ground and Illumination wires are located at the ashtray/cigarette lighter connector.

Back to the gauge pod, I then installed the pod, *flipped the duct flapper down to block anything dropped from getting lost in there*, and inserted the two tabs oriented at the correct sides and pointed in the right direction (there is only one correct way to install them so make sure you’re left with a smooth area for the gauge to go in).

A bit of blue painter’s tape went onto each tab to gently them in place, and then the 52mm gauge was wrapped with blue painter’s tape to give it just a little more tension/thickness when inserted.

I connected the gauge harness wires and started pulling on the harness from the bottom to get the gauge closer to the pod (you will need the corner interior trim pad just below the side vent removed for this).

I had to pull on the vent pod gently while simultaneously pushing the gauge into it. It takes some fiddling but this works and it was in.

I kept adjusting the slack of the harness out of the vent duct itself and left a little slack on it inside the dash cavity.

Under the dash I zip tied it in a couple of places and coiled the excess up in the stereo area for hookup later on.

And that’s it!

If you pick an LED backlit 52mm electric-type gauge of almost any kind and use flag connectors to make your gauge wiring harness it should be a very clean install.

Electric-type can be a digital or analog gauge. You just want any gauge that uses an electric sender so as to keep its hookups very compact and simple in the duct.

....

Also, at the SC's OEM center console ashtray with the flip-lid, if you are already planning to add a gauge panel there as well (one of Autoextrude's or another design) you can have a very easy plug and play custom made harness for both it and your side A/C gauge pod with the following OEM Toyota/Lexus connector:

P/N 90980-10794

The same connector from the factory on the ashtray assembly is blue. A new one from Toyota will be white. You can also request the matching repair terminal wires to go with it. There are four of them and they should be in quite sufficient gauge sizing for accessory connections just like the stock wires in the original ashtray assembly. One of the four wires is also for the interior illumination lights and makes a perfect tap for the backlights on all your gauges.

An example of the original blue connector that has in this picture been removed from the original ashtray assembly and grafted into a custom gauge panel + 12V DC port harness.