Found this object sticking out of my firewall today that I've never actually noticed before. (Don't know why) but it appears to be perhaps a valve of some sort, silver in color, with a hex head cap on it, but not exactly sure as I didn't try unscrewing it. ( its just above the air cleaner reset button in the picture) Doesn't appear to be an a/c valve ,just wondering if anyone had a clue what it is or what purpose it serves. Any help would be appreciated. Thanks in advance for your help.
Just a cap for an unused stud GM put on the firewall for some option that was available in the lineup. Never have seen a CNG optioned van in person but I have a feeling the stud held something on it related to it.
1983 G20 Conversion Van, 350 TPI, Reed Hydraulic Roller cam, Ported 906 Vortec, Edelbrock 3817 TPI-Vortec Base, Doug Thorley Tri-Ys, Dual 2 1/2" exhaust, Speed Density 7730 ECM tuned by ME, 700r4 by ME, Stock 1,600 rpm converter, Rebuilt Stock 10 bolt with posi by ME, 3.08 gears, 358 RWHP @ 5,200, 384 RWTQ @ 3,400, 14.66 @ 95.43 w 2.28s 60'
I just wanted to make sure we all knew what we were looking at.
I recognized the cowl as an Express and knew the air filter indicator things were from that era, so I ventured a guess. Unfortunately, I have no idea what that doo-hickey is for.
I have the same thing on my 99 Tahoe. Located on top of the plastic ducting right after it exits the air filter box. Say "Press to Reset". I was looking at the wrong thing, I now see the part in the firewall. Have to look and see if my 99 has that.
Last edited by Meanmachine; May 31st 2021 8:53 am. Reason: sp
On that location on the firewall on my Tahoe, there is some plumbing for the AC coming through the firewall. Does your van have AC or possibly at one time was equipped with it.
GM built these vans ready to go for most options so a lot of them have some redundant parts. For instance my 2002 express has power windows/locks/mirrors, so it also has all the wiring for cruise control, but is not equipped. I suspect if you can find one with the tilt/cruise package but manual windows, it will have some of the wiring for power windows also.
1994 G20 2002 Express, sitting dead 1988 G20 conversion, stored