The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - What's this firewall grommet/brown wire for? Where's the tach hole?

**DeadheadNM** · 08-28-2013, 10:58 PM

Pic below shows what I'm interested in. I didn't have a flashlight with me so couldn't follow the wire all the way but it went along the LH frame rail toward the rear. Fuel sending unit? On a pickup this dimple is used for the tachometer harness grommet. On a K5, which dimple is for the tach hole and which is for an aux battery harness? If anyone has pics to post of an OEM tach harness/aux battery harness at the firewall I'd be grateful. I'm adding both in September. Thanks, Pete

08-28-2013, 10:58 PM	#1
DeadheadNM Carpe manana Join Date: Dec 2010 Location: Eau Claire, WI Posts: 12,297	What's this firewall grommet/brown wire for? Where's the tach hole? Pic below shows what I'm interested in. I didn't have a flashlight with me so couldn't follow the wire all the way but it went along the LH frame rail toward the rear. Fuel sending unit? On a pickup this dimple is used for the tachometer harness grommet. On a K5, which dimple is for the tach hole and which is for an aux battery harness? If anyone has pics to post of an OEM tach harness/aux battery harness at the firewall I'd be grateful. I'm adding both in September. Thanks, Pete Attached Images __________________ 1972 K5 CST Highlander Blazer: http://67-72chevytrucks.com/vboard/s...d.php?t=708547 1972 K20 Cheyenne Super: http://67-72chevytrucks.com/vboard/s...d.php?t=528308 Members met: ORANGBLAZ, 2003 silverado, MikeCofield, BB72CHEVKT, Duncan&Son, Sameyrasmea72, THENEWMEXICAN, HotRod C/10, brianthelion02, Sport/Truck, ryanroo, michael bustamante, Dirt's72, Already Gone, WestButteTruck, 57taskforce, Moreyel, painterljp, AASmedic, SoCoC10, Lumaestas, carbuff382, Chevyland