The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - 68 C10 Yellow wire from firewall to starter/coil.

ymi5150? · 10-26-2018, 10:52 AM

jumping on this thread for some help.

a bit of background - my son was gifted his great grandfather's 68 C20. i'm working with him to improve reliability and safety. it has decades of mickey mouse work and neglect that i'm working through. it hasnt run since we took ownership. i have a Holley Sniper as part of the upgrades. before i install, i wanted to get the motor to turn over (not start). we havent been successful so far due to purple wire not getting 12v at ignition turn. the harness was trashed so i bought a new one from LMC.

when i pin the yellow and the purple wires without connecting to the starter, i get the following:

yellow - 12v switched. it reads 12v when key is turned to on position.

purple - nothing

i'm just getting started on troubleshooting. i'm not too worried about the purple lacking power. i need to check the NSS and ignition switch.

my concern is around the yellow wire. my understanding is that it receives 12v starter solenoid is engaged. is that correct? any experience here?

10-26-2018, 10:52 AM	#34
ymi5150? Registered User Join Date: Sep 2018 Location: los gatos, CA Posts: 5	Re: 68 C10 Yellow wire from firewall to starter/coil. jumping on this thread for some help. a bit of background - my son was gifted his great grandfather's 68 C20. i'm working with him to improve reliability and safety. it has decades of mickey mouse work and neglect that i'm working through. it hasnt run since we took ownership. i have a Holley Sniper as part of the upgrades. before i install, i wanted to get the motor to turn over (not start). we havent been successful so far due to purple wire not getting 12v at ignition turn. the harness was trashed so i bought a new one from LMC. when i pin the yellow and the purple wires without connecting to the starter, i get the following: yellow - 12v switched. it reads 12v when key is turned to on position. purple - nothing i'm just getting started on troubleshooting. i'm not too worried about the purple lacking power. i need to check the NSS and ignition switch. my concern is around the yellow wire. my understanding is that it receives 12v starter solenoid is engaged. is that correct? any experience here?