What's this relay? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

CST*TEN in Katy · 08-01-2005, 09:58 AM

Could someone tell me what is the relay mounted on the passenger firewall? The pink (faded red?) wire goes thru the firewall all by itseld to the fusebox to a terminal labeled radio. These two wires with spade terminals do not have a home. I think one of them goes to the tranny backup plug. If memory serves, this pigtail has always dangled loose. I don't believe this to be a block heater, as this is a Texas truck.

blazerparts · 08-01-2005, 10:25 AM

heater fan relay?

Harold Shepard · 08-01-2005, 10:47 AM

TCS- TRANSMISSION Controlled SPARK relay, there might still be a funny looking vaccumn switch mounted to the intake still, with two vac. lines one to it from dist. and one from it to ported vac on the carb. This is a early emission attempt it is supposed to retard spark in high gear to reduce emissions. Most of the time the relay and a wire or two is all that is left. Hope this helps. Harold

CST*TEN in Katy · 08-01-2005, 11:08 AM

Thanks Harold. I tossed the factory manifold years ago and put on an Edelbrock Torker. That would explain the homeless wires and the 5 port vacuum tree I have.

08-01-2005, 09:58 AM	#1
CST*TEN in Katy Registered User Join Date: Jul 2005 Location: Katy, TX Posts: 48	What's this relay? Could someone tell me what is the relay mounted on the passenger firewall? The pink (faded red?) wire goes thru the firewall all by itseld to the fusebox to a terminal labeled radio. These two wires with spade terminals do not have a home. I think one of them goes to the tranny backup plug. If memory serves, this pigtail has always dangled loose. I don't believe this to be a block heater, as this is a Texas truck. Attached Images __________________ 1970 CST-10 owned it 26 years, finally back on the road after a 10 year rest. 1989 Suburban 1971 Sleekcraft 455Olds Berkeley 1992 SC400 pimp ricer

08-01-2005, 10:25 AM	#2
blazerparts No,I DON'T have Tourett's Join Date: Mar 2005 Location: Reno, NV Posts: 556	heater fan relay? __________________ '72 K5 CST 350/350 Daily Driver '69 GMC3500 Camper Special CST Flatbed 396/400 Upgraded to show truck '69 GMC 2500 L6292, 3spd beater

08-01-2005, 11:08 AM	#4
CST*TEN in Katy Registered User Join Date: Jul 2005 Location: Katy, TX Posts: 48	Thanks Harold. I tossed the factory manifold years ago and put on an Edelbrock Torker. That would explain the homeless wires and the 5 port vacuum tree I have. __________________ 1970 CST-10 owned it 26 years, finally back on the road after a 10 year rest. 1989 Suburban 1971 Sleekcraft 455Olds Berkeley 1992 SC400 pimp ricer

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

08-01-2005, 10:47 AM	#3
Harold Shepard Registered User Join Date: May 2004 Location: Canton North Carolina Posts: 466	TCS- TRANSMISSION Controlled SPARK relay, there might still be a funny looking vaccumn switch mounted to the intake still, with two vac. lines one to it from dist. and one from it to ported vac on the carb. This is a early emission attempt it is supposed to retard spark in high gear to reduce emissions. Most of the time the relay and a wire or two is all that is left. Hope this helps. Harold



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.