Temp sender unit -- which is which? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

MarcMyWord · 10-25-2004, 01:28 PM

I have a '70 pickup with the original 250 cid and 3-speed manual trans. I recently had to take the head off and have since forgotten where a few of the wires attach.

My head has two temp sending units. One is on the water inlet housing, and the other is about mid-way along the head on the drivers side. If my research is correct, the one unit is for the idiot light (my truck does not have gages), and the other is part of the TCS loop. Problem is, I can't remember which is which.

Also, more out of curiosity sake rather than any needed functionality, does anyone have schematics (vacuum and electrical) of the TCS emmisions system? As with most trucks this age, mine has long been bypassed but all the components are still in-pace.

Thanks,

Marc (MarcMyWord@aol.com)

68w/sbc406 · 10-25-2004, 03:18 PM

on my 68 when it had an inline i only had the one to the head, it was an idiot light. then i changed it for a temp gague and i put it back in the head.

Longhorn Man · 10-25-2004, 10:49 PM

welcome to the board from central ohio...where you at?

Are you actually going to hook up the TCS stuff? From what I hear about it, it was a poor primitive set up that wasn't worth the time.

MarcMyWord · 10-26-2004, 08:49 AM

Hello! I live outside of Philadelphia...this is my Home Depot run truck, and not a restoration project. But the truck does look decent and after a valve job and new exhaust, it runs pretty damn good too.

I'm not looking to get the TCS system running again, but as an engineer, it bugged the crap of me not knowing what all those disconnected wires and plugged vacuum solenoids did!! At least I have an understanding of the system now.

I need to know which temp sender runs the indicator light so I can ensure that feature is still operational.

Thanks for the help!

-Marc

stelth2002 · 10-26-2004, 11:13 AM

The one in the head goes to the idiot light.

10-25-2004, 01:28 PM	#1
MarcMyWord Registered User Join Date: Oct 2004 Posts: 7	Temp sender unit -- which is which? I have a '70 pickup with the original 250 cid and 3-speed manual trans. I recently had to take the head off and have since forgotten where a few of the wires attach. My head has two temp sending units. One is on the water inlet housing, and the other is about mid-way along the head on the drivers side. If my research is correct, the one unit is for the idiot light (my truck does not have gages), and the other is part of the TCS loop. Problem is, I can't remember which is which. Also, more out of curiosity sake rather than any needed functionality, does anyone have schematics (vacuum and electrical) of the TCS emmisions system? As with most trucks this age, mine has long been bypassed but all the components are still in-pace. Thanks, Marc (MarcMyWord@aol.com)

10-25-2004, 03:18 PM	#2
68w/sbc406 Got Light Emitting Diode? Join Date: Apr 2004 Location: Newberg, OR Posts: 2,485	on my 68 when it had an inline i only had the one to the head, it was an idiot light. then i changed it for a temp gague and i put it back in the head. __________________ 1968 1/2 ton 2wd lwb 6 lug disc and bags up front. Next c notch and rear bags '02 Chevy Silverado LT ext cab short bed 2WD 5/7 drop on 22's(the family car) 1993 Cherokee work ride/weekend wheeler

10-26-2004, 11:13 AM	#5
stelth2002 Young Gun wth Fast Inline Join Date: Jan 2002 Location: Idaho Posts: 1,475	The one in the head goes to the idiot light. __________________ 1967 Chevrolet LWB with built 292! 415 ft. lbs of torque, 4 speed :O with 27% overdrive too, 3.73 Posi. Frame and body done... getting painted!!!

10-25-2004, 10:49 PM	#3
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	welcome to the board from central ohio...where you at? Are you actually going to hook up the TCS stuff? From what I hear about it, it was a poor primitive set up that wasn't worth the time.

10-26-2004, 08:49 AM	#4
MarcMyWord Registered User Join Date: Oct 2004 Posts: 7	Hello! I live outside of Philadelphia...this is my Home Depot run truck, and not a restoration project. But the truck does look decent and after a valve job and new exhaust, it runs pretty damn good too. I'm not looking to get the TCS system running again, but as an engineer, it bugged the crap of me not knowing what all those disconnected wires and plugged vacuum solenoids did!! At least I have an understanding of the system now. I need to know which temp sender runs the indicator light so I can ensure that feature is still operational. Thanks for the help! -Marc



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