The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Electrical

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 06-10-2014, 12:38 AM   #1
KyleSeal
Senior Member
 
KyleSeal's Avatar
 
Join Date: Mar 2014
Location: Toano, VA
Posts: 893
What Is This? (Engine bay, 1970 C10.)

Me and my father are working on a 70 C10 currently and are nowhere near wiring pros, we learn as we go. But this has us stumped.

It's right on the firewall (square looking thing with prongs). We believe the engine is an early-mid 80s model (alternator on other side, choke on other sode, ect).

This truck has factory AC, and factory power steering. (If that helps)

Thanks in advance. Hope you guys can help.

BTW: pic is sideways, flip clockwise to have actual in person view. (New to posting pics)
Attached Images
 
__________________
"Sometimes I do serve as a good bad example. Glad to be of service."

My Build Thread (1967 C10, lowered, EFI, daily truck): http://67-72chevytrucks.com/vboard/s...d.php?t=830809

Last edited by KyleSeal; 06-10-2014 at 12:39 AM. Reason: Fix pic.
KyleSeal is offline   Reply With Quote
Old 06-10-2014, 05:22 AM   #2
Aussie Ol' Blue
Registered User
 
Aussie Ol' Blue's Avatar
 
Join Date: Sep 2013
Location: Sassafras. Victoria. The beautiful Mount Dandenong Ranges
Posts: 234
Re: What Is This? (Engine bay, 1970 C10.)

Can you take a clearer pic using a flash? Its hard to see what we're lookin for.
__________________
CLASSIC 1970 C20 WITH A RUMBLIN' V8. IT'S MY MID-LIFE CRISIS ONLY IT AIN'T A LITTLE RED SPORTS CAR OR A HARLEY!

IF YOU'RE GUNNA SKATE ON THIN ICE, YOU MAY AS WELL TAP DANCE!
Aussie Ol' Blue is offline   Reply With Quote
Old 06-10-2014, 07:18 AM   #3
KyleSeal
Senior Member
 
KyleSeal's Avatar
 
Join Date: Mar 2014
Location: Toano, VA
Posts: 893
Re: What Is This? (Engine bay, 1970 C10.)

Quote:
Originally Posted by Aussie Ol' Blue View Post
Can you take a clearer pic using a flash? Its hard to see what we're lookin for.
No problem.
Attached Images
 
__________________
"Sometimes I do serve as a good bad example. Glad to be of service."

My Build Thread (1967 C10, lowered, EFI, daily truck): http://67-72chevytrucks.com/vboard/s...d.php?t=830809
KyleSeal is offline   Reply With Quote
Old 06-11-2014, 01:14 AM   #4
VetteVet
Msgt USAF Ret

 
VetteVet's Avatar
 
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,719
Re: What Is This? (Engine bay, 1970 C10.)

At first I thought it was a relay for the TCS system ( transmission controlled spark) but that didn't start until 1971 I believe. It also looks like the AC fan relay. Does the AC work in the truck?
__________________
VetteVet

metallic green 67 stepside
74 corvette convertible
1965 Harley sportster
1995 Harley wide glide

Growing old is hell, but it beats the alternative.
VetteVet is offline   Reply With Quote
Old 06-11-2014, 09:56 AM   #5
KyleSeal
Senior Member
 
KyleSeal's Avatar
 
Join Date: Mar 2014
Location: Toano, VA
Posts: 893
Re: What Is This? (Engine bay, 1970 C10.)

Quote:
Originally Posted by VetteVet View Post
At first I thought it was a relay for the TCS system ( transmission controlled spark) but that didn't start until 1971 I believe. It also looks like the AC fan relay. Does the AC work in the truck?
It only works when I push all of the switches to the right. With me and my fathers limited knowledge, we believe the AC compressor is not there.
__________________
"Sometimes I do serve as a good bad example. Glad to be of service."

My Build Thread (1967 C10, lowered, EFI, daily truck): http://67-72chevytrucks.com/vboard/s...d.php?t=830809
KyleSeal is offline   Reply With Quote
Old 06-11-2014, 11:52 AM   #6
kwmech
Senior Member
 
Join Date: Mar 2003
Location: Colfax-California
Posts: 8,641
Re: What Is This? (Engine bay, 1970 C10.)

High speed windshield pressure sensor relay.?



(sorry that's all I got)
kwmech is offline   Reply With Quote
Old 06-23-2014, 02:23 PM   #7
Coley
Registered User
 
Coley's Avatar
 
Join Date: Oct 2011
Location: Victoria, B.C
Posts: 3,794
Re: What Is This? (Engine bay, 1970 C10.)

It appears to be a horn relay....not 100% sure but that is what it looks like. It has been added to that (non-original) position under the hood for some reason.
Check up under your dash above your main fuse panel to see if the original one is still there.
Does your horn work?
Coley
__________________
....for some men, there is experience, skill and effort....for the others...there is visa and UPS LOL
1966 Chevy 1/2 ton (Florida- Red/white)
1972 Chevy 1/2 ton (California- Blue/white)
2005 Chevy Silverado HD2500/Duramax
2000 Dodge Ram 1500

Last edited by Coley; 06-23-2014 at 04:31 PM.
Coley is offline   Reply With Quote
Old 06-23-2014, 07:35 PM   #8
truckdude239
Senior Member
 
truckdude239's Avatar
 
Join Date: Sep 2005
Location: Lewisville, Nc
Posts: 10,238
Re: What Is This? (Engine bay, 1970 C10.)

I had one there on my 71 it wasnt hooked up and wasint in the new harness if i went with out it
__________________
David fuller
Ase Certified Mechanic
Click here to help support our board!!


1971 Chevy c-10 under going a 4.8l LSx swap

Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305

2007 Honda Accord my daily 145kmiles
2002 Honda Accord 4 door With 330k(sisters car)
2005 toyota Avalon 228k( brothers car)
2002 Sububran 5.3 245k
2000 Tahoe 5.3l 378

General manager for Marco's Carwash & lube
truckdude239 is offline   Reply With Quote
Old 06-24-2014, 08:34 AM   #9
68panelman
Registered User
 
68panelman's Avatar
 
Join Date: Jan 2011
Location: Delaware and Long Island, New York
Posts: 3,456
Re: What Is This? (Engine bay, 1970 C10.)

My 1970 Blazer has this. It has no A/C, possibly relay for high idle solenoid?
Attached Images
 
68panelman is offline   Reply With Quote
Old 07-14-2016, 10:52 AM   #10
dflarsen77
Active Member
 
Join Date: Jun 2016
Location: Salida, CA
Posts: 177
Re: What Is This? (Engine bay, 1970 C10.)

Came across this old thread while looking at wiring pictures. I have that thing on my firewall too. And it had me stumped too According to the 1970 factory service manual, it's the relay for the transmission controlled spark system. Mine actually had wires attached and running down to the trans area, although it wasn't plugged in. My truck has factory air too and I had thought it might be something for it, but the manual is pretty clear. Cheers!
dflarsen77 is offline   Reply With Quote
Reply

Bookmarks

Tags
1970, air conditioning, beginner, newbie, what is this

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 10:03 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Copyright 1997-2022 67-72chevytrucks.com