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 > 47 - Current classic GM Trucks > The 1973 - 1987 Chevrolet & GMC Squarebody Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 02-05-2012, 02:34 PM   #1
76Blue_Beast
Registered User
 
Join Date: Dec 2011
Location: Lynnwood/ Millcreek, WA
Posts: 91
Question Weird couple questions

Ive posted before about my wire harness that Ive had to replace. I have finally replaced this with my little brother. Now we have a problem; there is a really long light brown wire that has a little rubber booty the looks almost like the end of some headphones. We have no idea what it is for. Good news being the truck turns over and is getting fuel (replaced old filter), we figure we would check the coil for spark but cant find where it is located! I feel stupid for asking but my chiltons manual doesnt show it either as Ive read through it several times. We figured checking for spark would be the first thing to do. Starter fluid has already been tried too. Any help. I can get a pic if needed as Im at work right now. 76 gmc c25 3/4 350/350 Sierra Grande

Thanks,
Ken
76Blue_Beast is offline   Reply With Quote
Old 02-05-2012, 02:41 PM   #2
J Knight
Registered User
 
J Knight's Avatar
 
Join Date: Jun 2011
Location: Baytown TX
Posts: 2,219
Re: Weird couple questions

The coil is located on top of the distributor cap with hei ignition or if you have points ignition it is on the intake between the distributor and the carb. I hope this is what you needed to know.
Posted via Mobile Device
__________________
John
82 Chevy Silverado 350ci/TH350
J Knight is offline   Reply With Quote
Old 02-05-2012, 02:47 PM   #3
76Blue_Beast
Registered User
 
Join Date: Dec 2011
Location: Lynnwood/ Millcreek, WA
Posts: 91
Re: Weird couple questions

ok I will send my little bro down and have him look. Lol we might have just been super tired last night that we kept over looking it. He said the points might be bad or the coil so Ill start to replace the small things. Do you have any idea what the long brown wire is for on the engine harness?
76Blue_Beast is offline   Reply With Quote
Old 02-05-2012, 03:01 PM   #4
J Knight
Registered User
 
J Knight's Avatar
 
Join Date: Jun 2011
Location: Baytown TX
Posts: 2,219
Re: Weird couple questions

Sorry, I wouldnt know about the brown wire. Post a pic so we can see it.
__________________
John
82 Chevy Silverado 350ci/TH350
J Knight is offline   Reply With Quote
Old 02-05-2012, 03:04 PM   #5
rs72z
Registered User
 
rs72z's Avatar
 
Join Date: Oct 2011
Location: Emory TX
Posts: 900
Re: Weird couple questions

Quote:
Originally Posted by 76Blue_Beast View Post
ok I will send my little bro down and have him look. Lol we might have just been super tired last night that we kept over looking it. He said the points might be bad or the coil so Ill start to replace the small things. Do you have any idea what the long brown wire is for on the engine harness?
Sounds like the wire for the brake warning light on the proportion valve. What year model truck is this? Just seen the year. Should have Hei coil is in the cap.
rs72z is offline   Reply With Quote
Old 02-05-2012, 03:17 PM   #6
76Blue_Beast
Registered User
 
Join Date: Dec 2011
Location: Lynnwood/ Millcreek, WA
Posts: 91
Re: Weird couple questions

The wire comes out on the passenger side of the engine harness. It is long too with a rubber booty on it. Its a 76 Seirra Grande 350/350. It is a brand new harness from American Autowire. Unfortunately they arent open today. It's a couple feet long though. My little bro is going to take a pic and send it to me so I can post it. Im at work lol so give me about 15 min or so and Ill add it to this thread.

Thanks for the responses everyone!
76Blue_Beast is offline   Reply With Quote
Old 02-05-2012, 03:24 PM   #7
rwhit57
Registered User
 
rwhit57's Avatar
 
Join Date: Jan 2011
Location: Tulsa,Okla
Posts: 590
Re: Weird couple questions

That brown wire sounds like the fan wire. If you have an HEI dist you just need the one wire(hot when the key is turned on) to the bat side of the cap.
__________________
"Whoever said money can't buy happiness has obviously never seen a speed shop!
rwhit57 is offline   Reply With Quote
Old 02-05-2012, 03:52 PM   #8
76Blue_Beast
Registered User
 
Join Date: Dec 2011
Location: Lynnwood/ Millcreek, WA
Posts: 91
Re: Weird couple questions

How do you tell if you have an HEI Dist? Sorry for the stupid questions.
76Blue_Beast is offline   Reply With Quote
Old 02-05-2012, 04:13 PM   #9
motornut
78K & 79C Jimmys
 
motornut's Avatar
 
Join Date: Nov 2009
Location: Ottawa Ont CANADA
Posts: 7,901
Re: Weird couple questions

coil in the cap is High Energy Ign
thinking fuel sensor wire

in the jimmy that wire was down the pass side, out from the starter wires,to where the arrow is,thats where the "ear bud"looking thing plugged in
Attached Images
   
__________________
John
1978 GMCJimmy4X4-350/203
1979 GMCJimmy4X2-305/350

Last edited by motornut; 02-05-2012 at 04:28 PM.
motornut is offline   Reply With Quote
Old 02-05-2012, 04:16 PM   #10
76Blue_Beast
Registered User
 
Join Date: Dec 2011
Location: Lynnwood/ Millcreek, WA
Posts: 91
Re: Weird couple questions

So maybe this wire is whats causing me to not be able to start it. It will turn but wont start. Hmmmm ok Im waiting for my brother to send me a pic to my work computer then Ill post. Ok ill check this out tonight and then update you all. Thanks guys.
76Blue_Beast is offline   Reply With Quote
Old 02-05-2012, 04:18 PM   #11
J Knight
Registered User
 
J Knight's Avatar
 
Join Date: Jun 2011
Location: Baytown TX
Posts: 2,219
Re: Weird couple questions

Quote:
Originally Posted by 76Blue_Beast View Post
How do you tell if you have an HEI Dist? Sorry for the stupid questions.
HEI has 8 plug wires and a big square cap on top that is screwed down. Points ign has a small cap with 8 plug wires and one big coil wire in the center going to the external coil.
__________________
John
82 Chevy Silverado 350ci/TH350
J Knight is offline   Reply With Quote
Old 02-05-2012, 04:44 PM   #12
76Blue_Beast
Registered User
 
Join Date: Dec 2011
Location: Lynnwood/ Millcreek, WA
Posts: 91
Re: Weird couple questions

thanks you thank you for all these pointers. I feel like I'm getting to know my truck so well since Ive joined this site! You all are great! I love this site, everyone is so helpful and willing to trouble shoot everything for anyone. Thanks again. When I get hom Ill take a much better educated look now!
76Blue_Beast is offline   Reply With Quote
Old 02-05-2012, 04:50 PM   #13
ozark
Registered User
 
Join Date: Jan 2008
Location: Eureka Springs AR
Posts: 179
Re: Weird couple questions

fuel guage wire
ozark is offline   Reply With Quote
Old 02-05-2012, 05:06 PM   #14
76Blue_Beast
Registered User
 
Join Date: Dec 2011
Location: Lynnwood/ Millcreek, WA
Posts: 91
Re: Weird couple questions

cool thx! I'll get pics up as soon as I revive her from the dead. Then off to the trany shop for a make over lol.
76Blue_Beast is offline   Reply With Quote
Old 02-05-2012, 05:38 PM   #15
motornut
78K & 79C Jimmys
 
motornut's Avatar
 
Join Date: Nov 2009
Location: Ottawa Ont CANADA
Posts: 7,901
Re: Weird couple questions

fuel sender sensor won't affect it starting
but it would let you know when empty,does gas squirt

make sure you have 12vdc at the coil cap clip
got Spark?
fuel?
air?
__________________
John
1978 GMCJimmy4X4-350/203
1979 GMCJimmy4X2-305/350
motornut is offline   Reply With Quote
Old 02-05-2012, 05:48 PM   #16
76Blue_Beast
Registered User
 
Join Date: Dec 2011
Location: Lynnwood/ Millcreek, WA
Posts: 91
Re: Weird couple questions

As soon as I get out of work we are going to check all that out. I know it has fuel because I had to change the filter due to a leaking hose. We were stumped on how to check for spark on an hei which is why we couldnt locat the coil in the first place. But everyone has explaind the differences and all so now we are going to figure out how to check for spark. Where or how would I check for air? My brother said maybe the points went bad. I dont know much about this stuff but he has a better idea. He just lacks computer skills so I research on here with you all! :-)
76Blue_Beast is offline   Reply With Quote
Old 02-14-2012, 03:05 PM   #17
76Blue_Beast
Registered User
 
Join Date: Dec 2011
Location: Lynnwood/ Millcreek, WA
Posts: 91
Re: Weird couple questions

Here is an update of the work I've done on the truck with the harness'
Attached Images
   
76Blue_Beast is offline   Reply With Quote
Old 02-14-2012, 05:32 PM   #18
motornut
78K & 79C Jimmys
 
motornut's Avatar
 
Join Date: Nov 2009
Location: Ottawa Ont CANADA
Posts: 7,901
Re: Weird couple questions

dam hope the cookin pics were before
__________________
John
1978 GMCJimmy4X4-350/203
1979 GMCJimmy4X2-305/350
motornut is offline   Reply With Quote
Old 02-14-2012, 09:40 PM   #19
76Blue_Beast
Registered User
 
Join Date: Dec 2011
Location: Lynnwood/ Millcreek, WA
Posts: 91
Re: Weird couple questions

Two are before and the one is the results from us replacing the harnesses .
Posted via Mobile Device
76Blue_Beast is offline   Reply With Quote
Reply

Bookmarks

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 12:14 AM.


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