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 10-23-2010, 07:46 PM   #1
DuallyFlatbed
Registered User
 
Join Date: Sep 2010
Location: Sevierville, TN
Posts: 6
Ignition switch wiring

My new to me truck has some electrical fire issues the PO had. I believe it has to do with the ignition job he did.

Heres a pick of how im wired now. The wiring diagram has brown and purple together, which mine does not. This isnt the factory switch so im alittle confused on the locations.

I have (going clockwise) Red on "bat"(yellow collar) , tan and brown on "Acc", pink on "Ign", and (in middle) purple on "St".

The stray frayed wire comming from "Acc" was the "brake warn light", it got incenerated all the way to the fuse box. I did away with the wire completly and said forget the brake light, i'd rather my truck not burn down than risk recreating a fire. So i guess i can ditch the other tan wire on "Acc", its for the brake light too.

Questions....

On the factory diagram, which termanals are which?

Im good ditching my brake light warning setup right? No other systems connected?

What is "St" on my ignition stand for?

I know im missing the resistance wire for the alternator, it wasnt included by the PO. According to the diagram it should go to the purple wire also shouldnt it?





DuallyFlatbed is offline   Reply With Quote
Old 10-23-2010, 11:22 PM   #2
VetteVet
Msgt USAF Ret

 
VetteVet's Avatar
 
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,703
Re: Ignition switch wiring

here is a bigger picture of the factory switch. Your switch is missing some wires and depending on which wires you have on it, it may short to ground. The purple wire is the starter solenoid wire and goes on the ST terminal. No other wire goes there.

The red wire is the power wire from the battery.
The brown wire is the accessory wire
The brown/white is the alternator wire to the external regulator for a gauge dash,not an idiot light dash. On those it goes to the alternator light. It goes with the brown wire not the purple.

The pink wire goes to the firewall block for the ignition coil.
The tan wire is for the brake warning and then to the dash cluster to the warning light
The green wire is from the temperature sender and goes to the dash cluster
The dashed purple wire is the same wire as the other purple and it goes to the neutral start switch for automatic transmission trucks.

There's no reason to do away with the brake warning wires because they are just grounding wires for the light in the dash cluster. Don't connect them to any hot wires on the key switch. The key switch grounds the tan and green wires when it is turned on as a check for the lights in the dash cluster . I will check the diagrams again just to be sure
Attached Images
 
__________________
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 10-24-2010, 12:29 AM   #3
gkesseru
Registered User
 
gkesseru's Avatar
 
Join Date: Dec 2009
Location: California, Maryland
Posts: 544
Re: Ignition switch wiring

Here's a shot of the ignition sw borrowed from American Autowire.
Attached Images
File Type: pdf 92969128 510102 IN 0.1.pdf (89.3 KB, 8313 views)
__________________
72 Fleet (died)
78 Step (sold)
55 Step named Fred (sold)
00 F150
68 Step (named El Scorcho by PO)
Build thread for the new El Scorcho http://67-72chevytrucks.com/vboard/s...d.php?t=392932
gkesseru is offline   Reply With Quote
Old 10-24-2010, 01:37 PM   #4
DuallyFlatbed
Registered User
 
Join Date: Sep 2010
Location: Sevierville, TN
Posts: 6
Re: Ignition switch wiring

Ok, so im wired strait?

Pink to "ign"

Purple to "St"

Red to "bat"

The heavy brown wire, the alt field wire, and the warning lamp wires all go to the same terminal..."Acc"?

And this Acc terminal is just a ground to complete the circuit?

Any guesses y a ground would burn up end to end? I thought it would need voltage to burn up.
DuallyFlatbed is offline   Reply With Quote
Old 10-24-2010, 02:10 PM   #5
VetteVet
Msgt USAF Ret

 
VetteVet's Avatar
 
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,703
Re: Ignition switch wiring

Quote:
Originally Posted by DuallyFlatbed View Post
Ok, so im wired strait? NO! NO! NO!

Pink to "ign"------ YES

Purple to "St"------YES

Red to "bat"-------YES

The heavy brown wire, the alt field wire, and the warning lamp wires all go to the same terminal..."Acc"? ----NO, This terminal is hot with the key on. The brown wire is the hot feed to the fuse panel for the accessories and the alternator wire goes to the external voltage regulator . The brown or tan brake wire is a ground path for the brake light in the dash and if a malfunction occurs in the proportioning valve it will provide a ground path for any hot wire that is connected to it. IOW if it is connected to the ACC terminal and the prop valve grounds it. Guess what happens. Instant short to ground.
All the info that I gave above pertains to the factory stock wiring and not to some Mickey Mouse switch the PO put in.

And this Acc terminal is just a ground to complete the circuit? ----NO I explained that in the paragraph above. IN fact you should confirm that the ACC terminal is hot when the key is switched to on or ACC. The ground check is not capable with this switch. If you leave off the brake wire then you should be able to use it. But it won't function but like the factory switch.

Any guesses y a ground would burn up end to end? I thought it would need voltage to burn up.
The ground would not burn up unless it gets voltage, which is why you cannot connect it to the ACC on the key switch.
As soon as you turn on the key it becomes hot and is a potential short to ground.
__________________
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 10-25-2010, 06:43 PM   #6
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

I also have a ignition wiring issue on a truck I just bought.

To keep things consolidated, I posted here rather than starting a new thread.

I think the ignition switch has something wrong for the previous owner to have it wired this way.
If I take something metal and arc the center post with the post to the right (purple wire), the engine will crank and start.

Pictures help me:


Here is the wiring at the ignition switch:


It appears I need a Purple wire to the center post, and a couple browns to the ACC Post.
But I'm thinking the previous owner left them unconnected because of some electrical issue.

Where should I order a new ignition switch from?
The one the truck has now is just hanging there, so I'll also need the OEM nut that connects the ignition switch to the dash panel.
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035

Last edited by LostMy65; 10-25-2010 at 08:03 PM.
LostMy65 is offline   Reply With Quote
Old 10-25-2010, 11:43 PM   #7
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

All my research shows this as the ignition switch, is this what it should look like?
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-26-2010, 12:21 AM   #8
motornut
78K & 79C Jimmys
 
motornut's Avatar
 
Join Date: Nov 2009
Location: Ottawa Ont CANADA
Posts: 7,901
Re: Ignition switch wiring

Quote:
Originally Posted by LostMy65 View Post
I also have a ignition wiring issue on a truck I just bought.

To keep things consolidated, I posted here rather than starting a new thread.

I think the ignition switch has something wrong for the previous owner to have it wired this way.
If I take something metal and arc the center post with the post to the right (purple wire), the engine will crank and start.

Pictures help me:


Here is the wiring at the ignition switch:


It appears I need a Purple wire to the center post, and a couple browns to the ACC Post.
But I'm thinking the previous owner left them unconnected because of some electrical issue.

Where should I order a new ignition switch from?
The one the truck has now is just hanging there, so I'll also need the OEM nut that connects the ignition switch to the dash panel.
if the relay is on the starter you shouldn't have the second (burntish)wire there.but where does it go?
__________________
John
1978 GMCJimmy4X4-350/203
1979 GMCJimmy4X2-305/350
motornut is offline   Reply With Quote
Old 10-26-2010, 12:39 AM   #9
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

Quote:
Originally Posted by motornut View Post
if the relay is on the starter you shouldn't have the second (burntish)wire there.but where does it go?
I'm really thinking myself and the OP have the wrong switch.

More evidence that this is the correct one:
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-26-2010, 12:47 AM   #10
motornut
78K & 79C Jimmys
 
motornut's Avatar
 
Join Date: Nov 2009
Location: Ottawa Ont CANADA
Posts: 7,901
Re: Ignition switch wiring

any part # on the old one?is the key a gm key?
__________________
John
1978 GMCJimmy4X4-350/203
1979 GMCJimmy4X2-305/350
motornut is offline   Reply With Quote
Old 10-26-2010, 01:00 AM   #11
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

I'll try and check tomorrow morning.
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-26-2010, 02:35 AM   #12
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

This post jives with the 5 prongs on the correct switch:
Quote:
Originally Posted by 66c10lwb View Post
Yes, my relay is on the radiator support by the regulator. Mine also has the Battery, Alternator and Regulator red wires routed through it. Along with the wiring diagram link Ray posted above and this one, http://rmcavoy.freeshell.org/Truck_gauges.html
which I've been using to reference the '66 wiring diagram for tracing everything out. Different from the one in the link Ray provide here are my ignition switch wires:
BAT-Red
ACC-Brown/White
IGN-Pink
GRD -Dark Green
SOL-Purple
I have the ACC-Brown /White, SOL-Purple and GRD -Dark Green left to check out. The ACC-Brown /White being an important one with the "resistance wire" inline. So far everything follows the wiring diagram.
If I ohm out the ACC-Brown/White wire with the resistance wire in it would that help identify if it is in good condition? not sure about that one.
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-26-2010, 02:46 AM   #13
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

This is for the 66:

__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035

Last edited by LostMy65; 10-26-2010 at 06:00 PM.
LostMy65 is offline   Reply With Quote
Old 10-26-2010, 03:44 AM   #14
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

Quote:
Originally Posted by motornut View Post
if the relay is on the starter you shouldn't have the second (burntish)wire there.but where does it go?
I'll check that also.

Thanks
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-26-2010, 05:34 PM   #15
DuallyFlatbed
Registered User
 
Join Date: Sep 2010
Location: Sevierville, TN
Posts: 6
Re: Ignition switch wiring

Ok thanks VetteVet and all u others. My generic switch has only 4 posts while the factory has 5. I dont have any ground terminals on my switch.

But that explains the fire, proportioning valve to hot on "acc". It put voltage to my ground.

Im just gonna leave the ground wires (brake warn and temp light) outta the picture until i get a factory switch. I just need to hook up my alt field wire to "acc" and get that other ground wire off. Thanks again guys.
DuallyFlatbed is offline   Reply With Quote
Old 10-26-2010, 05:45 PM   #16
fixit-p
Registered User
 
fixit-p's Avatar
 
Join Date: Dec 2008
Location: Yay Area CA
Posts: 2,329
Re: Ignition switch wiring

Quote:
Originally Posted by DuallyFlatbed View Post
Ok thanks VetteVet and all u others. My generic switch has only 4 posts while the factory has 5. I dont have any ground terminals on my switch.

But that explains the fire, proportioning valve to hot on "acc". It put voltage to my ground.

Im just gonna leave the ground wires (brake warn and temp light) outta the picture until i get a factory switch. I just need to hook up my alt field wire to "acc" and get that other ground wire off. Thanks again guys.
IMO the ground function of the ignition switch serves an important role, in that it lets you know the brake and temp warning lights are working without that bulb check function the bulbs could be burned out and you wont know it even if your brakes go out you wont have any warning. You could still take advantage of the bulb check wiring with that generic after market switch you'll just have to use a relay to do so. Use the purple wire to trigger the relay (terminal # 86) ground out terminals 85 & 30 and connect the tan and green wires to terminal 87. That way whenever you crank the engine it also energizes the relay and grounds out terminal 87 (bulb check).
__________________
1965 GMC shortwide big window
1969 Chevy C20 long (for now)
2005 Silverado 2500HD Crew Cab


Quote:
Originally posted by:Abraham Lincoln "The trouble with quotes on the Internet is that it is nearly impossible to discern if they are genuine."
fixit-p is offline   Reply With Quote
Old 10-26-2010, 06:03 PM   #17
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

I'm just going to order the correct one.

http://www.lmctruck.com/icatalog/cbe/full.aspx?Page=88
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035

Last edited by LostMy65; 10-26-2010 at 06:21 PM.
LostMy65 is offline   Reply With Quote
Old 10-26-2010, 06:04 PM   #18
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

Here is a related article for the dash lights:
http://rmcavoy.freeshell.org/Truck_gauges.html
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 10-26-2010, 10:16 PM   #19
VetteVet
Msgt USAF Ret

 
VetteVet's Avatar
 
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,703
Re: Ignition switch wiring

Quote:
Originally Posted by LostMy65 View Post
I'm just going to order the correct one.

http://www.lmctruck.com/icatalog/cbe/full.aspx?Page=88
While I think you are correct to use the factory switch, let me point out that you will need the harness plug and terminals and you need to be sure you'll have enough wire to reach the key switch after you convert.
__________________
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 10-27-2010, 05:50 AM   #20
stich626
Account Suspended
 
Join Date: Sep 2010
Location: hingham ma
Posts: 1,721
Re: Ignition switch wiring

good read
stich626 is offline   Reply With Quote
Old 10-28-2010, 10:48 AM   #21
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

Quote:
Originally Posted by motornut View Post
any part # on the old one?is the key a gm key?
I see no part #.
It's not a gm key either.

I decided to order a whole new keyed ignition from LMC.
Posted via Mobile Device
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 11-06-2010, 05:31 PM   #22
LostMy65
But Found Her 25yrs Later!
 
LostMy65's Avatar
 
Join Date: Oct 2010
Location: Oregon City, Oregon
Posts: 10,457
Re: Ignition switch wiring

Quote:
Originally Posted by LostMy65 View Post
All my research shows this as the ignition switch, is this what it should look like?
My new ignition switch arrived this last week, and I wired it yesterday. It has the five prongs like the pic above.

I did this:

BAT-Red
ACC-Brown/White
IGN-Pink
GRD -Dark Green
SOL-Purple

All is good now.
Everything works as should.
Posted via Mobile Device
__________________
I lost my 65 - Found it 25 years later:
http://67-72chevytrucks.com/vboard/s...d.php?t=426650

66 C20 Service Truck:
http://67-72chevytrucks.com/vboard/s...d.php?t=428035
LostMy65 is offline   Reply With Quote
Old 07-29-2011, 05:26 PM   #23
elf w/capital T
Registered User
 
Join Date: Feb 2011
Location: North Carolina
Posts: 994
Re: Ignition switch wiring

Quote:
Originally Posted by VetteVet View Post
The ground would not burn up unless it gets voltage, which is why you cannot connect it to the ACC on the key switch.
As soon as you turn on the key it becomes hot and is a potential short to ground.[/COLOR][/B]
and this is what happened to me, and now im backtracking trying to figure out why, VV your the top dog, you know it all you have answered many of my questions before and thank you!
elf w/capital T is offline   Reply With Quote
Old 03-05-2012, 04:33 PM   #24
DAN66
Registered User
 
DAN66's Avatar
 
Join Date: Feb 2012
Location: Santa Fe, NM
Posts: 92
Re: Ignition switch wiring

Are all these wires the same gauge of wire?
__________________
'66 "Wrong bed" (Long stepper) 350, 4-speed
'66 Shortbed Stepside, 350/TH350

www.instagram.com/d_ray_pinstriping
DAN66 is offline   Reply With Quote
Old 06-07-2012, 06:16 PM   #25
Levman74
Registered User
 
Join Date: Mar 2010
Location: Here,AZ
Posts: 2
Re: Ignition switch wiring

This is so sick, I actually had the exact same issue, same replacement switch with incorrect wires, and got hold of the correct switch, identical to all the pics from the OP, this is amazing, awesome help guys thanks
Levman74 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 02:36 AM.


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