More wiring trouble.... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**COBALT** · 08-08-2002, 12:05 AM

OK, now this one bothers me. I was checking out the front wiring harness under the hood when I suddenly find two disconnected wires I have never seen: orange and red. I thought, "hmmm....wonder what the hell these are", so I trace the orange. Turns out it runs to the outside connection to the detent solenoid inside my transmission! It's f$%king disconnected! The red one goes to the firewall, and is labled at the fuse box "Cig" I assume is the cigarette lighter.

Both have tube-shaped connectors, and are stuck in some plastic holder that can hold 4 connecters of the same type, and looks like it would plug into a male plug somwhere. Question: where in the compartment would the connect? Somewhere around the firewall? I don't see where it should be connected. It's possible I knocked this loose, but I doubt it. I just simply found it wound around the back of the brake booster.

**COBALT** · 08-08-2002, 01:20 AM

TTT (come on guys I need some help here)

**JIMs70GMC** · 08-08-2002, 05:41 AM

On mine the CIG wire went from the lighter to the fuse panel, did not go into the engine compartment. Could it be someone pulled the wire through the firewall to power something under the hood? I believe the tranny had a TCS hooked up, not sure where it went though. I'll be able to check in about 9 hours when I get home from work.
I fell your pain, I did the same thing a year ago, tracing out all the wires under the hood. It felt good when I identified them all, even hooked the temp gauge up and got the ammetter working. Also attached the yellow wire back to the starter selonoid.

**'68OrangeSunshine** · 08-08-2002, 06:39 AM

That doesn't sound stock. [Orange and Gray are optional underdash courtesy lights]. If you have the factory service manual, the wiring diagrams are laid out. It takes some study to start to make any sense out of their hieroglyphic style, but it helps. The '67 and '68 are very similar, the '71 has a sligtly different format with an extra number designator on each line, not just the guage and color of the earlier pubs. I just did that on my truck -- isolated the lines and ran continuity and ground checks; also reburnished the ground spade lugs and mating surfaces, filed any corrosion of every connector; even shot silicon dielectric stuff into the bulkhead connector contacts before bolting it back. I was able to get my voltage regulator to show "charge" without having to buy a new regulator and then have it burn out in 6 months.

johnnyp · 08-08-2002, 08:53 AM

Don't know if it'll help, but here's the wiring diagrams for 67-72:

bouncytruck · 08-08-2002, 11:57 AM

I have the wiring diagram book at home. Your more than welcome to borrow it but you'll have to cross the lake to come get it. It is the exact same diagrams as on the site johnnyp posted.

**COBALT** · 08-08-2002, 12:10 PM

bouncytruck: I may just do that. I have these diagrams, but I can't seem to figure out where the detent solenoid's power source is coming from. Anyone know where the detent wire is supposed to connect? I thought there was a switch under the dash it connects to?

Also, I wasn't complete when I was talking about the "Cig" or cigarette lighter power. Yes, there is a red wire that runs from the fuse box to the cigarette lighter, but back at the fuse box another red wire piggy-backs this connection, and goes through the firewall using a firewall gromet that looks stock. Then it runs to the plastic 4-prong connection I was talking about.

I'm really worried about the connection to the transmission. I can't seem to see where this circuit is in the diagrams.

**COBALT** · 08-08-2002, 02:54 PM

TTT (SOMEONE must know where these wires connect!)

Sinister · 08-08-2002, 07:29 PM

dude, if it's a detent switch for a th400, it's supposed to go to a switch behind the gas pedal...

dwaite72lnghrn · 08-08-2002, 07:40 PM

Yep what he said. wire on the th400 goes to the long flat slide switch connected to the gas pedal. when you push gas pedal all the way it causes the trans to down shift smoother than dropping the lever to 2nd. As far as the other connector where is it located wrapped around to brake booster also?

Suicide-D · 08-08-2002, 08:35 PM

On my 68 with TH400 i have an orange wire coming from my intake mounted switched for the kickdown that goes down to the tranny. then there is a red wire that goes through a grommet into the firewall not sure of it's final destination. it's an "L" shaped plug that goes into the switch... looks like a heavy duty stoplight switch if I had to describe it. I can take a picture if you need me too...

**COBALT** · 08-08-2002, 09:38 PM

Ok, so the detent wire (orange) goes to a switch under the gas petal from the transmission. Great, I figured it was something like that.

The red wire is right along with it though in the same wierd 4 prong connector. On one end it connects (piggy-backs) the red wire that goes to the cigarette lighter from the fuse block. From there it goes through a gromet in the firewall, and finally hangs loose along with the orange one for the transmission inside the engine compartment. If they're both supposed to stay together does the red wire connect under the gas petal too? The orange one doesn't have power but the red one does because it comes from the fuse block. Could that be how the detent switch gets power?

**oldiron** · 08-08-2002, 10:22 PM

If I remember correctly on my old 69 the kickdown switch was located on the drivers side of the carburator in the back so when you stompped on the gas the throttle plate lever attivated it. Sorry I don't remember where it got its power from. It could have been from the red cigarette light power lead.
I think that the kickdown switch on the gas pedal wasn't until 71. That is when they went from a floor mounted gas pedal to a hanging style gas pedal.

**COBALT** · 08-09-2002, 02:05 AM

Ah sh!t! That's it. When I rebuilt my carb 3 months ago there was a 4 prong switch on the main throttle arm that I remember taking off and thinking "what the hell is this for?", and tossed it. It looked burned out anyway. That's what it was for though I bet 1000 bucks.

Damn it. I'm going to have to find another one, or mock-up a switch. You're right there is no switch under the gas petal. It's floor mounted in my truck.

Suicide-D · 08-09-2002, 08:42 AM

it's out of a chevelle, but might work

http://cgi.ebay.com/ebaymotors/ws/eB...tem=1849192811

**COBALT** · 08-09-2002, 11:36 AM

I appreciate the link, but I think all I need is a new 4prong switch that bolts onto the throttle arm. There's a place local to South Seattle called Carbs Unlimited. They're a small operation, but so far they've come through every time when I needed hard to find parts for my 2bbl Rochester.

Thanks guys. NEVER THROW AWAY PARTS, unless you're damn sure you'll NEVER need it! LOL

08-08-2002, 12:05 AM	#1
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	More wiring trouble.... OK, now this one bothers me. I was checking out the front wiring harness under the hood when I suddenly find two disconnected wires I have never seen: orange and red. I thought, "hmmm....wonder what the hell these are", so I trace the orange. Turns out it runs to the outside connection to the detent solenoid inside my transmission! It's f$%king disconnected! The red one goes to the firewall, and is labled at the fuse box "Cig" I assume is the cigarette lighter. Both have tube-shaped connectors, and are stuck in some plastic holder that can hold 4 connecters of the same type, and looks like it would plug into a male plug somwhere. Question: where in the compartment would the connect? Somewhere around the firewall? I don't see where it should be connected. It's possible I knocked this loose, but I doubt it. I just simply found it wound around the back of the brake booster. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-08-2002, 01:20 AM	#2
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	TTT (come on guys I need some help here) __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-08-2002, 05:41 AM	#3
JIMs70GMC user # 2756 Join Date: Jun 2001 Location: Chesapeake, Virginia Posts: 4,612	On mine the CIG wire went from the lighter to the fuse panel, did not go into the engine compartment. Could it be someone pulled the wire through the firewall to power something under the hood? I believe the tranny had a TCS hooked up, not sure where it went though. I'll be able to check in about 9 hours when I get home from work. I fell your pain, I did the same thing a year ago, tracing out all the wires under the hood. It felt good when I identified them all, even hooked the temp gauge up and got the ammetter working. Also attached the yellow wire back to the starter selonoid. __________________ 1970 K25, 8' stepside bed 350/465/205 44 up front, 60 in the rear 4.10s rolling on 33" Dunlop MTs 1986 K5, 350/465/208 Dana 60/14 bolt from a cucv 36" Super Swampers TSL/SX 1983 K20 w/ CUCV axles, 350/700R4/208 sitting on 37" Goodyears 1986 M1031 6.2 diesel, TH400/NP205 locker in the rear and a LS in the front, all stock for now..... 1986 K30, 350/400/205 dana 60 and 14 bolt. I kept the drivetrain. Body/bad and chassis are gone. 1981 K30, 350/465/205 dana 60 and dually 14 bolt. Has a G80, and a flat bed. Going to replace the flat bed. 1985 K20, 350/400/208 10 bolt and SF 14 bolt. I wonder where I can find some 1 tons. Hmmmmm

08-08-2002, 08:53 AM	#5
johnnyp Keepin' It Stock Join Date: Aug 2001 Location: Grand Island, Nebraska, USA Posts: 554	Don't know if it'll help, but here's the wiring diagrams for 67-72: __________________ 72 Sierra Grande - Maych Forget about "do it right the first time". Do it wrong the first time to learn how, then do it right the second time.

08-08-2002, 11:57 AM	#6
bouncytruck SKINNY TIRES RULE! Join Date: Sep 2001 Location: Bothell, WA Posts: 11,049	I have the wiring diagram book at home. Your more than welcome to borrow it but you'll have to cross the lake to come get it. It is the exact same diagrams as on the site johnnyp posted. __________________ bouncytruck 1972 K5 The Hauler 1994 K1500 Suburban The Daily2010 Kia Soul Wife's Ride2014 Fiat 500L

08-08-2002, 06:39 AM	#4
'68OrangeSunshine Senior Member Join Date: Feb 2002 Location: Tucson, AZ USA Posts: 7,107	That doesn't sound stock. [Orange and Gray are optional underdash courtesy lights]. If you have the factory service manual, the wiring diagrams are laid out. It takes some study to start to make any sense out of their hieroglyphic style, but it helps. The '67 and '68 are very similar, the '71 has a sligtly different format with an extra number designator on each line, not just the guage and color of the earlier pubs. I just did that on my truck -- isolated the lines and ran continuity and ground checks; also reburnished the ground spade lugs and mating surfaces, filed any corrosion of every connector; even shot silicon dielectric stuff into the bulkhead connector contacts before bolting it back. I was able to get my voltage regulator to show "charge" without having to buy a new regulator and then have it burn out in 6 months.

08-08-2002, 12:10 PM	#7
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	bouncytruck: I may just do that. I have these diagrams, but I can't seem to figure out where the detent solenoid's power source is coming from. Anyone know where the detent wire is supposed to connect? I thought there was a switch under the dash it connects to? Also, I wasn't complete when I was talking about the "Cig" or cigarette lighter power. Yes, there is a red wire that runs from the fuse box to the cigarette lighter, but back at the fuse box another red wire piggy-backs this connection, and goes through the firewall using a firewall gromet that looks stock. Then it runs to the plastic 4-prong connection I was talking about. I'm really worried about the connection to the transmission. I can't seem to see where this circuit is in the diagrams. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA. Last edited by COBALT; 08-08-2002 at 12:14 PM.

08-08-2002, 02:54 PM	#8
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	TTT (SOMEONE must know where these wires connect!) __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-08-2002, 07:29 PM	#9
Sinister Between Trucks... Join Date: Mar 2002 Location: Los Angeles, CA. Posts: 3,830	dude, if it's a detent switch for a th400, it's supposed to go to a switch behind the gas pedal... __________________ Beat it to fit, Paint it to match...

08-08-2002, 07:40 PM	#10
dwaite72lnghrn Registered User Join Date: Jun 2002 Location: central pa Posts: 1,525	Yep what he said. wire on the th400 goes to the long flat slide switch connected to the gas pedal. when you push gas pedal all the way it causes the trans to down shift smoother than dropping the lever to 2nd. As far as the other connector where is it located wrapped around to brake booster also? __________________ 72 longhorn c30 502BB/th400/fact air/4.11rear/ custom camper 72 bug(the better half's) under reconstruction 2009 HHR aqua blue 71 GMC k20 350/sm465 2009 Chevy hd3500 6.6 Victory Red crew cab dually Dave & Jeanne

08-08-2002, 08:35 PM	#11
Suicide-D Registered User Join Date: Jan 2001 Location: Katy, TX...but the love of my life resides in Dublin,OH. Posts: 1,408	On my 68 with TH400 i have an orange wire coming from my intake mounted switched for the kickdown that goes down to the tranny. then there is a red wire that goes through a grommet into the firewall not sure of it's final destination. it's an "L" shaped plug that goes into the switch... looks like a heavy duty stoplight switch if I had to describe it. I can take a picture if you need me too... Last edited by Suicide-D; 08-08-2002 at 08:40 PM.

08-08-2002, 09:38 PM	#12
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Ok, so the detent wire (orange) goes to a switch under the gas petal from the transmission. Great, I figured it was something like that. The red wire is right along with it though in the same wierd 4 prong connector. On one end it connects (piggy-backs) the red wire that goes to the cigarette lighter from the fuse block. From there it goes through a gromet in the firewall, and finally hangs loose along with the orange one for the transmission inside the engine compartment. If they're both supposed to stay together does the red wire connect under the gas petal too? The orange one doesn't have power but the red one does because it comes from the fuse block. Could that be how the detent switch gets power? __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-08-2002, 10:22 PM	#13
oldiron Designated Grumpy Old Man Join Date: Oct 2001 Location: arlington, washington usa Posts: 3,092	If I remember correctly on my old 69 the kickdown switch was located on the drivers side of the carburator in the back so when you stompped on the gas the throttle plate lever attivated it. Sorry I don't remember where it got its power from. It could have been from the red cigarette light power lead. I think that the kickdown switch on the gas pedal wasn't until 71. That is when they went from a floor mounted gas pedal to a hanging style gas pedal. __________________ Never let the truth get in the way of a good story 71 Chev 1/2 ton 4X4 LWB Fleetside SOLD http://67-72chevytrucks.com/vboard/s...d.php?t=361222 http://www.youtube.com/watch?v=1LgREwtDfaA 68 Chev 1 ton flat bed http://www.youtube.com/watch?v=0bO8szzlD4A 56 Chev Handyman Wagon http://www.youtube.com/watch?v=9y-6ddpBTkM http://www.youtube.com/watch?v=lbLzZ7zY8wA 56 Chev Belair http://67-72chevytrucks.com/vboard/s...d.php?t=410667 http://www.youtube.com/watch?v=xoW0Ei7ZNIg

08-09-2002, 02:05 AM	#14
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	Ah sh!t! That's it. When I rebuilt my carb 3 months ago there was a 4 prong switch on the main throttle arm that I remember taking off and thinking "what the hell is this for?", and tossed it. It looked burned out anyway. That's what it was for though I bet 1000 bucks. Damn it. I'm going to have to find another one, or mock-up a switch. You're right there is no switch under the gas petal. It's floor mounted in my truck. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

08-09-2002, 08:42 AM	#15
Suicide-D Registered User Join Date: Jan 2001 Location: Katy, TX...but the love of my life resides in Dublin,OH. Posts: 1,408	pedal setup on ebay it's out of a chevelle, but might work http://cgi.ebay.com/ebaymotors/ws/eB...tem=1849192811



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08-09-2002, 11:36 AM	#16
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	I appreciate the link, but I think all I need is a new 4prong switch that bolts onto the throttle arm. There's a place local to South Seattle called Carbs Unlimited. They're a small operation, but so far they've come through every time when I needed hard to find parts for my 2bbl Rochester. Thanks guys. NEVER THROW AWAY PARTS, unless you're damn sure you'll NEVER need it! LOL __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

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