1968 GMC C2500 4 spd V8 - Page 2 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

ProStreet83C10 · 10-01-2007, 11:17 PM

update on wiring..............its a MESS

i crawled under the truck tonight and theres open wires simply twisted together, played with thosse a bit and got RH tail and turn to work, no RH brake and LH is inop. at this point, bulb is good. Checked fuse for brake/tail and it is good as well.

Only working gauge is oil press. speedo, volts, fuel gauge and water temp do not work. If nothing else i need fuel gauge and speedo to work. Rest will more than likely get replaced by aftermarket gauges. May plan on doing full autometer gauge cluster in future.

I will try and get some pics of the wiring so you guys know what nightmare i just brought myself into. Plan on working on it all day after work Wed.

67_C-30 · 10-26-2007, 11:31 PM

Don't hate me, but you look just like the dude in the Goody's Commercial!
Nice rig, though!

Bucky71 · 10-27-2007, 09:01 AM

Cool truck. What's this?

68K20 x Drill · 10-02-2007, 03:11 AM

That is an interesting back bumper, looks like it could make quite an impression.

caminokid · 10-10-2007, 11:54 AM

Quote:

Originally Posted by 68K20 x Drill

That is an interesting back bumper, looks like it could make quite an impression.

I have that same back bumper! It rusted all to you know where. I am changing mine out this weekend.

I didnt think I would ever see one of those again.

earl87gta · 10-02-2007, 03:32 AM

Speedo is machanical sounds like the cable is broke time to spend the $12 bucks for a new one. the rest of the gages are elcetrical so how bad is the wireing under the dash hacked up. you may be better off finding a under dash harness from some one on the board or buying a new one. The boody looks to be in good shape you have a great project there.I cant remeber how the fuela sending wiring was ranin the trucks but its possible it broke some were I would folow it back from the tank to the dash and see if it is cut some were.

**Yukon Jack** · 10-02-2007, 11:06 AM

I hate tracking down electrical issues! Good luck on that project. On both of my trucks I went ahead and went with new wiring harnesses for the engine compartment - mine were so brittle on the K5 that I knew it was a wise decision plus they aren't too expensive. The under dash new harness is unfortunately pretty expensive. Hopefully you can find a simple problem or just replace with a good used harness. Not a bad idea to splice in a new 4 wire line from the firewall to the rear lights - they get pretty bad from rubbing on the frame.

The truck has lots of potential after you get through the initial problems.

ProStreet83C10 · 10-02-2007, 01:37 PM

thanks guys and yeah it does.,....runs awesome now that i got a lot of the old fuel out. I also hate wiring/electrical games with vehicles. Im just glad it doesnt have a nice big wiring thing like new cadillacs and high end cars with all the little toys.

earl87gta · 10-03-2007, 03:21 AM

Good to here its running good. It’s nice not having a lot of wiring to it. Sent you a PM.

ProStreet83C10 · 10-04-2007, 12:09 AM

got the PM thanks, will see what i can do with wiring before i buy a new harness....if you find a good one keep it for me just in case....

earl87gta · 10-04-2007, 12:27 AM

did you get the speedo working you should be able to replace the cable with out taking the dash or any thing apart. they usaly strip out on the transmition side of the cable.

ProStreet83C10 · 10-04-2007, 11:24 PM

havent gotten that far yet.....replaced valve cover gaskets tonight and worked on rear lighting wiring.

Also need to replace something in the shifter because we are able to like pull the shifter out of the transmission and thats not right at all.

1987_3/4ton_chevy · 10-10-2007, 09:21 AM

We got the shifter to stay in the transmission last night. Also, any ideas what to do with the back tail lights? We re-wired it from the hood on back to the lights.... what else should we look for?

earl87gta · 10-10-2007, 12:28 PM

It has to be in the wiring from the fuse block to the switch. I cant remeber but does the switch has seprate inputs for the tail lights if it does to could change it. I would start witht he fuse block theck the tail light fuse it may be a rusted socket you may have to clean it up some. seams like I remeber my 67 having that trouble once and all I did was sandpapered the fuseblock conection.

1987_3/4ton_chevy · 10-10-2007, 01:16 PM

thanks dude, i will check that when i get time to look that over.... thanks

earl87gta · 10-10-2007, 05:41 PM

Any time I hope it helps

1987_3/4ton_chevy · 10-10-2007, 08:07 PM

what do you mean by that?

earl87gta · 10-11-2007, 12:44 AM

I just hope I’m not sending you on a wild goose chase and have you later find out it was a bad ground or something.

1987_3/4ton_chevy · 10-11-2007, 11:59 AM

oh i see, its ok i am bring down my truck i think to the central IA BBQ thing on a trailor so you know... more people can pin point the problem i think and hope. thats my plan atless is to bring it down

1987_3/4ton_chevy · 10-12-2007, 11:09 PM

Well guys, we started taking off the paint and almost one whole side is completed!! Pictures will be posted soon.... keep you all updated!

1987_3/4ton_chevy · 10-26-2007, 10:22 PM

Well my duddy stopped over and helped scrape the paint off and almost the whole right side is done.... getting closer but need more money lol.

streetstar · 10-27-2007, 12:19 AM

that looks "rust free" for an Iowa truck --- cool deal Lucille

dave3156 · 10-27-2007, 08:20 AM

Looks like a great truck to work on. the speedometer problem could be the plastic gear in the transmission. These are notorious for breaking, might want to check it before you just replace the cable. They are pretty easy to replace too. Good luck and have fun!

1987_3/4ton_chevy · 10-27-2007, 12:44 PM

First off, thats not me in the photo... my friend was being a Smart A**

1987_3/4ton_chevy · 10-27-2007, 12:45 PM

Whats what?

10-01-2007, 11:17 PM	#1
ProStreet83C10 Drag Racer Join Date: Nov 2006 Location: Mason City, Iowa Posts: 1,276	Re: 1968 GMC C2500 4 spd V8 update on wiring..............its a MESS i crawled under the truck tonight and theres open wires simply twisted together, played with thosse a bit and got RH tail and turn to work, no RH brake and LH is inop. at this point, bulb is good. Checked fuse for brake/tail and it is good as well. Only working gauge is oil press. speedo, volts, fuel gauge and water temp do not work. If nothing else i need fuel gauge and speedo to work. Rest will more than likely get replaced by aftermarket gauges. May plan on doing full autometer gauge cluster in future. I will try and get some pics of the wiring so you guys know what nightmare i just brought myself into. Plan on working on it all day after work Wed. __________________ Zach Hall 1983 Chevy C10 R/T: .194 60': 2.322 330: 6.379 1/8: 9.803 MPH: 71.37 1000: 12.781 1/4: 15.314 MPH: 88.79

10-26-2007, 11:31 PM	#2
67_C-30 I have a radical idea! Join Date: Jan 2005 Location: Sweet Home Alabama! Posts: 6,513	Re: 1968 GMC C2500 4 spd V8 Don't hate me, but you look just like the dude in the Goody's Commercial! Nice rig, though! Attached Images __________________ '67 C-30 Dually Pickup 6.2 Turbo Diesel, NP435 ‘72 C-10 SWB , 350 4bbl, TH350 '69 C-10 SWB , 250 L6, 3 OTT '69 GMC C3500, dump truck, 351 V6, NP435 '84 M1009 CUCV Military Blazer 67 C-30 Turbodiesel build thread http://67-72chevytrucks.com/vboard/s...d.php?t=254096 My trucks http://s226.photobucket.com/albums/d...ediafilter=all Member of the 1-Ton Club!

10-27-2007, 09:01 AM	#3
Bucky71 Registered User Join Date: Jul 2007 Location: Toronto, On Posts: 65	Re: 1968 GMC C2500 4 spd V8 Cool truck. What's this? Attached Images

10-02-2007, 03:11 AM	#4
68K20 x Drill Registered User Join Date: Apr 2007 Location: Freedom CA Posts: 488	Re: 1968 GMC C2500 4 spd V8 That is an interesting back bumper, looks like it could make quite an impression. __________________ 68 Chevrolet k20 Longbed 350 SM465/205, Dana 44, 14bolt, Power steering, Power Disk Brakes, 35" BFGs. 84 Chevrolet Suburban K20 6.2 Banks turbo TH400/NP208 Now with G80 68 GMC C20 Parts? Truck And a few cars

10-02-2007, 03:32 AM	#6
earl87gta Senior Member Join Date: Dec 2003 Location: Kingsport TN Posts: 4,641	Re: 1968 GMC C2500 4 spd V8 Speedo is machanical sounds like the cable is broke time to spend the $12 bucks for a new one. the rest of the gages are elcetrical so how bad is the wireing under the dash hacked up. you may be better off finding a under dash harness from some one on the board or buying a new one. The boody looks to be in good shape you have a great project there.I cant remeber how the fuela sending wiring was ranin the trucks but its possible it broke some were I would folow it back from the tank to the dash and see if it is cut some were. __________________ Earl 68 2500 4x4 GMC Burb Last edited by earl87gta; 10-02-2007 at 03:34 AM.

10-02-2007, 11:06 AM	#7
Yukon Jack Post Whore Join Date: Feb 2000 Location: Rose Hill, KS, USA Posts: 12,684	Re: 1968 GMC C2500 4 spd V8 I hate tracking down electrical issues! Good luck on that project. On both of my trucks I went ahead and went with new wiring harnesses for the engine compartment - mine were so brittle on the K5 that I knew it was a wise decision plus they aren't too expensive. The under dash new harness is unfortunately pretty expensive. Hopefully you can find a simple problem or just replace with a good used harness. Not a bad idea to splice in a new 4 wire line from the firewall to the rear lights - they get pretty bad from rubbing on the frame. The truck has lots of potential after you get through the initial problems. __________________ 1970 Blazer with a 400 sbc and 4" lift 1980 Pontiac Trans Am, 455 Oldsmobile 2012 Kawasaki Concours 14

10-02-2007, 01:37 PM	#8
ProStreet83C10 Drag Racer Join Date: Nov 2006 Location: Mason City, Iowa Posts: 1,276	Re: 1968 GMC C2500 4 spd V8 thanks guys and yeah it does.,....runs awesome now that i got a lot of the old fuel out. I also hate wiring/electrical games with vehicles. Im just glad it doesnt have a nice big wiring thing like new cadillacs and high end cars with all the little toys. __________________ Zach Hall 1983 Chevy C10 R/T: .194 60': 2.322 330: 6.379 1/8: 9.803 MPH: 71.37 1000: 12.781 1/4: 15.314 MPH: 88.79

10-03-2007, 03:21 AM	#9
earl87gta Senior Member Join Date: Dec 2003 Location: Kingsport TN Posts: 4,641	Re: 1968 GMC C2500 4 spd V8 Good to here its running good. It’s nice not having a lot of wiring to it. Sent you a PM. __________________ Earl 68 2500 4x4 GMC Burb

10-04-2007, 12:09 AM	#10
ProStreet83C10 Drag Racer Join Date: Nov 2006 Location: Mason City, Iowa Posts: 1,276	Re: 1968 GMC C2500 4 spd V8 got the PM thanks, will see what i can do with wiring before i buy a new harness....if you find a good one keep it for me just in case.... __________________ Zach Hall 1983 Chevy C10 R/T: .194 60': 2.322 330: 6.379 1/8: 9.803 MPH: 71.37 1000: 12.781 1/4: 15.314 MPH: 88.79

10-04-2007, 12:27 AM	#11
earl87gta Senior Member Join Date: Dec 2003 Location: Kingsport TN Posts: 4,641	Re: 1968 GMC C2500 4 spd V8 did you get the speedo working you should be able to replace the cable with out taking the dash or any thing apart. they usaly strip out on the transmition side of the cable. __________________ Earl 68 2500 4x4 GMC Burb

10-04-2007, 11:24 PM	#12
ProStreet83C10 Drag Racer Join Date: Nov 2006 Location: Mason City, Iowa Posts: 1,276	Re: 1968 GMC C2500 4 spd V8 havent gotten that far yet.....replaced valve cover gaskets tonight and worked on rear lighting wiring. Also need to replace something in the shifter because we are able to like pull the shifter out of the transmission and thats not right at all. __________________ Zach Hall 1983 Chevy C10 R/T: .194 60': 2.322 330: 6.379 1/8: 9.803 MPH: 71.37 1000: 12.781 1/4: 15.314 MPH: 88.79

10-10-2007, 09:21 AM	#13
1987_3/4ton_chevy Cowboy Up Join Date: Jun 2007 Location: Mason City, Iowa Posts: 203	Re: 1968 GMC C2500 4 spd V8 We got the shifter to stay in the transmission last night. Also, any ideas what to do with the back tail lights? We re-wired it from the hood on back to the lights.... what else should we look for? __________________ 1971 chevy k10 Under the Knife Chris Cary

10-10-2007, 12:28 PM	#14
earl87gta Senior Member Join Date: Dec 2003 Location: Kingsport TN Posts: 4,641	Re: 1968 GMC C2500 4 spd V8 It has to be in the wiring from the fuse block to the switch. I cant remeber but does the switch has seprate inputs for the tail lights if it does to could change it. I would start witht he fuse block theck the tail light fuse it may be a rusted socket you may have to clean it up some. seams like I remeber my 67 having that trouble once and all I did was sandpapered the fuseblock conection. __________________ Earl 68 2500 4x4 GMC Burb

10-10-2007, 01:16 PM	#15
1987_3/4ton_chevy Cowboy Up Join Date: Jun 2007 Location: Mason City, Iowa Posts: 203	Re: 1968 GMC C2500 4 spd V8 thanks dude, i will check that when i get time to look that over.... thanks __________________ 1971 chevy k10 Under the Knife Chris Cary

10-10-2007, 05:41 PM	#16
earl87gta Senior Member Join Date: Dec 2003 Location: Kingsport TN Posts: 4,641	Re: 1968 GMC C2500 4 spd V8 Any time I hope it helps __________________ Earl 68 2500 4x4 GMC Burb



Register or Log In To remove these advertisements.

10-10-2007, 08:07 PM	#17
1987_3/4ton_chevy Cowboy Up Join Date: Jun 2007 Location: Mason City, Iowa Posts: 203	Re: 1968 GMC C2500 4 spd V8 what do you mean by that? __________________ 1971 chevy k10 Under the Knife Chris Cary

10-11-2007, 12:44 AM	#18
earl87gta Senior Member Join Date: Dec 2003 Location: Kingsport TN Posts: 4,641	Re: 1968 GMC C2500 4 spd V8 I just hope I’m not sending you on a wild goose chase and have you later find out it was a bad ground or something. __________________ Earl 68 2500 4x4 GMC Burb

10-11-2007, 11:59 AM	#19
1987_3/4ton_chevy Cowboy Up Join Date: Jun 2007 Location: Mason City, Iowa Posts: 203	Re: 1968 GMC C2500 4 spd V8 oh i see, its ok i am bring down my truck i think to the central IA BBQ thing on a trailor so you know... more people can pin point the problem i think and hope. thats my plan atless is to bring it down __________________ 1971 chevy k10 Under the Knife Chris Cary

10-12-2007, 11:09 PM	#20
1987_3/4ton_chevy Cowboy Up Join Date: Jun 2007 Location: Mason City, Iowa Posts: 203	Re: 1968 GMC C2500 4 spd V8 Well guys, we started taking off the paint and almost one whole side is completed!! Pictures will be posted soon.... keep you all updated! __________________ 1971 chevy k10 Under the Knife Chris Cary

10-26-2007, 10:22 PM	#21
1987_3/4ton_chevy Cowboy Up Join Date: Jun 2007 Location: Mason City, Iowa Posts: 203	Re: 1968 GMC C2500 4 spd V8 Well my duddy stopped over and helped scrape the paint off and almost the whole right side is done.... getting closer but need more money lol. __________________ 1971 chevy k10 Under the Knife Chris Cary

10-27-2007, 12:19 AM	#22
streetstar Registered User Join Date: May 2007 Location: Moore, Oklahoma Posts: 2,396	Re: 1968 GMC C2500 4 spd V8 that looks "rust free" for an Iowa truck --- cool deal Lucille

10-27-2007, 08:20 AM	#23
dave3156 Registered User Join Date: Mar 2004 Location: St. Louis, MO Posts: 336	Re: 1968 GMC C2500 4 spd V8 Looks like a great truck to work on. the speedometer problem could be the plastic gear in the transmission. These are notorious for breaking, might want to check it before you just replace the cable. They are pretty easy to replace too. Good luck and have fun! Last edited by dave3156; 10-27-2007 at 08:21 AM.

10-27-2007, 12:44 PM	#24
1987_3/4ton_chevy Cowboy Up Join Date: Jun 2007 Location: Mason City, Iowa Posts: 203	Re: 1968 GMC C2500 4 spd V8 First off, thats not me in the photo... my friend was being a Smart A** __________________ 1971 chevy k10 Under the Knife Chris Cary

10-27-2007, 12:45 PM	#25
1987_3/4ton_chevy Cowboy Up Join Date: Jun 2007 Location: Mason City, Iowa Posts: 203	Re: 1968 GMC C2500 4 spd V8 Whats what? __________________ 1971 chevy k10 Under the Knife Chris Cary

Register or Log In To remove these advertisements.