Register or Log In To remove these advertisements. |
|
|
|
Thread Tools | Display Modes |
|
06-18-2020, 12:40 AM | #1 |
Registered User
Join Date: Aug 2007
Location: Birmingham, AL
Posts: 41
|
1970 C10 wiring harness question
This truck looks like it retains most of the factory wiring. My question refers to the harness on the driver side in the engine bay, up through the bulkhead/firewall(behind the fuse block).The alternator has a large-gauge red wire coming off the back of it, which goes down to the frame and back up and meets with some other groups of wires right behind the driverside headlight. There is another large gauge red wire that seems to travel with it into the cab(rightside connector on the firewall at the top right wire). Someone cut that red wire to send it to the a/m Sunpro ammeter. I removed the fuse panel inside the cab, and found that red wire along with 2 other large gauge red wires are crimped down to 2 wires(and it looks like a factory crimp).https://ibb.co/MNL2Qkx
My question is, has anyone dealt with these wires before or know what wire they cut in the engine bay for the ammeter?https://ibb.co/w7qxMb8 Just want to be sure I can snip off the a/m ammeter wire and be fine, as I ordered some new gauges with a voltmeter(I dont need any fires in the truck) Thanks in advance Jeff Last edited by koolkat; 06-18-2020 at 07:40 AM. Reason: less to read |
06-18-2020, 10:59 AM | #2 |
Registered User
Join Date: Dec 2017
Location: Elkhart, Texas
Posts: 1,531
|
Re: Wiring question in a 1970 C10
Who knows after all these years and POs, what modifications have been made to the electrical system.. That red wire you described is the main power distribution wire.. It's also part of the charging system.. It goes to the battery, alternator, voltage regulator, ignition switch and fuse box.. Generally speaking, an after market ammeter of the type you describe is installed in series (not shunted) in that wire.. The wire is cut and the gauge is connected to each end of it.. More than likely, you can simply remove the ammeter and splice the 2 wires back together.. The best tool you can have when doing any electrical repairs or modifications is a proper wiring diagram.. You can find those diagrams in the ELECTRICAL forum on this site.
|
06-18-2020, 04:08 PM | #3 |
Msgt USAF Ret
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,703
|
Re: Wiring question in a 1970 C10
__________________
VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative. Last edited by VetteVet; 06-21-2020 at 09:10 AM. Reason: re-entered link |
06-21-2020, 01:58 AM | #4 |
Post Whore
Join Date: Feb 2016
Location: Portland Oregon
Posts: 10,804
|
Re: Wiring question in a 1970 C10
This link describes how those full load style amp meters work and why they can be a problem. The article refers to Dodge trucks but theory is the same. (GM discontinued that style amp meters in the early 60's) Unfortunately for you unless you pull all of the wire loom tape apart and verify what was done you may be driving on a time bomb of sorts.
I believe Rustypile is correct in that you should be able to remove the old amp meter and connect the 2 leads together and everything should work. I however wouldn't be able to stop wondering if everything the PO did was copacetic and never going to fail. Just my opinion. http://www.madelectrical.com/electri...p-gauges.shtml Here is a second link about Chevy wiring. The article is based on earlier car wiring and the actual wiring in our trucks is somewhat different. Like the horn relay is under the dash and not tied in directly to the main charge circuit. But it is close enough if you compare the article with our wiring diagram it will make sense. http://www.madelectrical.com/electri...evymain1.shtml
__________________
Thanks to Bob and Jeanie and everyone else at Superior Performance for all their great help. RIP Bob Parks. 1967 Burban the WMB,1991 S(stink)-10 Blazer,1969 GTO, 1970 Javelin, 1952 F2 Ford 4X4, 29 Model A, 72 Firebird. 85 Alfa Romeo If it breaks I didn't want it in the first place The WMB repair thread http://67-72chevytrucks.com/vboard/s...d.php?t=698377 |
06-21-2020, 09:12 AM | #5 |
Msgt USAF Ret
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 8,703
|
Re: Wiring question in a 1970 C10
Try the link again. It works for me and I re-entered it .
__________________
VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative. |
06-30-2020, 08:34 PM | #6 |
Old member
Join Date: Jan 2002
Location: Liberty, & Garden City S.C. , U.S.
Posts: 19,936
|
Re: Wiring question in a 1970 C10
This should be how it's wired from the factory. All the red wires run together at some point. Most times the junction place is right behind the drivers head light. It's just a crimp connection that is wrapped in tape inside the bundle of wires. Don't worry about the drawing it for adding a newer alternator but the wiring shows the correct junction.
__________________
1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. |
06-30-2020, 09:34 PM | #7 |
Senior Member
Join Date: Apr 2016
Location: Cypress, TX
Posts: 3,563
|
Re: Wiring question in a 1970 C10
That's not the factory wiring, that is my modification of it when installing a 12SI internally-regulated alternator with another junction block.
The stock config: Here's the whole diagram. http://67-72chevytrucks.com/vboard/s...49#post7809749 |
07-01-2020, 04:21 PM | #8 |
Old member
Join Date: Jan 2002
Location: Liberty, & Garden City S.C. , U.S.
Posts: 19,936
|
Re: Wiring question in a 1970 C10
You didn't read my post did you. I stated it was for a newer alternator but the junction is the same.
__________________
1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver Seeing the USA in a 71 Upstate SC GM Truck Club 2013,14 and 2016 Hot Rod Pour Tour http://upstategmtrucks.com/ Get out and drive the truck this summer and have some fun! It sucks not being able to hear! LWB trucks rule, if you don't think so measure your SWB! After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs. |
07-01-2020, 04:41 PM | #9 |
Senior Member
Join Date: Apr 2016
Location: Cypress, TX
Posts: 3,563
|
Re: Wiring question in a 1970 C10
Yes, I saw it and I'm saying the junction is not the same. In my updated diagram you show, there is an additional junction compared to the factory wiring. The factory setup does not have both of these junctions (indicated by the green arrows). Factory wiring just has the one junction with the big black dot where the red wires meet with the ammeter black/white wire.
|
07-02-2020, 12:16 PM | #10 |
Registered User
Join Date: Apr 2010
Location: So Cal
Posts: 1,413
|
Re: Wiring question in a 1970 C10
The under dash splice you also ask about is shown in this image and it is factory. There should be a total of five wires tied together so they may have done it in two spices.
The 12R power feed from the bulkhead connector feeds the Horn Relay, Ignition Switch, Light Switch, and part of the Fuse Box. These connections will be Hot at all times. That junction is center, left in the image. You should be able to use your browser to expand that area of the image to see it in more detail. I could have shown a close up of the splice, but i wanted to show the light switch and ignition switch.
__________________
'67 GMC 2500, 292, 4spd, AC |
Bookmarks |
|
|