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Topic: Shorts

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Shorts (1/25)
 9/7/12 8:41pm
Mynewold75vette
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San Antonio, TX - USA

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So i have figured out that i now have probably a few shorts in my system.  if i leave my battery hooked up for 3 hours with the key off it will kill the battery, and now when i turn the key the starter is completely unresponsive.  i just bought a volt reader and plan on digging into this issue tomorrow, but i've never looked for, located, or even fixed a short in a car before, so any advice as to where to start and how to proceed would be great!  oh and i have downloaded those great wiring diagrams for my year, i just cant make heads or tails of them yet!  

Thanks!


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I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
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Re: Shorts (2/25)
 9/7/12 10:31pm
rod7515Lifetime Member
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Red Lion, PA - USA

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Jon,
Years ago I found this post that has some great troubleshooting techniques that may help you. I have pasted it at the lower side of this reply. I cant take credit for it but I hope it helps you out. Its not from our forum but its a very good post. And it has pictures!
Best of Luck
Rodney



http://forums.corvetteforum.com/c3-general/1737334-battery-drain-test-easy-to-do-with-pics.html

(created live link-aapple)


|UPDATED|9/7/2012 7:31:35 PM (AZT)|/UPDATED|


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Re: Shorts (3/25)
 9/8/12 9:44am
Mynewold75vette
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San Antonio, TX - USA

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well i just did that test where i connect the tester to the negeative end of the battery and the other part of it to the end of the battery cable, with everything off i have a HUGE power drain... also i have noticed that i have a grounding cable near the front passanger side that is connected to the frame and nothing else, the only place i can see it really connecting too would be the starter, but looking at wiring diagrams there should only be 3 wires coming off the starer and i have them all there.  i've included a pic of the hanging ground

Thanks again!


______________

I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
Re: Shorts (4/25)
 9/8/12 11:29am
Mynewold75vette
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San Antonio, TX - USA

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Update:  found the source of the power draw, it was the radio some previous owner hack wired in.  And as far as the starter doing nothing when i turn the key i am begining to suspect that it may be in the key ignition itself... but i have no idea how to remove it, i know the starter is hot but it does nothing when i turn the key, and it is a new starter.

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I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
Re: Shorts (5/25)
 9/8/12 12:35pm
JohnRR
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That big wire coming off the frame in front should connect to your engine block.  Mine is connected to the bolt that holds the forward starter support bracket to the block.  A lot of guys remove this little bracket.  Be sure you have a clean, unpainted surface to connect to. 
You know how the negative battery cable comes off the battery and immediately connects to the frame.  Well, this wire completes that high amperage circuit to your starter.

John


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Re: Shorts (6/25)
 9/8/12 1:52pm
Mynewold75vette
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I'll have to get a longer wire to connect it to that bolt.  I have also looked at some other posts and tested both the small wires going to the starter and the one that runs to the ignition switch is getting no power at all.... i believe the switch is located on the topside of the steering wheel jacket, but i can't see the switch or how to remove it...

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I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
Re: Shorts (7/25)
 9/8/12 3:16pm
JohnRR
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Your starter circuit may be dead because the clutch or neutral safety switch is not closing.  Do you have an Automatic or a 4-speed?  The 4-speed clutch switch is under the dash on the clutch peddle.  I don't know where the Automatic trans neutral switch is.

John


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Re: Shorts (8/25)
 9/9/12 9:13am
yostusota
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The ignition switch is at the bottom of the steering column..neutral safety switch is something to look at also..that big wire needs hooked up..it can be anywhere on the motor..even the mount bolts for the starter..if you are missing power the fusable links at the starter may be burned but get that main ground on before you look for to much..do the obvious stuff first..has this car ever run for you? Need to get a feel for where you are in this project.

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Re: Shorts (9/25)
 9/9/12 11:09am
Mynewold75vette
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San Antonio, TX - USA

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Little on the rough side right now, with new paint and new interior it will be looking fine!


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I got the new ground on this morning and yesterday switched out that ignition switch, i still can't get the starter to do anything while turning the key, and i'm still waiting for the new NSS to get to the parts store.

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I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
Re: Shorts (10/25)
 9/9/12 11:13am
yostusota
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The NSS can be bypassed with a paperclip..just make sure it's un neutral before you hit the key.

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Re: Shorts (11/25)
 9/9/12 9:15pm
Mynewold75vette
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Little on the rough side right now, with new paint and new interior it will be looking fine!


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even if i had a paper clip handy (strange i don't since i became a paper pusher) i don't know where to connect it to bypass the NSS, i'll probably just do body work untill the new NSS gets in and PRAY that it will fix the problem, otherwise i have no idea what i will do....  :(

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I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
Re: Shorts (12/25)
 9/9/12 9:35pm
yostusota
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York, PA - USA

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Ok..paperclip is one of the most useful tools to have with old cars..can fix a whole bunch of stuff with them..except a fuse!! All you have to do is unplug the NSS and put the paperclip in the connection ..it's really that simple..it's just a ground so no worries of a spark.

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Re: Shorts (13/25)
 9/10/12 2:54pm
Mynewold75vette
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San Antonio, TX - USA

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Okay so i tried the paperclip idea, and it did nothing for one of the two connections i put it to and tried, the other one instantly heated the paperclip glowing red when i turned the key, there is a third connection on the old NSS but i can't see anywhere that it would connect to... and i still can't get any life out of the starter...

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I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
Re: Shorts (14/25)
 9/10/12 3:08pm
yostusota
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York, PA - USA

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Ok..that's good..the one connection that got hot had a load on it that's why it got hot..can you remember where that one was?? If you did the one connection that was for the NSS and it did nothing means the switch is ok..do you have power on the single wire on the starter with the key in the start position? Kinda hard to get to but an alligator clip on a test light will let you know fast..it's only with the key in the start position though..try that and see what you have...I know you said it's a new starter but it's not unheard of to get a bad one.

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Re: Shorts (15/25)
 9/10/12 3:35pm
Mynewold75vette
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San Antonio, TX - USA

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Little on the rough side right now, with new paint and new interior it will be looking fine!


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Which single wire on the start?  and this is my second new starter in a week, i don't think they both could have been bad.  Here is a pic of my NSS (new one gets in tomorrow) 

The red arrow is pointing to the plug that was hot, the yellow arrow is pointing to the plug that did nothing with the paperclip in it, and the blue arrow is pointing to the plug that i can't find the end where it used to go into. 


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I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
Re: Shorts (16/25)
 9/10/12 3:49pm
rraider1
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Your wires should be for Starter Purple to Purple/White for Backup lights Pink/wht to Lt Green
 
You need to be carefull it sounds like you put power streight to grnd for the clip to get hot if you jumpered the right pins for the starter and that clip got hot that would meen thir is a short in the purple wire going to the starter, which would burn out your nuetral safty sw.
 
On the 75 wire diagram it shows near the strter that their is a seat belt reset relay, when you go to the second page it is not their, not sue what that means if it is suppose to be their
Re: Shorts (17/25)
 9/10/12 3:50pm
yostusota
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Ok..is there any way that this switch is not adjusted to neutral? Yeah 2 starters would be rare to have bad..the wire on the solenoid by itself closest to the engine should be the one you need for start power to energize the solenoid..I believe there 2-3 small wires on the opposite side..have to have the NSS in to get that to work so maybe wait until the new one comes..

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Re: Shorts (18/25)
 9/10/12 4:09pm
Mynewold75vette
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San Antonio, TX - USA

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I have tested the small wire on the engine side of the starter and it is getting power when the key is turned...  And what should i do to find the short in the system that would let that paperclip get that hot?

______________

I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
Re: Shorts (19/25)
 9/11/12 9:10am
Adams' AppleLifetime Member
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Ah HA!!! Bob hit on something there....early '75s still had the seatbelt interlock system, which will not let the starter engage unless the seatbelt is fastened. But...it has to be done in sequence. First, you have to sit in the seat, then fasten the seatbelt. If the system is still on the car, it will NOT start unless you follow this protocol.
Give that a try, and see if it works.


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Re: Shorts (20/25)
 9/11/12 10:36am
Mynewold75vette
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Just tried it, didn't work.  That was actually the first time i have ever had the seatbelt on in that car so i'm pretty sure that system was disabled a while ago.

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I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
Re: Shorts (21/25)
 9/11/12 12:39pm
Adams' AppleLifetime Member
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Well...it were worth a shot. Unhappy

In the pic of your NSS, the two purple wires are for the starter. One of those wires comes from the ignition switch, and the other goes down to the inner terminal of the starter solenoid. If you have a multi-meter, check them for voltage with the key turned to "Start"...one of them should have 12v. If not, then your problem lies somewhere between the ignition switch and the NSS. If you do get 12v on one of them, then you can run 12v to the other terminal, and you should hear the solenoid at least click. If it does not click, or crank, then you need to make sure your battery cable is connected to the center terminal of the solenoid. With the 12v battery feed, and 12v on the purple wire, it has to crank. If it does NOT, then you have a starter, or solenoid problem.

Just to clarify, when checking voltage at the NSS, you'll need to be testing the vehicle harness side...not the switch itself. If it is unplugged, you will of course not have any power on any of the wires on the NSS.


|UPDATED|9/11/2012 9:39:49 AM (AZT)|/UPDATED|


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Re: Shorts (22/25)
 9/11/12 4:18pm
rraider1
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I found that the interlock relay is located passenger side engine bay above heater core cover, their was a couple of ways people bypassed the relay.
1 they spliced the lt green wire to the purple wire behind the relay mount
2 was they would open up the relay and soldered the contacts inside
 
To start over if you have a test light I would do it this way
 
chk power at purple white wire at NSS no power back to ign sw
chk power at purple wire at NSS in park position or nuetral position no power NSS bad
chk power at Lt Green wire interlock relay NSS in position from last step no power maybe bulkhead connector or wireing
 if interlock relay was bypassed you should have power at purple wire if no power issue is interlock circuit
 
chk power at starter S terminal closest to engine block if power since starter was changed you would have a grounding problem for engine block to frame to battery
 
here is the interlock diagram
 
Joel please double ck me
Re: Shorts (23/25)
 9/11/12 4:49pm
Mynewold75vette
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Found the problem... after the store sent me the wrong NSS, i cleaned up the old one and put it back on, i then took the starter off and had them test it, it tested good and they recomended checking the fuseable links in the line, after putting the starter back on and checking the one link on the wire going to the engine side of the starter she cranked up just fine... no idea how that was causing the problem...

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I hope to one day be as knowledgeable as most the guys on here... but till then I'll have to just keep asking the questions with the obvious answers....
Re: Shorts (24/25)
 9/12/12 1:09am
tb2k82ceLifetime Member
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Did you ever see the movie Gremlins? 

Shocked  That apparently was your problem Gremlins.  That is it. 

By the way I learned a lot from following this post.  As I'm sure others did.
Re: Shorts (25/25)
 9/12/12 2:47pm
yostusota
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York, PA - USA

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there are a bunch of things to check when cars don't work!  Glad it was just a link.

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My first parade at Carlisle 2010
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