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willie

Bad short

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Does a bad ground give you a dead short?

As everyone knows I am putting my 72, 454 together. I am getting ready to start it. Before I hooked up batt I put a test light on, between the neg cable and neg side of batt the light came on. So to confine the short I took off the engine side of the fuse panel, it still lights up. So before I take every thing off in the engine bay to see what it could be, does anyone have any ideas? 

Hence the question, if the engine is not grounded right, would it give you a light at the batt?

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Forgot to put in, when I first checked for shorts I went in the car and made sure everything was shut off. That's why I pulled the engine harness from the fuse panel.

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I had a problem like that years ago and after checking all the wires throughout the car several times . It turned out to be a bad negative cable from the battery. Drove me crazy for a week. Bad grounds can cause some strange stuff to happen. Good luck

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Hey Kevin, I am hoping that will NOT happen. lol

After pulling the engine harness out from the fuse panel I went through every wire and plug in the engine compartment. Of course I started with the wires close to the batt and worked my way to the other side of the motor, taking off 1 wire or plug at a time, and then back to the batt to see if the short was still there. The horn relay was last other than underneath the car, I should be happy.

This is the wire that is causing it,

IMG_1129.JPG.2a391a0e3272d1de03502ca62b88ec43.JPG

This orange wire, is where the problem is. As you can see it goes to the horn relay, but where does it come from?  It circles into the harness under the stud of the horn relay. But it is not the same color on the other end of the harness. It also is a fuseable link.

Does anyone know where this goes, and what it does?

Should I just change the horn relay?

 

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I just spoke with Willie over the phone.  We spent time tracing some of the wires using the wiring diagrams.  The big issue with this troubleshooting is the color of the wires shown in all of the diagrams are in many cases a different color than the wires in the harness.  Not only Willie's new harness wires but also the parts car he has that he has been using as a reference.  We have determined the harnesses are correct and the diagrams/schematics are wrong.  A couple examples are  orange wires in the harness that go to horn relay are showing as Red in the Wiring diagrams.  Also the diagrams show the wire going to AC compressor is red where the harness wire is green.  This was just a couple issues we found.

The reason wire Willie was removing caused the test light to not illuminate is the main power from the battery coming to the horn relay (This is the main hot (+) wire supplying power for all things that operate without the key on so removing that wire from the horn relay would cause the test light to not illuminate.  

Willie will now remove fuses from the fuse panel to see if the test light will stay off.  If it does he will start reinstalling the fuses until the light comes on and this may help isolate where the problem is.

rob 

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Thanks Rob, I just took out and checked all the fuses to no avail. All fuses are good and the light still comes on. We think it could be the horn relay, so I will get a new one to replace and see what happens. However if any one else a suggestion please let me know. I will not be getting back to the car for a few days, so if I don't get back to you guys I didn't get a chance.IMG_1134.JPG.223da127e7ff39d9fe4789234d90f949.JPG

These are the wires on the horn relay, first wire on you cant see very well but it is orange and it goes to the relay on top of the a/c box, second wire on is the gray wire that twist down to the back side of the engine harness that goes into the cab of the car, third wire on is red wire that goes to the engine harness across the firewall to the starter solenoid, fourth wire on that you can see the best is orange goes through the front light harness but it does not stay orange we think it changes to red and goes to the voltage regulator.    With that said, the regulator is new, but the horn relay is not, but I did order one and will put it in as soon as it comes in.  I will let you all know what happens after that, but if someone can think of anything else please let me know. Thanks

IMG_1129.JPG

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Willie, In one of the text's I sent you I mentioned a possibility of a bad voltage regulator even a new one could be bad right out of the box.  I had a voltage regulator go bad and it created a drain on the battery so even though yours is new you may wan to try another one.  

rob

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Posted (edited)

Hello Everyone, This is where i am at. I don't know why the pics aren't working.  Maybe because my lap top crashed and i am using my desk top. I will get that fixed later.

I found a few problems but still have gremlins. 1st i finally got juice to right side of fuse box, bent tab and a wire not plugged in. I changed 2 fuses because the glass was cracked. Then i traced down to bad high beam switch. Now the head lights and high beams work.

2nd As i traced to the horn relay (that i now changed) doesn't matter, still have same problems. I have a hot wire (orange) that goes from the horn relay as a fuseable  link and then changes to red in the harness that goes to the regulator #3, according to book i think this is correct. But i also have a (gray) wire on the new engine harness that is causing a draw. It goes into the firewall at the left section top right wire, next to the bolt head. I don't know where it goes after that, nothing is (gray) inside. When i disconnect both orange and gray the draw goes out.

Gremlins I have,  The small fuse at the bottom of fuse box left side marked (inst lps) and terminal next to that i have no juice, so no dash lights. Every other space and fuse has juice.  And the draws from the regulator, orange wire and where does the gray wire go to?

Thanks Willie

Edited by willie

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Hey Willie. 

Dumb question, do you have factory style gauges in your dash? I have heard that the amp gauge wire is hot all the time. Maybe??? 

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Hey Tom, I have the round gauges like in the SS's. So what you are saying is the amp gauge might be my draw? Ok something to check for sure. Thanks for the heads up. i will check it out later. Any and all Avenues are gladly accepted. 

Thanks i give it a shot

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Willie, I am referring to the gauges, not idiot lights. Only the gauges, amp specifically, I'm told is hot/live all the time. 

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Thanks Tom, yes its the gauge and i just checked it, and yes it has juice on both terminals, now another problem, the amp gauge needle is pointed straight down instead of straight up. Do you think its the gauge? 

I did notice that when i had the gray wire off the horn relay i didn't get any juice to the headlight switch. Maybe its the headlight switch its original. 

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Willie, as I understand it, you have a light bulb between the positive terminal of the battery and the positive lug on the battery cable. This puts the light bulb in series between the battery and the car.

I'd try this: Put everything back together as it all should be. Connect the battery, first by just lightly touching the lug to the battery terminal, just in case it's an actual heavy short.

After connected to the battery, make sure everything works and no fuses blow. Do the interior lights go out when the doors are closed? Does the clock work? Does the horn blow? Does the engine start and run? Lights work?

Now, leave everything connected for a few days & nights. Did the battery die?

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Paul, Yes except i did it on the neg side.

Its not a heavy short because i had the batt hooked up already.  Hooked up and no fuses blow. Yes the lights aren't all hooked up but some are. When i open the doors the under dash lights come on fine, close the doors they go out fine. Clock works when batt is hooked up. Haven't checked horn yet. Headlights did not work, i changed the high beam switch and now they are fine. But this was all found out just before i was ready to start the car from rebuilding everything. I didn't want to start car and then have all these issues so i am trying to get them done so i can start it. 

I was thinking of hooking up and leaving to see if it would kill the batt but wasn't sure how safe it was. Didn't want to hurt the car or the garage. Maybe i should do this and see. At this point i will try anything.

However there still has to be a problem because i still can't get power to the small fuse on bottom left (inst lps). Dash lights do not work.

Thanks guys

 

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That small fuse is post rheostat in the light switch. When you pull the switch, it sends power to the rheostat then back to the fuse box, through the small fuse then to all the dash lights on a gray wire. When the lights are off, the fuse is dead.

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Paul, so i should check to see if i have power to that little fuse after i pull the light switch out?

I am starting to look like Telly Savalus, If that's true and it works "Who Loves you Baby" lol I will check tomorrow and get back to you.

Thanks

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Yes but depending on where the knob is turned to, you may not see full voltage. The rheostat varies the voltage.

 

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Hey Paul, i checked that small fuse and i am not getting anything, no matter where i move the headlight switch after pulling it out to turn headlights on. Do you think it could be the headlight switch?

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The dash back lights get their power from the headlight feed through the headlight switch. It's the dark green wire that exits the switch, goes into the fuse box, through the small fuse then exits on the gray wire to all the lights. If the system isn't working, you could start at the dark green wire/terminal on the headlight switch.

Whether this system is working or not, it can't be causing the "dead short" you started this thread with. How is that going?

Headlight Switch 1.jpg

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Hey Paul, i will check that out tomorrow. 

As far as the short, i still have a draw from the gray wire that goes into the back of the fuse box. I thought maybe the headlight switch might be bad. I will look at it again tomorrow.

If i still cant figure it out like you suggested i will leave the batt hooked up and see if goes dead in a few days

Thanks

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Well Willie, as it turns out, except for one short jumper between switches in the AC control panel, there's only one gray wire in the entire car. This is the feed from the small fuse to all the dash bulbs. This wire is spliced and also feeds the lamps in the AC control and radio.

Let's be sure of our terminology, a "short" is where power is connected to ground (-) and either pops a fuse, fuseable link or circuit breaker or it smokes and melts wire(s).

A circuit that simply doesn't work/have power is open or disconnected and not a short.

Where in LI are you?

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Hey Paul, I see you are talking about a wire (gray) under the dash that is spliced, i don't think this is where the draw is from. 

I agree that i am not that good with electric and my terminology is probably not correct as i can put batt terminal on without a very severe spark, but it does spark, and no it does't cause a fuse to blow. Thats why i call it a draw sometimes, as opposed to a short when i first started this post. There were a few electrical problems when i started some have been fixed, and we are working on this one now. I wish it was only one problem and everything would be solved. lol  I am trying to load pics lets see if they work.

This is a pic of the headlight switch plug, it has power on the white, red, and yellow wires.

IMG_1225.JPG.2a9fe2b73f6e5d9ad955c098021c1bdc.JPG

The gray wire that i am talking about, is the gray wire that is hooked up to the horn relay and goes down into the bulkhead (back of the fuse box). This is the wire i think it is. 

IMG_1223.JPG.c5a86cd7a09afb59217440e5cc97d341.JPG

It is next to the mounting bolt on the top left side. These are new harnesses, so i am not 100% sure colors are what they are supposed to be.

I am on exit 62 off LIE

Thanks for your help

IMG_1222.JPG

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Hey Paul on my first pic, it shows power on white, red, and yellow on my plug.  On your pic it shows white a ground, do you think that is the problem?  I also just double checked and yes all three colors have power all the time. I also jumped the yellow and green and got dash lights and the little fuse has power. Should i change the headlight switch?

Thanks

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It's so helpful when GM wiring doesn't match what's in GM's wiring diagrams :doh:

I would say if you jumped two terminals and the dash lights worked, the headlight switch is bad.

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Looking at your last two photos, I'm wondering if your car has replacement (aftermarket) wiring harnesses.

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