@@@ Help Dead Short @@@
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Joined: Sep 2014
Posts: 64
Likes: 1
From: San Antonio Tx
@@@ Help Dead Short @@@
Hello all Corvettes Help Help Help
I just bought my 1st Corvette at a great price with Electrical problems it is a 1991 model. I was told that I could get good advise here. The guy I bought it from is a Manager at a CARQUEST store. It had been sitting for a year and it shows. First of all how do I know if this Vette is a ZO6 or a basic?
We replaced the Plug wires,Injectors the old ones had rust, the alternator battery and some sensors.
It has a dead short. The Battery holds a charge for 4 days and then it is bone dead. I recharge it again overnight with the Neg cable disconnected at the battery. I hook it up and it is fully charged. It starts and runs good until it goes dead again about 4 days and the process starts all over.
Here is what I have been told to do. Give it a full charge and disconnect the Neg cable from the Battery. Take a test light and disconnect the Neg. cable from the Battery and touch it to one end of the test light and the other to the Neg. Battery Cable. If the light comes on then you have a Dead Short. Does this make sense to ya'll?
Now what should I do? Thanks in advance for the help.
I just bought my 1st Corvette at a great price with Electrical problems it is a 1991 model. I was told that I could get good advise here. The guy I bought it from is a Manager at a CARQUEST store. It had been sitting for a year and it shows. First of all how do I know if this Vette is a ZO6 or a basic?
We replaced the Plug wires,Injectors the old ones had rust, the alternator battery and some sensors.
It has a dead short. The Battery holds a charge for 4 days and then it is bone dead. I recharge it again overnight with the Neg cable disconnected at the battery. I hook it up and it is fully charged. It starts and runs good until it goes dead again about 4 days and the process starts all over.
Here is what I have been told to do. Give it a full charge and disconnect the Neg cable from the Battery. Take a test light and disconnect the Neg. cable from the Battery and touch it to one end of the test light and the other to the Neg. Battery Cable. If the light comes on then you have a Dead Short. Does this make sense to ya'll?
Now what should I do? Thanks in advance for the help.
Racer
Joined: Dec 2012
Posts: 451
Likes: 14
From: Okehampton Devon
If you had a dead short, the full power of the battery would be going straight to earth. It would probably melt the loom and set light to the car! You need to disconnect the positive lead and put a multi-meter set to Amps between the lead and battery. Then you'll see how many amps are being pulled. It must be something that's not wired through the ignition like Interior lights, central locking, or sidelights. Check the instrument panel dimmer (it rotates around the headlight switch. If this is up too far, the interior lights will be on full-time.
I'm no auto-electrician, so I'm sure others cleverer than me will come up with more advice
I'm no auto-electrician, so I'm sure others cleverer than me will come up with more advice
Last edited by maddogwyatt; Feb 14, 2015 at 02:10 PM.
Safety Car
Joined: Aug 2013
Posts: 4,427
Likes: 603
From: Minneapolis Mn
I'm no electrician, but the multimeter seems like a good idea. Hook it up then get a starting draw. Then one at a time pull the fuses till the draw drops, that's the suspect circuit.
Once you figure out which circuits are drawing the current out of the battery then that would be the one to troubleshoot IMO.
Some thoughts, so good luck.
Once you figure out which circuits are drawing the current out of the battery then that would be the one to troubleshoot IMO.
Some thoughts, so good luck.
Safety Car
Joined: Nov 2008
Posts: 4,328
Likes: 15
From: Jacksonville FL
I'm no electrician, but the multimeter seems like a good idea. Hook it up then get a starting draw. Then one at a time pull the fuses till the draw drops, that's the suspect circuit.
Once you figure out which circuits are drawing the current out of the battery then that would be the one to troubleshoot IMO.
Some thoughts, so good luck.
Once you figure out which circuits are drawing the current out of the battery then that would be the one to troubleshoot IMO.
Some thoughts, so good luck.
You hafta narrow down your search. There are MANY things which can continue to draw current after they are supposed to be off. There is NO WAY we can tell you its this or that. Follow the advice here and at least tell us which circuit is problematic.
Common current draw things are light sockets. Window, antennae, seat, and headlight motors. Bad door switches can cause draw. Any number of sockets relays, switches, motors, on and on.
Now do you see why its important to do the investigation work? Electrical isnt hard its just tedious as hell.
Do you have a Factory Service Manual? If not and your planning to keep the car you better get one. It will have the electrical wiring diagrams that will show you what is on each circuit.
Bring some more info and we can help you better.
Good luck!
Race Director
Joined: Apr 2002
Posts: 10,036
Likes: 346
From: Anaheim CA
There are also a bunch of fusible links involved. Most of them connect to the "jumper block" behind the battery. Disconnect the fusible inks one by one and see if the problem goes away.
Thread Starter
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Joined: Sep 2014
Posts: 64
Likes: 1
From: San Antonio Tx
Electrical short help
Hello
Thanks maddogwyatt;
I did check to see if any interior lights were left on by checking them at night and I check it every time now before I start it. There is something going on with my Drivers side headlight. When I turn the headlight switch on the headlights rotate and when they finish the Drivers side light keeps making a sound like some teeth on a gear are stripped for about 30 seconds and you can see the lamp and housing jerking. It does this every time and for the same length of time. I looked at both headlights and there is a orange and black wire plug disconnected on the Drivers side and the passenger light has a 2 prong connection unplugged also. I have Goggled this and nobody else has this problem.
What kind of stereo comes in that year of Corvettes? This one has a Alpine. That is the only thing that is aftermarket.
I will get a Multimeter and check this.
I don't want to take it to a automotive shop because they will run the bill up to $ 1k.
The HELMS factory Shop Manual is about $100 now www.helminc.com I will try all the fuse block tracing.
I need to commit or take a loss.
Thanks all.
Thanks maddogwyatt;
I did check to see if any interior lights were left on by checking them at night and I check it every time now before I start it. There is something going on with my Drivers side headlight. When I turn the headlight switch on the headlights rotate and when they finish the Drivers side light keeps making a sound like some teeth on a gear are stripped for about 30 seconds and you can see the lamp and housing jerking. It does this every time and for the same length of time. I looked at both headlights and there is a orange and black wire plug disconnected on the Drivers side and the passenger light has a 2 prong connection unplugged also. I have Goggled this and nobody else has this problem.
What kind of stereo comes in that year of Corvettes? This one has a Alpine. That is the only thing that is aftermarket.
I will get a Multimeter and check this.
I don't want to take it to a automotive shop because they will run the bill up to $ 1k.
The HELMS factory Shop Manual is about $100 now www.helminc.com I will try all the fuse block tracing.
I need to commit or take a loss.
Thanks all.
Thread Starter
Advanced
Joined: Sep 2014
Posts: 64
Likes: 1
From: San Antonio Tx
Pro
Joined: Nov 2014
Posts: 527
Likes: 23
From: Mishawaka Indiana
Divide and conquer has always been my approach. Use an amp meter as mentioned above and disconnect circuits one at a time. You can narrow your search quickly that way. A manual will help a lot but not really needed if you don't mind putting more time into it.
Last edited by Mishawaka; Feb 15, 2015 at 02:14 AM.
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Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
There is something going on with my Drivers side headlight. When I turn the headlight switch on the headlights rotate and when they finish the Drivers side light keeps making a sound like some teeth on a gear are stripped for about 30 seconds and you can see the lamp and housing jerking.
Melting Slicks
Joined: Nov 2005
Posts: 3,323
Likes: 142
From: Green Valley Arizona
To the original poster: you do not have a Z06...not available in 1991. Besides coupe or 'vert, only other "option" was the ZR1...which I doubt you have.
Good luck fixing the headlight motor...and enjoy your "new" Corvette.
Good luck fixing the headlight motor...and enjoy your "new" Corvette.
Safety Car
Joined: Nov 2008
Posts: 4,328
Likes: 15
From: Jacksonville FL
I think you've found your problem. There are three pellets inside the headlight motor assembly that wear out with time. This is an easy fix, and is a common problem. This problem will run down your battery. Search this forum for "headlights". Note that the '88 - '96 design is different than the '84 - '87's.
Racer
Joined: Dec 2012
Posts: 451
Likes: 14
From: Okehampton Devon
Roy is probly right here. As I stated, most electrical motors on our cars sense torque increases when they hit the stop and will shut off. If your headlight gears/ bushings are shot, it may prevent the motor from shutting down completely. You could check it with a DVM as suggested or you can charge your battery back up, unplug the bad headlight and see if it cranks after your 4 day window.
lead and terminal as before. It will read an amperage, showing that something is drawing current. Then disconnect your dud headlamp, and the reading should drop to virtually zero........if you're right!!
Safety Car
Joined: Sep 2004
Posts: 3,953
Likes: 550
From: Mission Viejo CA
If the bushings/pellets are worn out, the current sensors won't be able to detect that the headlight is closed, so will continue to provide power to the motor, thereby running down your battery.
The disconnected two pin connectors are for the under-hood lights. This is one way to turn these lights off if you want to leave to hood open for an extended time. There are mercury switches in the lights which normally turn them off when you close your hood.
Team Owner
Joined: Feb 2006
Posts: 23,133
Likes: 117
From: San Antonio Texas
Another couple of things you can check are if the light goes out in your center console. I left mine open for a couple of days and it took the battery down. Also the little vanity mirror lights in the sun visors can get left on. I shut my garage door last week late at night and noticed a slight glow from inside the car. There was just a peek of light above the passenger side. The little mirror light was on in the visor.