Ground location plz.

WhiteShadow89158

WhiteShadow89158

Well-known member
Joined
Mar 24, 2009
Messages
45
Location
SoCal, CA
Hey folks, my headlights arnt working (shocker) and i read bad grounds and switches are the main problems. they dont go up and down but thats just because of vacume. i dont have the manual so could someone tell me the location of the headlight ground? Also, off topic but in the storage comp. on the pass. side there seems to what looks like to be two relays, i have the one closest to the battery but the one closets to the door is missing. i'm assuming it's missing because there's a bracket and plug thats unplugged just sitting there. Could someone also tell me what that may be for? my wipers dont work either so when i searched for a solution someone mentioned something about the delay control unit, i think this is what i'm missing. thanks folks for looking.
 
Start with the simple stuff like the headlight bulbs or the fuse at the fuse panel, they may just be burned out. If not that then move on to performing voltage tests either with a Volt meter or a test light, check for voltage at the headlights. Headlight switches do go bad but in a C3 they are no fun to get to. The ground on the headlight switch is to the body of the switch. As far as your off topic unplugged relays are concerned, tell us all what year 'Vette you have and maybe someone will chime in with a response.
It has been my experience that if something in these old cars has been unplugged it is because that circuit had a short in it or the car was modified by a PO and the plug is no longer needed.
 
He has an 81 (profile ;) )

The relays in the back are for the radio antenna (a white one) and something else. Yours will also have an ECM in front of the battery with an ESC (knock control) bolted to it. The wiper control box is on the passenger side. It's a big 2 pc. thing, a plastic case with a board inside that has a big metal bracket on it. Factory held together by fiberglass reinforced tape. The tape craps out after time, the board falls out and shorts on the jack. It's very easy to find the thing has a ton of wires going into it. They are discontinued but you can use an earlier model if you find one. The plug is different and the wire colors are too but you can easily snap off your old connector and rewire it to the new one. The leads are easily traced to where the go on the board to see what goes with which one in respect to your original one. Have a pic somewhere but can't find it.
 
cool thanks guys. when i put a volt meter to the headlights, it's reading 19.5 dc V steady. i should be getting 12V right?
 
DeeVeeEight said:
19.5 volts is high ANYWHERE in a 12 volt system. You should see 12 to 14 volts.
Click to expand...

Correct, 14.7 MAX charge rate outta the alternator with the engine running at say 2000 rpm, just above idle....

if you see anything higher, measure at the alt output stud, heavy RED wire and see what it says....14.7 is IT, no higher....if it is...another thread...

measure at the battery, I be very surprised if it's that high....I can see 15 volts or so, but much if any higher, and you should be into wiring/fusible link fry/blowing ....so just battery voltage there, weak battery at 11.xx, fully charged 12.4 to 12.7 or so....

when cranking, battery should not measure lower than 10.5 volts, anything lower and you got a issue with weak battery, measured at the battery terminals directly...nowhere else....

hopefully this covers some primary issues....

:shocking:
 
WhiteShadow89158 said:
Hey folks, my headlights arnt working (shocker) and i read bad grounds and switches are the main problems. they dont go up and down but thats just because of vacume. i dont have the manual so could someone tell me the location of the headlight ground? Also, off topic but in the storage comp. on the pass. side there seems to what looks like to be two relays, i have the one closest to the battery but the one closets to the door is missing. i'm assuming it's missing because there's a bracket and plug thats unplugged just sitting there. Could someone also tell me what that may be for? my wipers dont work either so when i searched for a solution someone mentioned something about the delay control unit, i think this is what i'm missing. thanks folks for looking.
Click to expand...

I am on the road, but I believe that is the power antennae relay, the wiper delay module, and the alarm relay are all there. ECM is next to the battery.,
 
big2bird said:
WhiteShadow89158 said:
Hey folks, my headlights arnt working (shocker) and i read bad grounds and switches are the main problems. they dont go up and down but thats just because of vacume. i dont have the manual so could someone tell me the location of the headlight ground? Also, off topic but in the storage comp. on the pass. side there seems to what looks like to be two relays, i have the one closest to the battery but the one closets to the door is missing. i'm assuming it's missing because there's a bracket and plug thats unplugged just sitting there. Could someone also tell me what that may be for? my wipers dont work either so when i searched for a solution someone mentioned something about the delay control unit, i think this is what i'm missing. thanks folks for looking.
Click to expand...

I am on the road, but I believe that is the power antennae relay, the wiper delay module, and the alarm relay are all there. ECM is next to the battery.,
Click to expand...

o ok cool, the PO tryed to put in a differnt antenna and the alarm is disconnected so thats probably what i'm missing back there. I think i was getting such a high reading from the power because i took out the battery and had the ground and power connected to a jump box untill i get a new battery.
 
That's some hot jump box!

Your 12 volt system should read 12 volts to 13 volts when the motor is off (alternator not spinning).
Your 12 volt system should read 13 to 14.5 volts with the motor running (alternator is charging the system).

Be careful with that jump battery at 19 volts you are flirting with danger, the voltage is a little too high. Is your volt meter accurate?
 
ya i just bought it last year. i tested it at the battery cables and it reads 12.4 so i'm not sure how its increasing itself at the lights. i'll get back to ya when i get the lights working. i'm sure its nothing a 6 pack couldnt fix :beer:
 
You must log in or register to reply here.
Top