VETTE N ME

Hello all!! My Clock/Lighter/Courtesy fuse blows immediately when I put a new one in. I took the center gauges out, I took the speedo cluster out, I disconnected the lighter. It still blows. In my owner's manual it says that this fuse controls the clock, lighter, courtesy, anti-theft alarm, glove box, and dome. I checked the under dash lights and the dome light and things look fine. My interior is completely out of the car including carpet so I am trying to get this done before i put the under carpet insulation in. All help is appreciated!! Thanks in advance!!

mtnance

Sounds like you need to trace some wires. Something is grounding or touching another wire. Wish I could wave a wand but this might be tedious to do.

martinsw

Get an ohm meter (most voltmeter have an ohm setting) to measure the resistance from the fuse wire to ground. Try to unhook everything connected (remove/disconnect clock, lighter, dome bulb, courtesy light, glove box light and anti-theft module).

If resistance still low you need to trace the wires and physically find the short. If resistance is high with everything off, put them back one at a time to find the bad device.

A light bulb might draw say 1 amp, that means a nominal resistance of 12 ohms. Shorts typically read near zero ohms.

0Willcox Corvette

Did you check the dome light timer? If not, unplug it and see if the problem goes away.

Early 78


Late 78-82

VETTE N ME

Unplugged it still happens

VETTE N ME

Could it be within the anti-theft system. My door locks are not in my doors. Is there wires inside the doors?

0Willcox Corvette

Nope..

I think if you go over this list you'll find your wire.. I traced the entire orange wire circuit tonight to see if I could figure it out... Have you looked at the spare tire lamp.

Here are the items (unless I missed one and if i did, someone feel free to post in).

LH COURTESY LAMP
RH COURTESY LAMP
Glove box lamp
Dome lamp
Spare tire lamp
Anti Theft Relay
Anti theft horn engine compartment.
courtesy lamp timer.
Clock

Good luck.. there is a 1981 timer circuit trace on my web site you can up load under Repair and install help.. it might help you but it's way different than the 78.

Jet Tech

On my 79 you can add:

Power Door Locks
Power Antenna

VETTE N ME

This was laying inside my driver's door just laying there.

speedreed8

car alarm, anti theft protector switch and control arming switch. goes on the key door lock.
http://www.corvetteforum.net/c3/tune.../index24.shtml

doorgunner

Like Willcox said....Also......There was a recall on the storage light that I read about. Techs accidentally connected the two wires to the light in "reverse",,,,the ground went to the bulb positive contact/the 12vpositive was connected to the socket ground terminal/eventually something would cause a direct short that never blew the fuse because of the long run of wire....which explains why that sub-harness in my '68 car was fried from the light almost to the dash.

Please keep your battery disconnected until you find the short.

HBZ_81_C3

Rodney, Check the glove box light. Make sure the screw that holds the light cover on the right side hasn't been installed threading its way through the wires for the light.

VETTE N ME

Hey John. I don't see my glove box light but I see the switch for it

HBZ_81_C3

There are six screws that hold the glove box into the dash. 2 upper, 2 lower and 1 on each side. On the right side, the screw also has a small metal plate that is the cover for the light bulb and socket. If you pull the glove box out you will see what I'm talking about. Check the wires for the light to see if the glove box screw has been threaded through them.

VETTE N ME

I do not see a light. Does the bulb fit in back of the switch itself? My interior was already all apart when I bought the car.

HBZ_81_C3

Yes

VETTE N ME

Well I got a set of test leads and hook them up to the fuse slot and then to a 12volt light. The light came on and I then started unplugging things that looked suspect. I unplugged this and the light went off!!

NOW I NEED TO KNOW WHAT RELAY IS THIS? THE FUSE NO LONGER BLOWS, SO COULD THIS RELAY BE THE PROBLEM?

VETTE N ME

It's the power antenna relay. Are these problematic or could there be a short somewhere after the relay?

Jet Tech

At the relay, try disconnected the the other plug (it goes out to the antenna) and reconnecting the plug that you have removed.

For reference, if you do need to remove the antenna itself, the connector on my 79 is accessed by removing the left rear speaker.

For further reference, to test the antenna on my 79:
Antenna up = Green +, Grey -
Antenna down = Green -, White +

VETTE N ME

Well when I disconnected the other plug fuse was good. Plugged it back in an it popped the fuse. The antenna itself was unplugged. So there is a short in the wiring after the relay.