Finally sold myfinally completed 71, picked up a 2005 loaded magnetic red with 57,000. Here is the provblem, parking and tail lights randomly flash as car is sitting in garage. No set time for flash totaly random. When I fist got car horn would not work. Replaced horn mico relay, good now. This light ting one got me stumped. never had these kinds of issue with my 71. Killing battery if it was not for battery tender, which by the way never goes green so far. Any ideas?

71 stockray

 

Might have better luck if moved to appropriate forum. Know that kind of stuff can drive you nuts. Good luck 😎

 

I have a 2005 Magnetic Red coupe also with 35,000 miles. Bought it new in 2004 and have never had this problem. But I had a 1995 Olds Aurora with a similar issue. This may have nothing to do with your cause, but it's a possibility.

That problem was located in the light stalk on the steering column. Lithium (?) grease had oozed into some contacts that was causing intermittent shorts. This caused the lights to flash when parked. Had to disconnect the battery to not drain it. Did some Google searches and found that dealer's would charge hundreds to replace the light switch stalk.

Found another site that showed how to remove the steering column cover and clean the contacts with an electrical contact cleaner. That fixed it. That site provided step-by-step instructions on how to do it, and took me more than an hour. Saved me big bucks.

 

Do you have the fob with you when this happens?

 

Flashing tail lights is normal when you leave the car and move out of the FOB's range. Mine has always done that when I leave the car. It its way of visually saying "I'm locked up." Do you have an owner's manual? You bet, a battery tender should be standard equipment for these cars. Do you have a M6 or automatic? If manual, be sure to park it in reverse gear otherwise the main system does not shut down. Your tender might not go green if the battery is old or failing. I would replace the battery is more than a couple of years old.

 

Here is some info including where grounds are located:

Park, Tail, License and Marker Lamps
Battery voltage is applied at all times from the PK LAMPS fuse to both coil and switched sides of the PARK LAMP Relay located in the underhood fuse block. Ground is applied at G201 to the turn signal/multifunction switch at all times. When the headlamp switch is place in either the HEAD or PARK position, ground is applied to the park lamp relay control circuit. This energizes the PARK LAMP Relay and applies battery voltage to all park, tail, license, and marker lamps. Ground for the front park and marker lamps is supplied at G101 for the left and G102 for the right. Ground for the license, tail, and rear side marker lamps is supplied at G302.

Malfunction
Circuit/System Description
Battery positive voltage is applied at all times from the PARK LAMPS fuse to both the coil and switched sides of the PARK LAMP Relay in the underhood electrical center. Ground is applied from G201 to the multifunction switch at all times. When the headlamp switch is place in either the HEAD or PARK position, ground is applied to the park lamp relay control circuit. This energizes the PARK LAMP Relay and applies battery positive voltage to all of the park, tail, license, marker, and position lamps. For more detailed information concerning park lamp operation refer to Exterior Lighting Systems Description and Operation .

Park, License, and/or Tail Lamps Malfunction
Ignition OFF, disconnect the park lamp relay.
Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal C9 and ground.
⇒ If the test lamp illuminates, test the control circuit for a short to voltage.

Verify that a test lamp illuminates between the B+ circuit terminal A9 and ground.
⇒ If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test the control circuit terminal C9 for a short to ground. If the circuit tests normal, test or replace the park lamp relay.

Verify that a test lamp illuminates between the B+ circuit terminal A8 and ground.
⇒ If the test lamp does not illuminate, test the B+ circuit for an open/high resistance.

Disconnect the harness connector at the inoperative park lamp.
Test for less than 1.0 ohm of resistance between the inoperative park lamp ground circuit and ground
⇒ If greater than the specified range, test the ground circuit for an open/high resistance.

Connect the harness connector at the inoperative park lamp.
Connect a 10A fused jumper wire between the B+ circuit terminal A8 and the control circuit terminal C9. Verify the park lamps are activated.
⇒ If the park lamps do not activate, test the control circuit for an open/high resistance. If the circuit tests normal, test or replace the inoperative park lamp.

Connect a test lamp between the B+ circuit terminal A9 and the control circuit terminal C8.
Command the parks lamps ON and OFF with the park lamp switch. The test lamp should turn ON and OFF when changing between the commanded states.
⇒ If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM.

⇒ If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM.

If all circuits test normal, test or replace the park lamp relay.

 

I suspect Sunnyvale Dave has the answer ... if you have the fob in your pocket, and have auto-lock enabled, the care will lock and unlock as you in and out of range. It will flash the lights (or sound the horn) depending on how you have it set. The C6 is not bad in this regard ... my early (first 1,000 1997s) was awful, but entertaining ....

 

Fob in my pocket or not still does it. I know the lock up flash, what I am getting is a single flash at random times. I clocked it no two light flashes are the same time apart. Though I had it this morning as battery was on charge all nigh, but it just did it 4 times in 15 minutes. Put battery back on charger for another 90 minutes at 2 apms, we will see what happends. battery is still not up to full charge.

 

Still sounds like a weak battery issue to me. These cars do all sorts of odd things with a battery that is not up to the task. How old is the battery and has it ever been run completely down? I would start there before doing anything else.

 

Will the car start? Driving the car should charge the battery fairly quickly.

 

Battery is fully charged at 12.9 still doing it, chevy wants 130 $ an hour to find. Should I just let them, am out of ideas. Disconnected power for one hour today, replaced micro relays on thst circut. Still random flash.