cls241

I picked up a 2001 C5 6-speed today and drove it home from WA State. Good thing I got home before dark, as now that's it's dark I can't get the headlights to come on, I can't get dash lights to come on. If I turn the car off, the dash lights come on then, but if I start the car it goes dark again. I read about turning Twilight Off by going into options / twilight-ON / Reset, but hitting reset does not change it too off. The friend who I purchased it from said it had some issues with twilight, but if just turned the car off and back on the headlights would open. Nothing, nothing opening and I can't see the dash in the dark with the car on. I am out of ideas outside of taking it into a shop.

Does anyone have any ideas?

No matter what setting, when I turn the car on in the DARK, no headlights

No Dash lights when car is running

Dash Lights come on when I turn off the car until I exit and then turn off on their own in about 30-seconds.

yellow2007

Step 1 is rotate that little **** below the HUD controls. That's the interior/dash light dimmer. Step 2 is disconnect the negative battery terminal for about 30 minutes then retry. Many electrical gremlins can be fixed by this. Then start with the fuses. Mini fuses 3&4 in the underhood fuse box are for the headlight motors....3=right,4=left

cls241

Thanks
I have not disconnected the negative battery terminal. Once it warms up (it's 39 outside), I will try that in a bit. Let it sit for half an hour or more.

The fuse confuses me, since the dash lights come on when I turn the car off, they stay on while the door is open and then about 30-seconds after the door is closed/locked, so if the fuse is out, I would expect no dash lights, right?

I tried the **** (yesterday) - it pops out (dimmer control) left for low light, right for higher lights, and then to the right, and it turns on (click) cabin lights. The click for cabin lights works, but it does not cause any lights to come on the dash.

Maybe the negative terminal will resolve the reason I can't change any of the options like turning off Twilight to see if I can turn the headlights on manually. I can circle through "options" but I can't make any changes, none of the other buttons seem to do anything at this point.

I will try the battery / negative in a while and see if that works, thanks. If any other ideas pop up, please let me know, it's appreciated. I am calling local shops since I may have to take it in if I can't resolve.

Stormjr58

I have a Generational 2000 automatic convertible that has been doing the same thing for a while now.
I don't have tail lights either. I do have brake lights and turn signals that work correct.

Totally agree with your thoughts about the battery.
IF the lights come on when you shut the key off they have power right????

so something Related or more confusing???????
Not sure that the mix of electrical Gremlins are the same at all....but,
I installed the LMC5 module today to eliminate the column lock and "Pull Key wait 10 sec" message I have had to deal with since it was new.
recently that error message completed immobilized the car thinking it was being stolen.

After that was completed and worked like a dream. (thank you compliance parts!!!)
The odd thing is that now the interior dash lights seem to be working normal????????
I am still working on this currently.

Missileboy

I would pull the codes as well just to make sure something isn't lurking in the background.

cls241

Thanks for all the info...
All the other outside lights work, break lights, reverse, turn signals, etc. I should not get the column lock issue on a 2001 6-speed, I believe I read the 2001 Manual (not Automatic) is not affected.

I was told I might get the pull-key-wait-10 from the seller; he has that issue on rare occasions.

He said with the Twilight, sometimes they would not come on, so he would pull off the road, turn the car off, wait a few seconds, turn it on, and the headlights would pop up. No such luck for me.

Right, ALL the Dash Lights come on without issue when I turn the car off and 30 seconds after exiting. The under-dash lights work as well. I have checked the dimmer switch, and it makes no difference on the dash lights with the car running. All the way left or right, still no dash lights.

I will tell the shop (I'm bringing it at 8 a.m. on Friday) that maybe the LCC5 Module is appropriate for this iteration.

Someone on a local FB Corvette Group thinks it may be the BMC Module, so I will tell the repair shop that may worth checking, I hope not that's an expensive piece, but I assume little labor.

I will still try the battery when ti warms up a bit, it finally hit 50, so warming up. Only 9am here.

Regardless I want the shop to check out the car, all the fluids, breaks, belts, filters, etc.

Thanks, will report if anything works or I find some Gremlin repellant.

cls241

Thanks, will have the auto shop do that when I drop it off on Friday morning, hoping they can find an answer. I am not a mechanical person, I need to rely on the expertise of others!

Vetteman Jack

Moved to C5 Tech for further discussion.

cls241

Thanks, I saw many other similar topics in General, so I was unsure when I posted it last night. Appreciate the understanding and the support this forum has shown myself and others.

TonyCorvette_

Howdy, my initial thought is a bad MFS but you really need to turn sentinel off first to isolate the issue.

cls241

Thanks I found this online ---> To turn off the Twilight Sentinel on a C5 Corvette, you can pull relay #44 in the fuse box located under the carpet in the passenger footwell. The relay is labeled ALC/HDLP.

I will share it with the shop when I bring it in on Friday morning.

10-min ago I disconnected the ground on the battery, and the headlights popped up a bit. Maybe it's a good sign, maybe not. I am waiting a 1/2 hour or more per other posts and will reconnect the batter and start the car and see if anything has changed. Now that it's daylight not sure what will happen. I printed out your diagram and will bring that as well.

Thanks.

C5MSG2004Vert

I agree. Without any other info it looks like it's the switch. The BCM can turn on the dash independenly from the MFS. There are other relays and fuses involved with the head lamps and their controller. It's not a very simple system the revelant ckts need to be checked.

cls241

Update

I disconnected the black/ground from the battery and let it sit like that for about 40 minutes. As soon as I disconnected it, the lights popped up, odd, unsure why.

When I reconnected it, the headlights closed.

When I stopped for gas, I was in the shade; once I started the car, the headlights popped up and turned on. I drove that way for a while, stopped at Safeway and turned them off using the left rocker arm, they closed. When I got done at Safeway, I headed home. I can't manually turn them on right now, so I will have to wait until tonight to see if they come on when I start my car in the driveway.

I don't know about the dash lights yet.

Pics below.



Disconnected the negative/ground on the battery and the headlights popped up.

Was getting gas ($$$$) and in the shade and when I turned the car on, the headlights turned on, so that's a positive sign.

The car... stopped at Safeway.