1999 Chevy Suburban brake/signal light problems please help

[intel.inc]

I have a 1999 chevy burban and for some reason I've having this problem the my one brake on the passanger side won't light up when you press the brake but the other side will. And also when I apply the turning signal on the passanger side it blinks really fast and you can see the front singal flashing fast but the back does not flash at all. So for some reason the brake and signal lights don't work at all on the back passanger side. But the running lights do go figure if any one could help me i would really appreciate it.

[Pamsdad]

They are dual filament bulbs in the tail lights/stoplights.
Check the bulbs. Never rule out the obvious.

Taillight boards are common on these trucks to go bad...

[intel.inc]

I have checked the bulbs and the fuses and everything looks to be fine. I havn't checked the flash relay but why would one side work and not the other.

[Pamsdad]

Completely remove the taillight housing. Bolted to it is the Tail light circuit board(held on by 2 screws). These are very common to go bad.

GM Part No. RH 16511566
LH 16511565

[intel.inc]

But it not like they don't light up at all. They will light up if I just have the running lights on and also if I have the reverse lights on. That all works what doesn't work is when I step on the brake and when I use the turn signal it flashes really fast in the front and you caqn see it but it does nothing in the back. Do you think replace the circuit board will still help it?

[Pamsdad]

Their are 4 possibilities here...

Bulb. Tail light circuit board. Bad connection somewhere. Broken wire.

From your posts, everything works fine, Left & Right, except the right side Stop/Turn signal light. If BOTH filaments in the bulb are good, bulb is OK. Check the connection in the circuit board(where the bulb plugs in). Check the weatherpack connector that plugs into the circuit board.

If you haven't found it by now, start tracing the wire forwards...

[intel.inc]

Yah well what really throws me off is the the running lights and reverse lights work on the back just the signal and the brake don't work. So if the running/reverse lights are working then its getting some kinda of current back to the lights. It just don't light up brighter when you hit the brake and doesn't flash when you hit the turn signal.

[Pamsdad]

I don't think you understand DUAL FILAMENT ...

[EdH]

Replace the brake/turn signal bulb.

[intel.inc]

all the bulbs are ok. I checked all of them in the front and the back. The back bulbs light up when the running lights are on they just don't get brighter when I hit the brake or engage the turning signal. The frint turning signal will flash. but it flashes really fast. Which when I first seen it I figured a bulb was bad so I went and bought bulbs but non of the bulbs were bad when I took off the light cover. The connection looks clean. So I'm not sure why this is happening.

[danvan]

I have the exact same issue on my 99 Sub. Have you figured out your problem? Any help would be great.

[coogmom]

Hey had same problem with my 99 suburban. I did change bulb and it now works fine. Got other probs. LoL.
replace bulb only few bucks just give it a try.

[SpitAndDirt]

I'm in agreement with PamsDad. I don't think you guys are understanding what we are getting at. The bulbs are dual filiment, meaning that if you turn on the running lights, the smaller filiment will illuminate. If you hit the brake or turn signal, the larger filiment will illuminate. Try removing both tail lamp assemblies and swapping them side to side. Just plug them in and let them dangle from the sides of the truck. Then see if your turn signal rapid flashing then follows the lamp assembly. Have a helper handy. If it does follow the lamp assembly, go replace the tailight boards as was suggested already. You were even given part #'s! If the problem does not follow the lamp assembly, then you can try replacing the bulbs themselves, check the sockets for no contact, or end up tracing wires. By the way, do you have a turn signal harness "T" adapter installed for towing? It prevents from having to cut into the factory wires so you can wire up a trailer. Don't count out a bad connection there either if you have one. -Chris

[BF123]

Just to share my experience on a 98 Suburban...
Bulb looked OK but changed it anyway. Circuit board discolored, grease dirty and dried up. Cleaned up board and used new grease with new bulb, worked OK for about a week, then same problem re-appeared. Changed circuit board with part number from Pam's Dad (Thanks!). Now working Fine.

[QuasarTechnician]

Hey Gang,
I own a 99 'burb. Got tired of buying new circuit boards at $75 each.
The problem appears to stem for a poorly designed plastic to metal
fit in the center light bulb contact point. It probably happened during
the strike that occured during the production of '99 Suburbans. Some
Quality Control guy wasn't watching is my theory.
To test your circuit board for the problem I have seen on several
'burbs, just clean the contacts - ESPECIALLY IN THE MIDDLE BULB
SOCKET - then wiggle a good bulb right and left with the turn signal
on. If it starts flashing when pushed to one side (7 out of 8 that I
have found are that the bulb lights up when it is pushed to the inside)
put a small bit of cardboard into the plastic grove to hold it solidly
to that side. It is just plastic there and doesn't touch any contacts,
just the side of the bulb. Remember to replace the cardboard when
you get a new bulb down the road a piece.
Hope this saves you some money and aggravation.
Quasar