99 Firebird turn signal/parking light short.

Possibly bad ground connection - G100
In back of the right headlamp on the frame. Headlamps, turn signals, parking lamp for the right all ground at that point. Corrosion in the wire, broken park lamp wire.
Headlamps, turn signals, parking lamp all have their own ground wire that connects at that point.

Hooking up a professional grade scan tool an check for DTC'S - diagnostic trouble codes in the BCM - body control module may point in a diagnostic direction.

DTC B3949: Right Front Turn Signal
Right Front Park/Turn Signal Inoperative

Circuit/System Description
The Body Control Module (BCM) controls the turn signals based on an input from the turn signal switch, part of the multifunction turn signal lever. The BCM receives an input from one of two signal circuits to determine which turn signal function is requested. When the turn signal lever is placed in the LEFT position, the left turn signal switch signal circuit is grounded indicating that left turn signal operation is requested. When the turn signal lever is placed in the RIGHT position, the right turn signal switch signal circuit is grounded indicating that right turn signal operation is requested.
When a turn signal input is received from the turn signal switch, the BCM will activate the appropriate turn signals. The BCM pulses voltage to the applicable turn signals via the turn signal lamp supply voltage circuits, illuminating the required turn signal lamps.

B3949
A short to voltage, short to ground, or an open/high resistance is seen on the right front turn signal lamp supply voltage circuit.

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Turn Signal Lamps
The body control module (BCM) is responsible for controlling the turn signals and hazard lamps. When the turn signal switch is placed in either the left turn or right turn position, the BCM receives a signal from the turn signal switch. The BCM then sends an on-off voltage signal to either the left or right turn signals and their instrument panel cluster (IPC) indicator. When the hazard switch is pressed, the BCM receives a signal from the hazard switch. The BCM then will send an on-off voltage signal to all the turn signal lamps. All the turn signal lamps will flash including both IPC turn signal indicators.
Stop Lamps
The body control module (BCM) is responsible for controlling the stop lamps. When the driver presses the brake pedal, the BCM will receive a signal from the brake pedal position sensor. The BCM then supplies battery positive voltage to both left and right stop lamp assemblies and to the center high mounted stop lamp (CHMSL). The stop lamps are grounded at G401 and G403. The CHMSL is grounded at G302.

Something is messing with the BCM'S mind ,bad input data ,shorted circuit etc... Hooking up a professional type scan tool is needed to read BCM DTC'S - diagnostic trouble codes an view live data to the BCM .

DTC B3948 02: Left Front Turn Signal Circuit Short to Ground
DTC B3948 05: Left Front Turn Signal Circuit Short to Battery or Open
DTC B3949 02: Right Front Turn Signal Circuit Short to Ground
DTC B3949 05: Right Front Turn Signal Circuit Short to Battery or Open

DTC B3950 02: Left Rear Turn Signal Circuit Short to Ground
DTC B3950 05: Left Rear Turn Signal Circuit Short to Battery or Open
DTC B3951 02: Right Rear Turn Signal Circuit Short to Ground
DTC B3951 05: Right Rear Turn Signal Circuit Short to Battery or Open

Your best bet ,take it to a qualified repair shop.

it's the grounds if they're both flashing fast it's definitely grounds take a test light and see if its got power goes through the test light grounded to the frame and if the light comes on then it's definitely your grounds

why skip RR lamp? what does IT DO? be like 1st 1st look.
dim, out, fast?

the rapid is talking to you
it means current is wrong,
shorted, or open lines. to the right.
its the wiring
if the bulbs are like 1157 brass base bulbs
why not replace them first , they can short inside,
asking online for guessing is silly, why listen to 10 examples for this.
but is cut wires.
shorted wires.
keep i mind the blinker asks funny for both opens and shorts
its a feature, that.
low current or too much.

the acid test is connect 2 TEST bulbs in parallel to the multi-function switch output right side,
blinks ok now, bingo bad lamps or bad wiring, from there to the right side.

if the hazard fails you never said????
if rigth front is dim or dead the bulb is blown or shorted
if new bulb there , then the wires are shorted.
to it.
the only help on line worth squat is how to test and use your meter.
you can, check for voltage
you can check continuity on that line (its just 1 wire)
and check for shorts on that wire to ground (lamps pulled right side to do that, lamps read 0 ohms cold)
look for collision damage RF? behind lamp sockets?
be first.
in my book.
looking is always first. sure.


I have your SM book open now, chapter 8w-50
the haz/blink module has just 2 pins, left and right out.
pin 3 on the module runs front and rear blinks, (a fact to know)
RF is BR/RD, brown -red stripe?
all comments USA on USA forum. USA car.
ok?

the right side lamp (sidemaker) only blinks turns if parks ARE oFF

Id try 2 new blinker lamps front and 1 rear.
that be first. or test the lamp on a battery , and no not get burned fingers hot wring a shorted lamp.

wish i knew
what rear did
and what both did on HAZ
out, dim or to fast.

Perhaps a dicky connection somewhere. Perhaps corrosion, even moisture in the connection plugs. Inspect all connections to your indicator lights. Also check for worn or damaged wires. Also Have a look inside the lenses of the lights to see if the the globes are corroded or have water ingress etc and causing shorts to other wiring within the lighting circuits.

You may also consider turn indicator lever to on to indicate truniong right, make sure the engine off. Have someone watch right indicator and literally grab the plugs/leads to the indicator globe and give them a shake to see if the fault goes away. If it doe stop intermitantly then it will help point you in the correct area.

It will turn on when I hit the button and the turn signals do work. All of this has led to my ABS lights to come on as well. ??????????? Your best bet , take it to a qualified repair shop or learn to do better explanation's ! Or lean to do automotive electrical testing .
Basic Electricity for Service Techs Ohm law Current Flow Opens Shorts
Electric Testing Techniques You Need to Know

How to Use Multimeter to Troubleshoot Common Problems

Do you know what a wiring diagram is ? How to use a DVOM - digital volt ohm meter ? Free wiring diagrams here http://www.bbbind.com/free_tsb.html Enter vehicle info. year make ,model and engine size. Under system click on lighting ,then under subsystem click on turn signals . Click the search button then the blue links .Check power an ground circuits ! This is how we diagnose electrical faults , not just replacing parts .

Turn Lamps
Voltage is applied through the TURN fuse and the turn/hazard flasher when the ignition switch is in the following positions:
• RUN
• BULB TEST
• START
The voltage travels to the contact in the hazard switch. The hazard switch is located in the turn/hazard-headlamp switch assembly. This contact is normally closed.
When the left turn signal is turned on, voltage is applied to the following components.
• The left turn indicator
• The left front park/turn lamp circuit 14
• The left rear turn lamp circuit 18
The turn lamps turn on immediately. The current flow heats up the timing element. The timing element is located in the turn/hazard flasher. The timing element repeatedly opens and closes the circuit. This action causes the turn lamps to begin flashing.
The voltage that is applied to the left front park/turn lamp is also applied to the left front marker lamp. If the headlamp switch is in the OFF position, the left front marker lamp will find a path to ground through one of the following lamps. The following lamps provide low resistance paths to ground:
• The right front marker lamp
• The right turn indicator
• The right front park/turn lamps
• The left front park/turn lamps
The left front marker lamp flashes with the turn lamps. The voltage drop across the marker lamp is much higher than the voltage drop across the other lamps. The lamps that are used for the ground path will not flash.
When the headlamp switch is in either the PARK or HEAD positions, voltage is applied through the following components:
• The EXT LP fuse
• The marker lamps
• The park lamps
When the left turn signal is turned on, the left marker lamp will have voltage at both connections. The left marker lamp does not light. When the turn/hazard flasher stops the voltage to the turn lamps, the marker lamp is grounded through the turn lamp. The marker lamp does not go on. The left front marker lamp flashes in the following manner:
• The left front marker lamp flashes on when the turn filament of the left front park/turn lamp goes off.
• The left front marker lamp flashes off when the turn filament of the left front park/turn lamp goes on.
Voltage is applied to the right lamps in the same manner, when the right turn signal is turned on.
Hazard Lamps
Voltage is applied at all times through the following components to the normally open contact of the hazard switch in the turn/hazard-headlamp switch assembly:
• The STOP HAZ fuse
• The turn/hazard flasher
When the hazard switch is turned on, voltage is applied to the following components:
• The front turn lamps
• The rear turn lamps
The following lamps flash on and off:
• All of the turn lamps
• Both of the turn indicators
The front marker lamps flash with the hazard lamps on, just as the front marker lamps flash when the turn lamps are on. If the headlamp switch is in the OFF position, the front marker lamps flash on when the hazard lamps are on. The front marker lights will flash on when the hazard lamps are on if the headlamp switch is in one of the following positions:
• PARK
• HEAD
When the hazard lamps are on, the following conditions apply:
• The turn circuit is always open.
• The turn/hazard flasher controls the lamp.
Park/Marker Lamps
Voltage is applied through the EXT LP fuse, to the headlamp switch at all times. Voltage is applied to the park lamps and the marker lamps when the headlamp switch is in the following positions:
• PARK
• HEAD
The front marker lamps are grounded through the turn filament of the respective front park/turn lamp. The front marker lamps light as a result.
Stop Lamps
Voltage is applied through the STOP HAZ fuse to the brake switch at all times. When the brake pedal is depressed, the brake switch closes. This action applies voltage through the turn/hazard-headlamp switch assembly to the following lamps:
• The high mounted stop lamp assembly
• The left tail/stop-turn lamps
• The right tail/stop-turn lamps

97 chevy blazer left turn signal makes the dash lights flash then when i turn parking lights on left signal stays on constent when engaged

Have you checked to see if your lights work, brake lights and turn signals?

check your wiring harness to breaks and shorts also check to see if water is getting into the turn signal lense through a crack

try making sure all the grounds are good