My front windshield wipers will only work on high. Any suggestions?

You didn't take into account the wiper switch is a input to the BCM - body control module ,or do you know that ? The BCM controls wiper one an wiper two relay's to turn on the wipers .
Wondering if it is the PCB or perhaps a physical problem? Guessing never finds the problem . Reading how they work in factory service repair info should be the first step for someone that doesn't know .
Intermittent Operation
Windshield wiper DELAY operation is a low speed wiper motor function with a variable delay interval between the wiper motor cycles. The DELAY interval is determined by a series of 5 resistors within the wiper/washer switch. During DELAY wiper operation, the signal circuit voltage is further reduced through the DELAY resistors. The body control module (BCM) monitors the voltage on the signal circuit to determine the delay interval between the low speed wiper motor cycles.
If the wiper switch is moved from a longer delay interval to a shorter delay interval, the BCM will command an immediate wipe cycle and reset the delay timer to the shorter delay interval.
Additionally, intermittent wiper operation is vehicle speed sensitive. As vehicle speed is increased or decreased, the wiper interval will also increase or decrease.

Low Speed Operation
When the wiper switch is in the Low position, voltage is supplied through an internal resistor to the signal circuit. The body control module (BCM) monitors the windshield wiper switch signal 1 circuit and energizes the wiper 1 relay which will operate the windshield wiper motor. The wiper motor will operate at low speed, since the wiper 2 relay is de-energized. Low speed can also be commanded with a scan tool by commanding Wiper Relay Cmd. ON and OFF.
High Speed Operation
In the High position, the windshield wiper/washer switch supplies voltage to both the wiper 1 and wiper 2 relay coils. This energizes both relays and allows battery voltage from the wiper 1 relay switched output to the switched input of the wiper 2 relay through its contacts and out the switched output of the wiper 2 relay to the high speed circuit of the windshield wiper motor. The windshield wiper motor will operate at high speed. During HIGH speed wiper motor operation, the wiper switch signal circuit is at the LOW speed signal voltage, and the body control module (BCM) supplies redundant voltage to the wiper relay via the wiper diode.

Wiper/Washer System Components
The Wiper/Washer System consists of the following components:
• Windshield wiper/washer switch
• Body control module (BCM)
• Wiper 1 relay
• Wiper 2 relay
• Wiper diode
• Windshield wiper motor
• Windshield washer pump
• Windshield washer nozzles
• Windshield washer solvent container
• Windshield wiper arm and blade assemblies
• Windshield wiper transmission
• WIPER/SW 10A fuse
• WIPER 25A fuse
Refer to Master Electrical Component List.

DTC B3715 02: Front Wiper Relay Drive Circuit Short to Ground
DTC B3715 05: Front Wiper Relay Drive Circuit Short to Battery or Open

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

In the under hood fuse box , should have diagram inside the lid . Front wiper's or rear ? Front fuse # 36 - 25 amp. Plus Two relay's PCB hi and Wiper PCB relay . Wouldn't think this being fuse problem . Wiper switch , motor etc... The wiper's are control by a computer . BCM - body control module .

The windshield wiper/washer system consists of front and rear wipers. The front and rear wipers are operative when the vehicle is in accessory or run. The front wipers have 4 different modes: Mist, Intermittent, Low, and High. When the front wipers are in the intermittent mode, there are 5 delay modes to chose from, commanded by the windshield wiper washer switch through the body control module (BCM). The rear wipers has an only one mode.

If the fuse is bad , could have a short to ground or wiper motor pulling to much current (amps) . Fuse's don't just blow for no reason ! Could also have DTC'S - diagnostic trouble codes stored in the BCM .
DTC B3715
DTC B3873
DTC B3875
DTC B3922

DTC B3715 02: Front Wiper Relay Drive Circuit Short to Ground
The body control module (BCM) controls the wiper motor based on input from the windshield wiper washer switch. The BCM monitors the wiper washer switch through three separate signal circuits and a ground circuit. The windshield wiper switch high signal circuit is used to determine high speed wiper operation, the windshield wiper switch low signal is used to determine low speed, intermittent, and mist operation through the use of a resistor ladder, and windshield washer switch signal circuit is used to determine washer operation.
The BCM controls the windshield wiper motor through two output controls, controlling two different PCB relays which control the desired wiper speed, high or low.
DTC B3922 00: Front Wiper Function Select Circuit

The PCB relay's are non- servicable , replace fuse box . Soldered in Your best bet mit be to take it to a qualified repair shop .

There is a electric motor that pumps washer fluid . Located in the bottom of the washer fluid tank .
Wash Operation (Front and Rear Wipers)
The front and rear washer systems use the same windshield washer fluid pump. When either the front or rear wiper is in the washer position voltage will be supplied to one side of the windshield washer fluid pump (depending on whether it is front or rear), while the other side of the pump is grounded.
At this point, the windshield washer fluid pump sprays solvent onto the windshield. When the front or rear washer is activated, the BCM receives an input from the switch that is activated. The BCM will control the wipers while in the WASH mode. The BCM will control either the front wiper relay or the rear wiper relay to turn on the wipers. The windshield wipers operate at low speed for 3 swipes and returns to the park position.

When turning on the washers do you hear the motor run ? Have some one try it while you listen at the washer fluid tank ! These pump motors do go bad .
turn OFF the ignition.
Disconnect the harness electrical connector of the windshield washer fluid pump.
Connect a test lamp from the windshield washer pump control circuit to a good ground .
Turn ON the ignition, with the engine OFF.
Press the front washer switch.
Does the test lamp illuminate?
YES or NO !

Check your manual for wiper fuse & relays location.You can inspect fuses visually...hope this helps

The rear wiper has its own pump motor. pull the hose from the wiper and have someone engage to see if there is a clog. do the same at the motor. if bo liquid comes out then its the pump. also check fluid level in reservoir as well as a possible secondary reservoir

unhook the hose at the rear wiper,test, maybe the nozzle is plugged, or hose bent.

More than likely you need to replace the front windshield wiper motor. You should unplug the motor and check the plug for voltage, checking each terminal as you change the speed selection on the switch. This should help determine if it is a power problem, switch problem, or motor problem.

2 ways of dealing with this. Install a new motor or put up with it until you install a new motor. I usually give it a very light tap with a hammer or a wrench & they start working fine at least for a while

If the Fuses are good and the Rear Works the Cause will be the Wiper Motor for the Windshield Wipers. Please Rate My Response! Thanks!

Your rear bottle for the wipers should be at the back of the vehicle.Look in back for removable panel and bottle should be there.Turn your ignition on(no start)and activate rear washer Listen for the sound of the motor