Longhorn Upfitters Knowledge Center

Everything You Need to Know About Spray-In Bed Liners

Bobby X

Published on: 07/08/2026

Professional Controlled-Environment Spray Booth

Resource Center

The Complete Guide to Choosing the Right Truck Bed for Your Work

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Published on: 03/08/2026

Whether you're replacing a damaged bed, upgrading your current truck, or building a new work vehicle, Longhorn Upfitters helps contractors, municipalities, utility companies, fleet managers, and business owners find the right solution for the job.

Resource Center

If your truck is experiencing issues after a flatbed, service body, liftgate, crane, or other upfit installation, these frequently asked questions can help you understand common causes. If you're unsure, schedule an inspection with Longhorn Upfitters before the issue becomes worse.

Lighting & Electrical

Why did my trailer lights stop working after replacing my truck bed?

Replacing a truck bed can sometimes affect the trailer wiring harness. Loose connections, damaged wiring, blown fuses, poor grounds, or stretched harnesses may prevent the trailer lights from operating correctly.

Why do my flatbed lights flicker?

Flickering lights are commonly caused by:

Loose ground connections

Damaged wiring

Moisture inside connectors

Poor electrical connections

Overloaded circuits

The electrical system should be inspected before adding additional accessories.

Why is my truck showing a warning light after an upfit?

Do not immediately clear dashboard warning lights. Take a picture of the warning message and contact the installer. Warning lights may indicate issues involving sensors, cameras, wiring, lighting circuits, or other components affected during installation.

If the warning involves brakes, overheating, fuel leaks, or another serious safety concern, stop driving the truck until it has been inspected

Fuel System Problems

Why won't my truck take fuel after a flatbed installation?

If your truck suddenly won't accept fuel after a flatbed installation, stop trying to force fuel into the tank. The fuel-fill hose or vent hose may be kinked, pinched, installed at the wrong angle, or otherwise restricted. Longhorn Upfitters can inspect the fuel-fill system and correct installation-related problems before they lead to additional damage.

Why does the gas pump keep shutting off while fueling?

A fuel nozzle that repeatedly clicks off usually indicates restricted fuel flow or improper tank venting. Common causes include:

-Kinked fuel-fill hose

-Pinched vent hose

-Incorrect filler-neck angle

-Improperly mounted fuel-fill assembly

-Poor hose routing

A professional inspection is recommended.

Why is fuel backing out of the filler neck?

Fuel spilling from the filler neck is a sign that fuel cannot enter the tank properly. Stop fueling immediately and have the fuel-fill and venting system inspected. Continuing to force fuel into the tank can create a serious fire hazard.

Why did my fuel gauge stop working after an upfit?

A damaged, disconnected, or pinched wiring harness may prevent the fuel gauge from reading correctly. The wiring, sending unit, grounds, and electrical connections should all be inspected.

Cameras & Parking Sensors

Why did my backup camera stop working after my flatbed was installed?

The factory camera may have been disconnected, damaged, relocated incorrectly, or connected using an incompatible extension harness. Longhorn Upfitters can inspect the camera system, wiring, mounting location, and programming requirements.

Why are my parking sensors constantly beeping?

Parking sensors may give false warnings if they're installed at the wrong height, wrong angle, damaged, or blocked by part of the new bed or bumper. The sensors, brackets, and wiring should be inspected.

Flatbed & Service Body Problems

My flatbed is making noise while driving. Is that normal?

The truck bed itself should not shift, bang, or move excessively. Loose mounting hardware, worn isolators, improper mounting, cracked brackets, or contact between the bed and frame can all create unusual noises.

Why is my flatbed sitting uneven?

An uneven flatbed may result from improper mounting, suspension issues, damaged mounting hardware, frame concerns, or uneven weight distribution. The truck should be inspected before further use.

My flatbed is touching the truck cab. Is that dangerous?

Yes. There should always be proper clearance between the flatbed and the cab. Contact between the two may indicate loose mounting hardware or an improperly positioned bed and should be corrected immediately.

Why does my truck ride differently after installing a flatbed or service body?

Additional equipment changes the truck's weight distribution, braking characteristics, and suspension performance. If the truck leans, sways, bottoms out, or handles unusually, have the suspension, axle loads, and weight distribution inspected.

Why are my tires rubbing after my truck was upfitted?

Tire rubbing may result from excessive weight, suspension sag, incorrect wheel offset, poor equipment placement, or insufficient clearance. Continued operation can damage the tires and create a safety hazard.

Liftgate Troubleshooting

My liftgate stopped working. What should I check?

Verify that the truck battery is fully charged and the liftgate's main power switch is turned on. Also inspect the circuit breaker, battery connections, wiring, and controls. Never bypass the liftgate's safety systems or work beneath a raised platform.

Why is my liftgate moving slowly?

A slow liftgate may be caused by low battery voltage, poor electrical connections, low hydraulic fluid, a weak motor, a failing hydraulic pump, or excessive weight on the platform. If the liftgate jerks, leaks, or cannot support its load, discontinue use until it has been inspected.

Truck Crane Troubleshooting

My truck-mounted crane isn't working properly. What should I do?

Stop using the crane immediately and remove the truck from service until it has been inspected. Crane problems may involve electrical systems, hydraulics, structural components, stability issues, or overload conditions. Never attempt to repair or operate a crane while supporting a load.

Inspections & Repairs

Can Longhorn Upfitters inspect work completed by another installer?

Yes. Longhorn Upfitters can inspect many flatbed, service body, liftgate, crane, lighting, wiring, hitch, and accessory installations completed by other companies. We can identify visible installation concerns and provide recommendations for repairs or corrections.