2008 Silverado Fuel Pump Relay Location: The Complete Owner’s Guide
The bottom line up front: On a 2008 Chevrolet Silverado, the fuel pump relay is located inside the under-hood fuse and relay box, commonly called the Power Distribution Center (PDC), which sits on the driver’s side of the engine bay near the firewall or strut tower. The relay is labeled "FUEL PUMP" in the diagram printed on the underside of the box lid, and it is the first component you should check when your truck cranks but will not start .
This guide walks you through exactly where to find the relay, how to test it, how to swap it with a known-good unit, and what to do when the relay is not the problem. You do not need a mechanic for the basic checks covered here, and most of the steps take less than 15 minutes with no special tools .
Where Exactly Is the Fuel Pump Relay on a 2008 Silverado?
Open the hood and look toward the driver’s side of the engine compartment. You will see a large black rectangular box, usually positioned between the battery and the firewall. This box is the Power Distribution Center, and it holds dozens of fuses and relays for the entire truck .
Here is how to find the fuel pump relay in under a minute:
Step 1: Pop the hood and locate the PDC. It is the biggest fuse box in the engine bay, and its cover is typically secured with two clips or a quarter-turn latch.
Step 2: Remove the cover and turn it over. The underside of the lid has a diagram that identifies every fuse and relay in the box. Look for a label that reads FUEL PUMP or FUEL PUMP RELAY .
Step 3: Once you spot the label on the diagram, match it to the physical layout inside the box. The fuel pump relay is a standard 5-pin ISO mini-relay, square-shaped and slightly larger than the blade fuses around it. On most 2007–2013 GMT900 trucks, it sits in one of the middle rows, often near the ignition relay and the fuel pump fuse .
If the label on your lid is faded or missing, do not guess. Check the owner’s manual, which contains the same fuse and relay map for your specific engine variant (4.8L, 5.3L, or 6.2L) .
Why the Relay Location Matters So Much
The fuel pump relay is the electrical switch that connects battery power to the fuel pump when you turn the key. The engine control module (ECM/PCM) sends a low-current signal to the relay, which then closes a heavier circuit that delivers 12 volts to the pump inside the fuel tank .
If this relay fails, the fuel pump receives no power. The engine will still crank because the starter has its own circuit, but it will not fire because no fuel reaches the injectors. This is one of the most common causes of a no-start condition on this generation of Silverado, and it is also one of the cheapest fixes if you diagnose it correctly .
The relay failure rate climbs noticeably on trucks past 120,000 miles, especially in hot climates where the under-hood heat degrades the relay contacts over many summer seasons .
How to Test the Fuel Pump Relay in 5 Minutes
You do not need a multimeter or a test light for the first and most effective test. You only need another relay of the same type.
1. Turn the key to the RUN position without starting the engine. Listen near the fuel filler neck for a 2-second whirring sound. That is the fuel pump priming. If you hear nothing, you have no power reaching the pump, and the relay is your prime suspect .
2. Open the PDC and locate the fuel pump relay. Pull it straight up with a firm grip or a relay puller pliers if you have one. A small pair of needle-nose pliers also works .
3. Find an identical relay in the same box. The A/C compressor relay and the horn relay use the same 5-pin configuration on most Silverados. Pull one of those out and push it into the fuel pump slot .
4. Turn the key to RUN again and listen for the prime. If you now hear the pump whir, the original relay was dead. Replace it with a new one and move on .
If the truck starts after the swap, your problem is solved. A replacement fuel pump relay costs between $6 and $15 at any auto parts store, and common part numbers include GM 15321059, AC Delco D1750C, or Standard Motor Products RY-601 .
What If the Relay Was Not the Problem?
If you swapped the relay and the pump still stays silent, work through these checks in order.
1. Check the fuel pump fuse. The fuse sits in the same PDC, usually one slot over from the relay. Pull it and inspect the metal element inside. A blown fuse will have a visible break or a dark, melted look. Replace it with a fuse of the same amperage, never higher .
2. Check for voltage at the relay output. With the key in RUN, use a test light or multimeter to check for 12 volts at the relay socket terminal that feeds the pump. If you have power at the relay but no pump activity, the problem may be in the wiring between the relay and the tank, or the pump itself has failed .
3. Listen closely for the pump. The fuel pump on a 2008 Silverado lives inside the fuel tank. If the relay clicks when you turn the key but the pump does not whir, the pump motor may be dead. Silverado fuel pumps typically last between 120,000 and 200,000 miles, but regular driving on a low tank can shorten that lifespan considerably .
4. Check for a stored crash flag. On some GMT900 trucks, a minor collision that did not deploy the airbags can set a "crash event stored" flag in the body control module. The PCM then keeps the fuel pump relay open until the flag is cleared with a scan tool. If your truck was in any recent incident, scan for body codes with an OBD-II tool that reads chassis codes .
5. Verify the crank position sensor. A failing crank sensor will keep the engine from starting, but the fuel pump will still prime when you turn the key. If you hear the pump prime and the engine cranks but does not catch, the crank sensor is a strong suspect .
Understanding the Fuel Pump Circuit
Knowing how the system works helps you diagnose faster. Here is the simple version of what happens every time you start your truck :
1. You turn the ignition to the ON position.
2. The ECM/PCM sends a signal to the fuel pump relay, closing the switch.
3. Battery voltage flows through the fuel pump fuse to the relay, and from the relay to the fuel pump.
4. The pump pressurizes the fuel rail for roughly two seconds, then stops until the engine cranks.
5. Once the engine is running, the ECM keeps the relay energized to maintain continuous fuel flow.
If any link in that chain breaks, the pump does not run and the engine does not start. The relay is the most vulnerable link because it is an electromechanical part exposed to engine bay heat, and it wears out more often than fuses or wiring .
Common Symptoms of a Failing Fuel Pump Relay
Before the relay fails completely, you may notice warning signs.
1. Intermittent no-start conditions. The truck starts fine most days, but occasionally cranks without firing. Wait a few minutes, try again, and it starts. This is a classic symptom of a relay with worn contacts that sometimes fail to close .
2. Engine stalls while driving. If the relay loses connection while the engine is running, power cuts to the pump and the engine dies immediately. This is one of the most dangerous symptoms because it can happen in traffic without warning .
3. The pump runs at low speed or not at all. A corroded relay can add resistance to the circuit, causing the fuel pump to run slower than it should. This translates into low fuel pressure, which you may feel as a lack of power under acceleration .
4. No prime sound at key ON. This is the easiest symptom to notice. Turn the key to RUN and listen for the brief whir from the fuel tank. No whir equals no power to the pump, and the relay is the first thing to check .
Why You Should Consider a KEMSO Fuel Pump for Your Silverado
If your testing confirms that the relay is good and the fuel pump itself has failed, the next step is choosing a replacement. The fuel pump is the heart of your fuel delivery system, and choosing a low-quality part can leave you stranded again within a year.
KEMSO specializes in manufacturing high-performance fuel pumps that meet or exceed Original Equipment specifications. Every KEMSO pump is built with precision tolerances to deliver consistent fuel pressure and reliable flow, which matters for both everyday driving and towing applications.
Here is what you get with a KEMSO Fuel Pump:
1. High-Performance Engineering. Each pump is bench-tested to ensure it delivers the correct flow rate and pressure for the vehicle it is designed to serve.
2. OEM Replacement Quality. KEMSO pumps are designed to be direct replacements, meaning they bolt in with no modification to your fuel tank or wiring harness.
3. Lifetime Warranty. KEMSO stands behind every pump with a lifetime warranty, giving you peace of mind that your replacement will last.
If you need a new fuel pump, visit the KEMSO website to browse their full catalog and find the correct pump for your 2008 Silverado. Their product lineup includes pumps for a wide range of domestic and imported vehicles, and their customer reviews show consistent satisfaction with performance and durability.
Visit the KEMSO store at: https://www.kemsoracing.com/
A Full Diagnosis Order for a No-Start Silverado
If your truck cranks but will not start, follow this exact order. It takes about 15 minutes and requires no special tools :
1. Turn the key to RUN, engine off. Listen for the 2-second pump prime at the fuel filler neck. Go to step 2 regardless of whether you hear it, but take note.
2. Open the under-hood fuse box. Remove the fuel pump relay.
3. Swap it with an identical relay from the A/C compressor or horn slot.
4. Turn the key to RUN again. If the pump now primes, the relay was bad. Replace it and you are done.
5. If the pump still does not prime, check the fuel pump fuse. Pull it and inspect the element.
6. If the fuse is good, use a test light to verify power at the relay socket with the key in RUN.
7. If you have power at the relay but no pump activity, listen at the tank again. If the pump is silent, it is likely dead.
8. Scan for body codes to rule out a stored crash flag, especially if the truck was in any recent incident.
9. If everything checks out and the pump is still silent, the wiring between the relay and the tank needs a closer look, and a fuel pressure test gauge will tell you for certain whether the pump is delivering pressure .
When to Let a Professional Handle It
The relay swap and fuse check are safe for any owner to do. But once you move past those steps, you are dealing with the fuel system, which involves pressurized fuel lines and the fuel tank itself. If you find a wiring issue or need to replace the fuel pump, that job involves dropping the fuel tank or removing the bed on many trucks.
If you are not comfortable working around fuel lines, have a qualified technician finish the diagnosis. There is no shame in knowing your limits, and a professional will have the right tools and a service manual for your exact engine variant .
The Bottom Line
On a 2008 Silverado, the fuel pump relay lives in the under-hood fuse box on the driver’s side, and it is the number one thing to check when the truck cranks but will not start . A $10 relay replacement is the most common fix for this problem, and you can confirm it in five minutes by swapping relays with a known-good unit .
When the relay tests good but the pump does not run, check the fuse, verify power at the relay, and scan for body codes. If the pump itself is dead, choose a quality replacement. KEMSO fuel pumps offer high performance, OEM-grade reliability, and a lifetime warranty, and they are available at https://www.kemsoracing.com/.
Take care of the little electrical parts first, and keep your Silverado running for many more miles.