Chevrolet Tahoe Relay Guide: Diagnosing and Replacing (2014-2020)
Understand the signs of a failing relay in your Tahoe and how to choose the right replacement part.
- A bad relay can cause critical issues like a no-start condition, but symptoms vary depending on which relay fails (e.g., fuel pump vs. starter).
- ACDelco is the OEM supplier, so choosing this brand for an aftermarket relay ensures factory quality and fit.
- Replacing a relay is a very simple DIY task that requires no tools and can be done in minutes.
- A Technical Service Bulletin (TSB) for an overheating auxiliary battery relay exists, but it only applies to 2015-2019 Tahoe Police Patrol Vehicle (PPV) models.
The Role of Relays in Your Tahoe
Your 2014-2020 Chevrolet Tahoe relies on a network of relays to function correctly. These small, cube-shaped components are essential for operating systems that draw a lot of power. Instead of running thick, heavy wires all the way to the dashboard switches, a relay allows a small, safe current to activate a high-power device located elsewhere in the vehicle. They are most commonly found in fuse boxes, both in the engine bay and inside the cabin.
Symptoms of a Failing Relay
Because relays are used for many different systems, the symptoms of a failure depend entirely on which relay has gone bad. The two most critical and common relays to fail are for the fuel pump and the starter.
- Bad Fuel Pump Relay Symptoms: If this relay fails, the fuel pump won't get the power it needs. You will likely experience the engine cranking over but refusing to start. You might also notice the engine stalling suddenly while driving, idling roughly, or hesitating during acceleration. A key sign is the lack of a faint humming or buzzing sound from the rear of the vehicle (the fuel tank area) for a couple of seconds when you first turn the key to the 'on' position.
- Bad Starter Relay Symptoms: A failed starter relay prevents power from reaching the starter motor. The most common symptom is a no-crank, no-start condition. When you turn the key, you may hear a single, faint click from the fuse box, but the engine will not turn over at all. In some cases, the problem can be intermittent, working one moment and failing the next.
- Bad A/C Compressor Relay Symptoms: If the A/C relay fails, the compressor clutch will not engage. This results in the air conditioning system blowing air that is not cold, even when the controls are set correctly.
Known Issues for Police Vehicles (PPV)
General Motors issued Technical Service Bulletin (TSB) #19-NA-099 for 2015-2019 Tahoe Police Patrol Vehicles (PPV). This bulletin notes that the auxiliary battery relay can overheat and melt due to the demands of charging the extra battery for police equipment. The fix is to replace it with a more heat-tolerant relay. This issue is specific to the PPV models and does not apply to standard civilian Tahoes.
Choosing the Right Aftermarket Relay
When shopping for a replacement relay, you want a part that matches the original's performance and reliability. For the 2014-2020 Tahoe, the choice is straightforward.
- Brand Quality: ACDelco is General Motors' own parts brand, meaning it is the Original Equipment (OE) supplier for your Tahoe. Choosing an ACDelco relay from an aftermarket seller gives you a part that is identical in quality, fit, and function to what was installed at the factory. It is a trusted brand for GM vehicles and is considered a top-tier choice.
| Part Type | Price Range |
|---|---|
| New OEM / ACDelco | $30 - $50 |
| New Aftermarket (ACDelco) | $18.34 |
| Shop Labor | $50 - $100 |
Pro Tip: Swapping Relays for Diagnosis
If you suspect a relay is bad, you can sometimes perform a quick test. Locate the suspect relay in the fuse box and find another identical relay in the same box that controls a non-essential function (like the horn or rear defogger). Swap the two relays. If the problem moves—for example, your truck now starts but the horn doesn't work—you have confirmed the relay is bad. Always remember to put the good relay back in its original spot if you need to drive to get the new part.
Frequently Asked Questions (FAQ)
Can I replace a Tahoe relay myself?
Yes, this is one of the easiest repairs you can do. It requires no tools. You simply locate the fuse box, use the diagram on the cover to find the correct relay, pull the old one straight out, and push the new one in. The entire process takes only a few minutes.
Where are the relays located on a 2014-2020 Tahoe?
Your Tahoe has multiple fuse boxes. The main one is in the engine compartment on the driver's side. There are also fuse panels inside the vehicle on the driver's and passenger's sides of the dashboard, and sometimes one in the rear cargo area. Your owner's manual will have precise diagrams for your specific model year.
Is a relay the same as a fuse?
No. A fuse is a safety device designed to blow and break a circuit during a power surge to protect a component. A relay is a switch that turns a circuit on and off. While they are both located in the fuse box, they perform different jobs.
Should I replace all my relays at once?
No, this is not necessary. Relays fail individually from wear and tear over time. You only need to replace the specific relay that has failed. It is a good idea, however, to keep a spare multi-purpose relay in your glove box, as they are inexpensive and can be critical if one fails on the road.
Helpful Videos
Technical Specifications
OEM Part Numbers: 13500114 D1741C 13592144
Most relays for this vehicle are 4-pin or 5-pin, 12V, multi-purpose blade-style relays.
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The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
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