Your reefer just stopped cooling. The emergency is the load, not the trailer.

The trailer is fine. The load is on a clock.

A reefer that stops cooling is a different kind of breakdown. The tractor runs, the trailer rolls, nothing is blocking a lane — and it is still the most time-critical call there is, because the emergency is not mechanical. Behind the doors is freight with a temperature window written into the contract, and the moment the unit stopped, that window started closing.

So judge everything in the next hour against one question: does this protect the load's temperature, or spend it? Diagnosis is worth minutes. Keeping the doors shut is free. Opening the box to check the product at every stop is how a repairable afternoon turns into a rejected load.

Four decisions, in the first ten minutes

Before any repair conversation happens, four things need answers, and they need them in this order.

• What the temperature is right now. Not what it should be — what the controller says the box is, and what the setpoint is. Write both down with the time. Every conversation after this runs on those two numbers and the gap between them.
• What the product is. Frozen, fresh, or one of the loads that rides close to its limit by design. Ice cream and produce do not have the same afternoon. The bill of lading says what you are carrying and usually what it should travel at.
• How long the box will hold. A sealed, properly pre-cooled trailer holds temperature far longer than an opened one, and a full box longer than a half-empty one. Nobody can give you a number from the roadside, but you protect the answer by leaving the doors alone.
• Who has to be told. Dispatch first, then the load's owner or the broker — early, not after you have run out of ideas. The decisions that follow are theirs, and every one goes better with more window left.

Fuel first, then the display

The reefer runs on its own small diesel tank, separate from the tractor's, and running it dry is one of the most common reasons a trailer goes warm. Check the level by eye rather than trusting a gauge, and remember that a unit which ran itself empty may need bleeding before it restarts. That check costs nothing and settles a surprising share of calls.

Then read the controller. Modern units post alarm and fault codes on their own display, along with setpoint, return air and discharge air temperatures. Write down exactly what it says, code numbers included — the codes are specific to the maker and model, and a technician can often tell from the number alone whether this is a fuel, power, sensor or refrigeration fault. Do not clear alarms to tidy the screen.

What the unit is doing narrows it further. Cranking and dying points at fuel or its own battery. Running steadily but not cooling points at the refrigeration side. Dead silence points at power, battery or wiring — some of which is trailer-side and repairable where you stand. A unit running flat out while the box loses temperature is often fighting a torn door gasket or a door that will not latch square: a trailer fault, not a unit fault.

What the driver can safely do

There is a short list of useful things and a shorter list of things not to attempt. If the trailer is on a shoulder, hazard flashers and the warning triangles required by 49 CFR 392.22 come first.

• Leave the doors shut. The cold already in the box is the only asset you have. Nobody looks at the freight until there is a plan.
• Check the reefer's fuel and battery. Fuel level by eye, and battery terminals for corrosion or a loose clamp. Those are the driver-level checks that fix real calls.
• Check the standby lead on an electric-standby unit. A unit set to standby with nothing plugged in sits there doing nothing and looks broken.
• Walk the doors and seals. Torn gaskets, a bent rear frame, a door that no longer latches square. These are trailer faults with roadside answers.
• Park it to help. Shade instead of full sun, out of a live lane, buys the box time for free.
• Do not work on the unit. The refrigeration circuit is sealed and pressurized. Do not open service ports, do not add refrigerant, and do not keep restarting a unit that has alarmed out — you will lose the fault information a technician needs.

Who fixes what — an honest boundary

Here is the part a towing company should say plainly: we do not repair refrigeration units. The unit on the nose of the trailer — its diesel engine, compressor, controller and sealed refrigerant circuit — is specialist work, and when it fails it needs the manufacturer's service network, not a roadside truck with good intentions. Our trailer repair page says exactly this, because a company that will guess at a reefer plant is gambling with someone else's load.

What we do repair is the trailer underneath it: lights, wiring, air lines, brakes, landing gear, doors, seals and tires, roadside, 24 hours a day. Sorting between the two is useful work — describe what the unit is doing and what the display says, and we can usually tell you on the phone whether you have a unit problem for the dealer network or a trailer problem we can already be rolling toward. That distinction stops you spending your window on the wrong calls.

The paperwork that protects the carrier

A temperature failure often becomes a cargo claim weeks later, and by then the only thing between the carrier and the full value of the load is what was written down on the day.

The FDA's Sanitary Transportation of Human and Animal Food rule, at 21 CFR part 1 subpart O, puts specific duties on carriers: providing the operating temperature the shipper specifies, pre-cooling each mechanically refrigerated compartment as the shipper specifies, and keeping written procedures for how that is done, subject to the records requirement in 21 CFR 1.912(b). The same rule says that when anyone in the chain becomes aware of an indication of a possible material failure of temperature control, the food must not be sold or otherwise distributed unless a qualified individual determines the deviation did not render it unsafe. That is why "it warmed up a bit, it is probably fine" is not a call a driver or dispatcher gets to make.

The claim itself runs under the Carmack Amendment, 49 U.S.C. 14706, which governs a motor carrier's liability for loss or damage to cargo in interstate transportation and sets minimum time limits — at least nine months from delivery to file a claim, and at least two years from a written denial to sue. None of this is legal or insurance advice: the specifics of any one claim belong to your carrier's safety department and your insurer.

What to write down while you wait

Keep it factual, timed and boring. A note written on the shoulder carries weight that a reconstruction three weeks later does not.

• Times. When you last saw the unit running normally, when you noticed the fault, and when you called dispatch and the load's owner.
• Numbers. Setpoint, box temperature when you noticed, and readings at intervals afterward. If the unit prints or downloads a temperature log, save it.
• The alarm. The exact code and wording on the display, photographed if you can.
• The load's condition on paper. Seal number, whether the seal stayed intact, and whether the doors were opened at any point, by whom.
• Instructions received. Who told you to do what, and when. Authorization to move the trailer, transfer freight or deliver anyway is the detail people forget to record.
• Photographs. The display, the fuel level, the seal and the unit. Our post on what happens to your load covers the chain-of-custody side.

When the fastest fix is a tow

When the unit needs the dealer, the real question is where the trailer meets the technician — and often the fastest answer is taking the trailer to the repair point rather than waiting for it to come out. That is what our wreckers do: a loaded reefer tows as-is if the freight is secure and the trailer is roadworthy, and the tractor does not have to stay with it, as our post on towing a trailer without its tractor explains. The heavy-duty towing side and the service truck run from the same Liberty yard, so one call covers whichever it turns out to be.

One honest note about our yard at 2751 Liberty Landing Rd. A trailer can stand there while decisions get made, but a reefer with a dead unit is not refrigerated storage and we will not pretend otherwise — we hold perishable freight only as long as its owner instructs. If the right move is straight to the dealer's gate or to a cross-dock the owner has arranged, we would rather run it there directly. The load's clock does not stop because the trailer is parked somewhere convenient.

Sources

• 49 CFR 392.22, Emergency signals; stopped commercial motor vehicles
• 21 CFR Part 1 Subpart O, Sanitary Transportation of Human and Animal Food
• 21 CFR 1.912, What record retention and other records requirements apply to shippers, receivers, loaders, and carriers engaged in transportation operations?

Related reading

DOT Out of Service: Faults That Freeze a Running Truck — An out-of-service order means the vehicle legally cannot move until the listed fault is repaired, even if it runs perfectly.

Trailer Brake Dragging or a Hot Hub: Roadside Fix or Tow? — A dragging trailer brake heats one hub, and a hot hub can end in a wheel-off or a fire.

Hot Shot Truck Broke Down: Who Actually Tows It? — A hot shot — a one-ton or medium-duty pickup pulling a gooseneck or flatbed — sits in a gap.