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Electrical & Hydraulic

Apparatus Electrical & Hydraulic Repair. The Gremlins End Here.

Multiplex and 12V electrical, charging systems, scene lighting, warning lights — plus full hydraulic system repair for booms, outriggers, jacks, and cylinders.

Multiplex, 12V, charging, scene lighting
Hydraulic hoses, cylinders, valves, pumps

Electrical gremlins on a multiplex truck don't get diagnosed by reading codes off a generic scan tool. They get diagnosed by someone who knows the difference between a Class1 IO module, a Weldon V-MUX node, and an Innovative Controls multiplex panel — and who's traced the harness on apparatus from the 1990s through last year's deliveries.

Electrical gremlins die when somebody actually traces the harness.

Intermittent electrical faults on a multiplex truck don't get fixed by guessing. They get fixed by somebody with a wiring diagram, a meter, and the patience to walk the circuit from the multiplex node to the affected output. We've done that work on apparatus from the late 1990s through last year's deliveries, on Class1 IO modules, Weldon V-MUX nodes, and Innovative Controls multiplex panels. The gremlins die at our pace, not theirs.

Hydraulic system work.

Aerial outriggers, ladder cylinders, jack cylinders, accessory pumps, valve banks. Hoses fabricated on-site from JIC and ORFS stock — we don't wait three days for a parts house to ship a hose we could've crimped on the spot. Cylinder reseal kits, valve service, manifold work, and pump replacement.

Charging and scene lighting.

Scene lights that get dimmer over the course of a long incident. Batteries that test fine in the morning and won't crank by evening. Alternators that work at idle but won't hold output under load. We test the whole charging system end-to-end — not just "replace the alternator and hope."

Questions about this service

Can you reprogram multiplex modules? +
Yes for Class1 and Innovative Controls within the scope of normal field service — output configuration, switching logic, basic re-mapping. Major firmware-level work that requires OEM dealer tools we route to the original apparatus manufacturer.
Hydraulic hose — can you really fabricate on-site? +
Yes. The mobile units carry a crimper, stock hose, and the common JIC, ORFS, and SAE fittings. Most apparatus hydraulic hoses can be replaced same-visit.
Field-Proven

Recent Fire Truck Repairs.

A representative slice of recent on-site work — the kind of failures that take an apparatus out of service and the kind of fixes that put it back in. Pump packing, DEF system faults, aerial hydraulics, multiplex electrical, brakes, charging systems, and everything in between.

Pump won't draft on the test pit

Rebuilt packing on a Hale Qmax mid-mount; pumped capacity at 150 PSI net pump pressure with paperwork.

Engine 4 — cranks but won't start

Cummins ISL fuel rail pressure fault; replaced high-pressure pump and primary filter; back in service by morning.

Aerial outrigger won't extend

Traced 12V supply fault to a corroded ground stud; replaced harness section; outrigger cycled and locked clean.

Tank-to-pump valve seized after mutual aid

Removed and serviced the Akron actuated valve; flushed debris; re-tested under draft.

Multiplex panel showing all faults

Class1 IO module replacement after a wet-environment fault; reprogrammed and tested every output.

Rear discharge gate leaking under pressure

Replaced seat and seal kit on a Waterous CSU two-and-a-half-inch gate; pressure tested to 250 PSI.

Engine derating mid-response

Detroit DD13 DEF system fault — failed quality sensor and clogged dosing valve; cleared and re-ran regen.

Air brakes won't release after sitting

Replaced moisture-fouled relay valve and added a desiccant cartridge to the air dryer; full system test.

Aerial rotation slow and creeping

Rebuilt rotation hydraulic motor and replaced worn slew bearing balls; tested full 360° rotation under load.

Scene lights flickering on the foreground

Charging system pulled down by a failed alternator and one weak battery in a four-bank string; replaced both.

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