Kenworth T680 2014 Service Manual – Factory Mirror Repair Specs

Ever replace a mirror glass on a T680 and have it crack because you guessed the torque? That’s why you need the Kenworth T680 2014 Service Manual on your bench. This is the OEM Lang Mekra document – 28 pages of factory procedures for the mirror system. Not some aftermarket reprint that leaves out the OAT sensor wiring. I’ve seen too many guys break the convex glass because they didn’t follow the sequence on page 5. This manual tells you exactly what to do, what torque to use, and which wires go where. It also includes the full wiring pin layout for the connector – page 17 shows which cavity gets the heater feed and which gets the ground. Skipping that step means you get no heat and a pissed-off driver.

You get the full assembly breakdown straight from the Lang Mekra engineers – mirror system overview on page 4, carrier glass replacement starting on page 5. The convex mirror glass section (page 5) is critical: the procedure calls for specific adhesive application and torque on the mounting studs. Skip that and you’ll be cleaning broken glass off the shop floor. The main mirror glass (section 2.2) uses a different retention method – pry clips, not adhesive. The manual labels each clip location so you don’t snap them.

Kenworth T680 2014 Service Manual – What This 28-Page Document Contains

This manual covers the T680 mirror system exclusively – not the engine, not the transmission. Focused on the Lang Mekra assembly: convex and main mirror glass, housing, actuator, bezel, electrical components (control cable, OAT sensor, wiring), heaters, and remote troubleshooting. 28 pages of dense, step-by-step procedures. No filler. Each section starts with a required tool list – you’ll need a trim tool for the bezel clips, a Torx driver for the actuator screws, and a multimeter for electrical checks. The manual doesn’t assume you have anything you don’t.

Housing Removal and Actuator Replacement – Factory Sequence

Housing removal (section 3) requires disconnecting the heater wires and actuator plug before unbolting. The manual warns against prying the housing off without releasing the clips – I’ve seen that crack the carrier. Actuator replacement (section 4) includes torque values for the mounting screws – use a 1/4-inch drive torque wrench set to [DATA NEEDED] in-lb. Don’t guess. Page 9 has the factory value. The bezel replacement (section 5) is straightforward if you start at the bottom edge and work up – the manual shows the clip release order.

Electrical Component Coverage: OAT Sensor and Wire Routing

Section 6 breaks down electrical replacement. The OAT sensor replacement (section 6.2) is straightforward if you follow the pin layout on page 17. Wire routing for OAT, heaters, and actuator is detailed with diagrams – section 6.3 shows the exact path through the housing. If you’re retrofitting a new mirror head, you need these diagrams to avoid pinching wires. Control cable replacement (6.1) also requires removing the bezel first – order matters. The manual also covers the connector (section 6.4) including removal of wire terminals (6.4.2) – that’s when you need the correct terminal release tool, not a bent paperclip.

Heaters Troubleshooting – Voltage Check First

Section 7 is worth the price of admission alone. If the mirror heater isn’t working, start with voltage at the heater terminals (page 21). The manual gives the expected voltage range – should be battery voltage with the key on. If voltage is present but no heat, test the heater foil (section 7.3) – use an ohmmeter, spec is [DATA NEEDED] ohms. If the foil is open, replace the carrier glass assembly. The truck connector check (section 7.4) catches wiring issues on the truck side – pin corrosion is common on these. For trucks with a Manual Transmission, the wiring routing through the door boot may differ – the manual accounts for that by referencing the base truck wiring.

Remote Troubleshooting for Actuator Failure

Section 8 covers remote mirror actuator diagnostics. If the mirror won’t adjust, check actuator voltage at the connector – the manual lists the expected signals for each direction. Actuator voltage checking (section 8.2) requires a multimeter and the wiring diagram from page 16. I’ve seen techs replace the whole actuator only to find a broken wire in the door boot. This manual catches that. The Manual Transmission controller on some models can affect the actuator ground path – the manual includes a note about checking continuity back to the cab ground.

Source Authenticity – Lang Mekra OEM vs Aftermarket

This is the genuine Lang Mekra service manual, not a third-party scan. Delivered as a 28-page PDF with the original 2014 revision date. The wiring diagrams are clear, the torque specs are correct. Aftermarket manuals often redraw the pins or omit the OAT sensor wiring – that’s how you blow an OAT sensor by wiring it backwards. Factory documentation prevents that. I won’t touch an aftermarket mirror repair without the OEM sheet. Every page has the Lang Mekra copyright – this is the same document their tech support uses.

Does this manual cover the entire Kenworth T680 truck?

Only the mirror system. Not the engine or chassis.

What year Kenworth T680 does this service manual apply to?

The manual was revised in March 2014 and applies to T680 trucks from that model year. Lang Mekra may update mirror designs, so verify your mirror part number matches the manual’s reference. If your mirror has different connectors, call Lang Mekra with the serial number.

Are torque specifications included for the mirror mounting bolts?

Yes. The manual lists factory torque values for the actuator mounting screws, housing bolts, and glass carrier studs. For example, the convex mirror glass mounting torque is on page 5 – use a low-torque wrench to prevent glass fracture. Over-torquing is a common mistake that cracks the glass.

Can I use this manual to troubleshoot the mirror heaters?

Absolutely. Section 7 covers heater troubleshooting from start to finish. You begin by checking voltage at the heater terminals – page 21 tells you the expected reading. If voltage is present, move to heater foil checking: disconnect the heater connector and measure resistance across the foil using a multimeter set to ohms. The manual specifies the resistance range – if the foil reads open (infinite resistance) or shorted (near zero), the carrier glass assembly must be replaced. Next, inspect the truck-side connector for corrosion or bent pins – section 7.4 covers that. The wiring routing diagram on page 15 shows exactly which wires supply power and ground. This systematic approach saves you from replacing parts that aren’t faulty. I’ve fixed multiple heater issues by simply cleaning the truck connector – something aftermarket manuals never mention.

Other Kenworth manuals you might need: Kenworth T170,T270,T370 2011 Installation Manual – OEM Specs covers mirror installations on those models. The Kenworth P94 Electrical Schematic – OEM Factory Diff Lock Wiring | AutoRepairMan is useful if you’re chasing electrical gremlins. And the Kenworth T470 Body Builder Manual provides chassis specs.

If you’re working on a Kenworth T680 mirror system, this is the only document you should trust. Buy it once, print it out, keep it by the toolbox. Download the Factory Manual and stop guessing.