Wiring the M460 G Dryer Timer
The M460 G is a mechanical drum timer that shows up in a lot of commercial and heavy-duty residential dryers made in the 80s and early 90s. It's still everywhere in repair shops because these machines outlast the units they came from. The timer diagram you need is straightforward, but getting the colors right on a replacement can bite you if you don't check the existing wiring. I've pulled these timers apart more times than I care to count. Here's how the terminals actually behave on the common 5-terminal version, and what I usually see when a dryer won't advance through its cycle. Terminal layout on the M460 G drum:
- L (Line): This is your hot feed from the control board or directly from the thermal fuse circuit. Usually black on the old units.
- 1 (Common output to heater relay/coil): This is the timed hot feed that gets interrupted when the timer reaches end-of-cycle. Often red or white depending on the manufacturer.
- 2 (Circuit for fan/motor delay): Powers the drum motor after the heater shuts off during the cool-down phase. Usually brown.
- 3 (End-of-cycle signal or interlock): Sometimes wired to the door switch circuit on certain brands. Often orange.
- N or Ground: This one varies by brand. Some M460 G units have a chassis ground tab on the back. Others route neutral through terminal 4.
Here's where people go wrong. The M460 G timer doesn't control the high-voltage heating element directly. It switches low-voltage control power to the heater relay coil or the main contactor. If you're testing continuity with a multimeter and it reads open on terminal 1, that doesn't necessarily mean the timer is bad. Check whether the thermal cutoff fuse upstream has blown. I replaced three M460 G timers in one weekend before I realized the actual fault was a $2.50 thermal fuse that kept failing because someone had bypassed the high-limit thermostat on a previous repair. The one edge case that cost me an hour once involved a Whirlpool dryer where the timer ran but the drum never stopped heating. The diagram said terminal 1 should cut power at the end of the cycle, but I was measuring voltage at terminal 1 even when the timer knob showed "Off." What I missed was that on this particular model year, the M460 G had a dual-switch configuration where terminal 1 only breaks the heater relay feed, not the main drum motor feed. The motor kept running and the heater stayed live because the separate end-of-cycle switch at terminal 3 wasn't making contact. The fix was replacing just the switch contact plate inside the timer assembly rather than the whole unit. A lot of people throw away a perfectly good M460 G because they don't realize the contacts inside can be cleaned with contact cleaner instead. If you're looking at a diagram online, pay attention to the color code. Different manufacturers used different wire colors for the same terminals. A Maytag diagram might show a blue wire on terminal 2 while a Kenmore schematic for the same timer shows green. Always trace the wires from the timer to their destination, not from the diagram to the timer. I label each wire with masking tape before I pull it off the old timer. Takes thirty seconds and saves you from guessing later.
The mechanical aspect of the M460 G is where these things actually fail. The spring-loaded cam inside wears down, and the timer will stutter between settings. You'll hear a clicking sound as the cam jumps instead of sliding smoothly. It's not electrical. It's mechanical friction and metal fatigue. You can buy a rebuild kit for about twelve dollars, but honestly the labor to disassemble the timer housing isn't worth it unless you're doing this for fun. A new timer runs about forty to sixty dollars at most supplier houses. One thing the diagrams don't always tell you: the M460 G has a manual advance lever on the front. If the dryer is stuck in a cycle and the timer won't move, you can push that lever forward to advance the cam. I use this technique when diagnosing whether a Fault is in the timer motor or just a stuck cam. If manual advance works but the timer motor won't turn it, the problem is the small synchronous motor inside the timer housing. Those motors run on whatever voltage the control board supplies them — usually 120 volts AC from the line side. Test it with an ohmmeter. A good timer motor reads between 2000 and 4000 ohms. If it reads open or near zero, replace the motor or the whole timer assembly. When wiring a replacement, torque the terminal screws to about four inch-pounds. Over-tightening cracks the timer's plastic housing, and the M460 G's body isn't exactly reinforced. I learned that one the hard way after stripping a terminal on a $55 replacement and having to source a used one from a salvage yard.
Get the Full Details
Downloadable diagrams exist on sites like AppliancePartsPros, Sears Parts Direct, and some independent repair forums, but the ones that are actually accurate are usually the service bulletins from the original OEMs. If you have the full model number of the dryer, not just the M460 G part number on the timer, you can find the exact wiring schematic in the manufacturer's technical data sheet. That'll save you from matching colors to terminals and guessing which wire goes where. The M460 G timer itself doesn't fail often enough to justify preventive replacement. They last ten to fifteen years in normal use. The things that actually break are the thermal fuses, the high-limit thermostats, and the door switch assembly. Fix those first before you pull the timer. I see a lot of people put a new M460 G in and then wonder why the dryer still won't heat or won't stop heating. Nine times out of ten it's not the timer.
