For all vehicles: Snowmobiles, Motorcycles, All Terrain Vehicles. Assuming your grips were installed per our installation instructions: Resistor: The resistor's only function is when you select the "Lo" switch position: The voltage goes through the resistor before it reaches two heated grips. It creates a voltage drop of one third of the available voltage so that the heated grips produce less heat. When on "Lo" the resistor will get hot, so it must be mounted on a metal heat sink in moving air flow. Do not mount on plastic. Use nylon wire ties, safety wires, hose clamp, or other means to secure it. Do not mount it in an enclosed area where heat can build up. In the cases where the instructions indicate the grips must be wired in "series", (such as model 101,102, 103, 104,105, 201, 202, 203, 204, 205, 301, 401, 501) you must be careful not to wire the grips incorrectly ("parallel") or the resistor might build up so much heat that it melts the resistor case. Excessive voltage can also be responsible for melting of the resistor, for example such as a faulty voltage regulator, mounting it without a metal heat sink, mounting it with no air flow, or mounting it in an enclosed area where excess heat is trapped. With all other models (such as those that are designed to be wired in “parallel”, i.e. KW, 475-875, 525-875, 575-875, 475-100, 525-100, 575-100, etc.) a melted resistor can be caused by a faulty voltage regulator, mounting it without a metal heat sink, mounting it with no air flow, or mounting it in an enclosed area where excess heat is trapped. Switch: The 3-position switch has a pivot mechanism inside the housing, which you cannot see. When the switch is moved to "Hi" or to "Lo" it connects the center terminal to the diagonally opposite terminal (diagonally opposite to the toggle pole). So when you move the toggle pole up, it sends the power down. When you move the toggle down, it sends the power to the upper terminal. The diagram packaged with the product is correct, even though it may look backwards. Epoxy: You must use a slow-cure type 2-part epoxy because the grips get hot, and excessive heat can break down the lower temperature quick-epoxy. J.B. Weld epoxy is fine, or Poxy-Weld Industrial Strength. Both are often found at auto parts stores, or at your local Wal-Mart store. At Wal-Mart it is in the aisle where they keep the automobile oil additives. If other brands are available to you, avoid any that discuss 5 minute cure on the packaging. Look for 250 degrees F. service duty. Voltage Source Testing: You can troubleshoot Hot Grips® most easily at first with an independent voltage source, i.e. one independent from your vehicle's electrical system. Remove center wire ( or cut it a few inches away) from the Hot Grip® 3-position switch, and use an independent voltage source. Use a car battery or a 12 volt battery charger with minimum 3 amps output to feed power to the switch. Ground the last grip's (they are wired in "series") wire to the car battery or battery charger's negative. You've bypassed any voltage source problem that may originate from the vehicle. IMPORTANT EXCEPTIONS: Honda Gold Wing, Honda Magna, Honda Valkyrie, Honda VFR800, Honda ST1100, Harley Davidson and Part #'s 475-875, 525-875, 575-875, 475-940 KW, 475-100, 525-100, 575-100, 475-ATV, 525-ATV and 575-ATV models are to be wired in "Parallel" like in their own respective instructions. Turn the Hot Grips® switch to "Hi" and the grips should heat up in 3-5 minutes. If not, then you need to check resistance of each grip, and the switch. Bypassing the switch is easy, instead of wiring your independent voltage source to the center terminal, just wire it to wire going from the switch to the first Hot Grip®. Basic Resistance Test: Most Hot Grips® have an electrical resistance of 2.4 ohms each, though YAMAHA original equipment heated grips from 1990 through 1999 are 3.0 ohms, and some street bike models (Honda Gold Wing, Honda Magna, Honda Valkyrie, Honda VFR800, Honda ST1100, Harley Davidson and Part #'s 475-875, 525-875, 575-875, 475-100, 525-100 and 575-100 models) can be in a range of 8 to 10 ohms. To test the grip's resistance, use a volt-ohm meter and set the meter to Rx1 or lowest most sensitive resistance range. Zero adjust your meter if it has that feature, by touching the two test leads together and pressing your meter's reset button or adjusting the appropriate control. If your meter has no zero adjust feature, then you must first touch the meter contacts together and make a note of the resistance value. Subtract it from your test results. Resistance Chart Grip Style ohms 000-100 series (SNOE), 000-200 series (HW-Hidden Wire), 000-300 series (SND/ATV), Part# 000-401, 520-750 Ergo I, 520-760 Ergo II and replacement grips purchased for Polaris, Bombardier and Arctic Cat. 2.4 All Honda models, Harley Davidson and Part #'s 475-875, 525-875, 575-875, 475-940 KW, 475-100, 525-100, 575-100, 475-ATV, 525-ATV and 575-ATV 7.5 - 10 All Yamaha Models Part #'s 60X-881, 60X-854 and 66X-844 3.0 3-Wire Dual Heat Part #'s 000-123 and 000-126 8.1 high, 14.4 low If the meter reading shows an open circuit, or infinity, then possibly a break has occurred where the lead wires enter the grip. This might happen if more than 20 pounds of force had been placed on the lead wires, or if you failed to use epoxy on the grips, and they rotated while riding the vehicle. If this has happened, you have two options: replace the grip, or repair it by cutting open the area where the lead wires enter the grip, and re-soldering where it broke. If the meter reading shows a closed circuit (zero ohms) then instead of breaking the connection from too much force, the two lead wires have been pulled together and are touching, electrically bypassing the grip's internal 63" of resistance wire. Your options are to replace the grip or cut open the area and separate the two lead wires or brass crimps you find inside. Some installation problems can occur when the installer selects a power source that is inadequate to power the Hot Grips®, but may be powerful enough to run a test light. Just because a wire lights up a test light, that doesn't mean it has the power to run a 30 watt accessory such as Hot Grips®, or any 30 watt load, such as a headlight. To test against this potential problem, take the same wire you are using to feed the Hot Grips® switch, and wire it to a 30 watt headlight, or to two 15 watt brake light bulbs wired in "parallel". (An exception is the Honda Gold Wing model Hot Grips®, which are 18 watts per grip, and 36 total for the pair.) If they only light up dimly, then clearly the wire chosen is not powerful enough to do the job. Your installer has chosen a wire( voltage source) that already is fully using it's available power capacity running other electrical loads. Or it could be that with your magneto electrical system, it doesn't generate a full 12 volts at a low rpm engine speed. If you do not have 12 volts at idle, then don't expect the Hot Grips® to heat up to their potential. Good Soldered Connections are important and we've found that the 3M squeeze on connections are not reliable over time for two reasons. Often there is a mismatch in the wire gauge of the Hot Grips® lead wire (20 AWG) and the 3M connector on hand. And, over time, we've observed these connectors result in oxidation of the connection, the exposed copper strands of the wire turn green with corrosion. The same problems can occur with the push together 1/4" spade connectors. Ground Connection is critical, you cannot just check with a test light bulb for continuity because your eye cannot perceive minor voltage drops. Check with a volt-ohm-meter and make sure your ground connection is zero ohms. If you have 1 ohm or more then that small resistance is contributing to poor heat output on the grips. Make sure the paint is scratched off under the ground connection. Some snowmobiles have a wired ground substitute and don't use a "frame ground". Wired Switch Backwards? Possibly your "Hi" and "Lo" heat positions are reversed. When you place the switch to the "Hi" position, it is electrically connecting the center terminal to the diagonally opposite terminal from the toggle position. This is due to a hidden pivoting mechanism inside the switch. If you installed the wires wrong, then "Hi" would be "Lo" and "Lo" would be "Hi". Wired Grips Wrong? If the instructions described wiring the grips in "series" then that means voltage goes into one grip then out to the second grip before reaching electrical ground. "Parallel" wiring would mean each grip has it's own ground wire. Most Hot Grips® are wired in "series", so each grip only effectively gets 6 volts on a 12 volt system. (Note that Honda Gold Wing and Harley Davidson specific model Hot Grips® are wired in "parallel" which means each grip will get 12 volts and have it's own ground.) If your grips were mistakenly wired in "parallel", then each is trying to work off 12 volts, which would mean the load on the electrical system would be 60 watts per grip instead of 15. (The electrical Ohm's Law rule reads: Volts x volts divided by ohms equals watts) 60 watts is far too great, and if your system could keep up with this demand, the grips would melt, but more likely your electrical system is overloaded, and this can cause problems such as blown fuses, damaged components, or poor heat output. Low Voltage at Idle: On vehicles without a battery, often the voltage at idle is much less than 12 volts, so don't expect to get normal heat from the Hot Grips® at idle. And raising the engine rpm while sitting still won't do it, since it takes several minutes of 12 volts to get the heat built up in the grips, it is not instant heat. On a non-battery system, generally the voltage is in the 5 to 8 range, not enough for the grips, and then as you ride off, the voltage goes up to 12-13 and stays there. This is the reason your headlights are dimmer when at idle. Yamaha Special Note: On some Yamaha snowmobiles the original equipment grips are fed 18 volts in series so that each grip receive 9 volts. This results in 27 watts per grip, which explains why Yamaha grips are the hottest grips on the market. If you have a 12 volt battery in the system, you still need time to build up heat in the grips, but at least the full 12 volts is available at idle or low engine speeds. Replacement Parts: Ordering just a resistor or a switch from the website is costly to you on the shipping. However Radio Shack stores have an acceptable substitute for each: Resistors: Radio Shack #271-131 cost two for $1.00 and you should use both of them wired in "series" to give you 2 ohms. Don't let them dangle by their lead wires, support them with a wire tie just like the original Hot Grip® resistor. Each Radio Shack resistor is rated at 10 watts/ 1.0 ohms/ 10% tolerance. Switches: Radio Shack #275-654 is a simple on-off-on switch, designated SPDT (single pole double throw, center off.) We hope this has been helpful in troubleshooting. It is very difficult to abuse the Hot Grips® electrically. The internal heating wires are very heavy gauge, not sensitive to voltage spikes like a light bulb, and will not break or "blow" like a fuse. In fact they can tolerate over 1500 degree temperature, and the rubber on the grips will melt long before the heating wire will fail. However the grip's do have a weak point, and that is they cannot tolerate too much force being placed on the lead wires entering the grip. They are good for 20 pounds of force, and beyond that, you can break the wire or the internal connection. Be sure you use epoxy to prevent rotation or movement of the grip, because that movement causes the wires to break. And secure the wires so they cannot be accidently caught by your hands while riding. Summary: Most common fault is wiring, either an installation error or damage to the wires where they enter the grips. Solder all connections, epoxy the grips on as instructed, and they should last long enough for the rubber to wear down, which would take years. One BMW rider reported over 50,000 miles on his motorcycle and the grips were worn smooth, but still heated up. Replacement Grips for snowmobiles and all-terrain vehicles can be purchased at on the internet website at www.hotgrips.com or call us for current price. We accept MasterCard, Visa, American Express Card or Discover Card. Specify which grip you have by model or detailed description: Models include: SNOE, HW, (in Black, Red, Blue, Purple, Green) SND-ATV in Black or Red, Street Bike original small diameter 7/8" handlebars Left or Right Grip, Harley Davidson 4.75" length 1" handlebars Left or Right Grip, Honda Gold Wing 5.75" length Left or Right Grip. Also available are 5.25" length grips for both 7/8" and 1" handlebar diameters and their respectively larger throttle sizes.