Russian Motorcycle Turn-Signals 01/11 Ernie Franke (eafranke@tampabay.rr.
What's the most fragile, yet inexpensive, part in your Russian motorcycle? -the engine, -the alternator, - or the owner? This part hasn't always been around. In fact even today, less than half the States require them. It's your Turn-Signals! Let's take a good look at turn-signals for Russian motorcycles over the last fifty years. The subject surfaces in forums when folks try to trouble-shoot the circuit or try to substitute Light-Emitting Diodes (LEDs) for the incandescent bulbs. We'll trace the history of turn-signals, understand the function of the flasher unit, go thru the circuitry, trouble-shoot the problems, and understand the compatibility with LEDs. We no longer have to fear what's in that little can called the flasher unit. We'll also look at a little circuit to audibly remind you to disengage the blinker after executing a turn. So let's enter the exciting world of flasher relays. Many people have been held back, but now the truth is finally exposed. We'll find that like everything else, turn-signals are becoming solid-state. Please open the attached PowerPoint PDF presentation entitled "Russian Flasher Relays" for greater detail. Also included are replies containing Ural and Dnepr schematics with flasher circuitry.
We'll take a look at the unusual device called a thermal flasher that makes your turn-signals flash. Later we will see the electronic (electro-mechanical) flasher and see some of its advantages. Inside the thermal flasher unit is a bi-metal strip that will bend when heated. It is mounted in such a manner as to snap suddenly (and loudly) when heated or allowed to cool. As the current flows through the bi-metal strip, the strip heats up and momentarily disconnects the power flow to the signal lights. This causes the signal bulbs to go out. As the strip cools it bridges the connectors and re-lights the bulbs. This happens about one time per second, thus enabling the necessary blinking action of the turn signals which alerts the other drivers of your intentions. Thermal flasher come in 2-prong (terminal) and 3-prong configurations. All flasher units on Russian motorcycles up to 2006 were 2-prong thermal flashers. Let's see how turn-signals are wired.
When the directional turn switch is operated, a circuit exists between the battery, flasher unit and turn-signal lights back to the battery. When you push the handlebar turn-signal switch left-or-right, the thermal flasher connects to the turn-signal bulbs. This completes the circuit, allowing current to flow. Initially, the spring steel does not touch the contact, so the only thing that draws power is the resistor inside the flasher unit. Current flows through the resistive wire, heating up the smaller piece of spring steel of the bi-metal strip and then continuing on to the turn-signal lights. At this point, the current is so small that the lights won't even glow dimly. After less than a second, the small piece of spring steel heats up enough that it expands and straightens out the larger, curved piece of spring steel. This forces the curved spring steel into the contact so that current flows to the signal lights unimpeded by the resistor. With almost no current passing through the resistor, the spring steel quickly cools, bending back away from the contact and breaking the circuit. The cycle then starts over. This happens at a rate of one to two times per second (60 to 120 cycles per minute).
As a result the sneak path current will start to be equal to the primary circuit current.com) compiled a list of replacement parts. then the flasher unit is in good operating condition.2-Watt) Instrument Lights (speedometer face): Sylvania 3893 (4-Watt vs. c.com/) "1156-A30 ". Replacement Parts (Lamps and Flasher Relays) The replacement for the 12-Volt turn-signal light is the 1156 (12. Since the resistance of the two signal lamps on either side are wired in parallel. Jack Loganbill (http://www. Safe motorcycle drivers want to maintain and use their turn-signals. rated at 32 CandlePower light intensity). and other Sidecar Lights: 1156 Running Light: 97 (5-Watt) Rear sidecar running/brake light: 1157 (double-contact) Indicator Lights (high beam. the current is only 0.8-Watt. Thermal 3-Prong Flasher The thermal flasher only works properly when it is driving two 1156 turn-signal bulbs in parallel. but the un-selected side will appear almost as bright.63-Amp/16. or the pilot lamp doesn't flash. The indicator lamp is more than capable of passing the load current to both of the non-selected LED turn-signal lamps. At your local auto parts store ask for an electronic 2-prong turn-signal flasher for a GM product.4Volt/2. The commonly available 6-Volt light for older Russian motorcycles is the 1129 (6. it's the safety issue that is most important.) Connect a grounded test lamp to the "P" terminal on the flasher unit. For example. Bike Turn-Signal. neutral and turn): Sylvania 2721 (1.8-Volt/2. do the following: a. twenty times larger than that of a single 1156 turn bulb.2 end. With power and load connected. This yields a resistance of about 106-ohms. You'll probably have a hard time . the flasher unit should commence clicking loudly on/off about one cycle per second. Thus the indicator-light seriously limits the current flow in the "sneak path" and the non-selected turn-signal incandescent lights don't glow. and the lamps will get hot with about 10 watts of heat each (50% on/off duty cycle). rated at 21 Candle-Power) which also uses the same BA15S Single-Contact (SC) bayonet base. then the unit is considered trash and needs replacement. The selected turn-lights will glow brighter. 2-terminal flasher will work.12-A. and the test lamp also flashes.thewoodshop.20m. if you were to replace each of your 1156 turn-signal bulbs with SuperBright LEDs (http://www. Thus the primary circuit present a 53-ohm path (two LEDs in parallel) and the sneak path will be 181-ohms (128Ω + 53Ω). but they consume power and defeat the whole concept of using LEDs to conserve power. 3-Watt) Turn-Signal Indicator and the "Sneak Path" (please see PPT attachment0 For the blinker circuit in my 2003 Ural Patrol. If the flasher unit doesn't click at the right rate. The lamps should flash.) Connect a hot wire (12-Volts) to the "X or B" terminal of the flasher unit. The solution is to use steering diodes to ensure that the sneak path is prevented. b. the current going thru the "sneak path. Just about any 12-Volt. Under these conditions the current in the sneak path will be about one-third the current in the primary path." thru the indicator lamp. To test the thermal flasher unit. They cost about $8. is less than that of the primary path by a factor of forty. so now you have 4-way flashers instead of turn-signals. If it clicks at about the right rate.superbrightleds. the on-resistance of each 1156 bulb is 6 Ω (ohms) and the indicator lamp is 136-ohms. there will be trouble because LEDs draw much less current.1-Amp/27-Watt. Now if someone replaces all the turn-signals with LEDs. alternator. Turn the bars hard left and look behind the right fork.) Connect the load lamps between the "L" terminal and ground (return to the earth terminal of the power supply or battery). Brake Lights. Some folks suggest using load resistors (also called load equalizers) wired in parallel with each LED to simulate the incandescent bulbs. Upgrading Your Old Thermal Flasher to a New Electronic Unit The Russian Flasher unit supplied on the bikes is a thermal type.
The best way to correct the flash rate on any motorcycle is to replace the thermal factory flasher relay with one that does not have a minimum load requirement and/or bulb-out notification. The circuitry in all Dneprs and pre-2006 Urals use a single turn-indicator (instead of separate left and right indicators). 1. coming on without blinking. The canister does not need to be grounded. and the other two terminals are functionally interchangeable. or not coming on at all. going to the dashboard yellow turn-indicator light. "L" for Load or Lamps. and that is the current is radically reduced from the stock incandescent bulbs. Tridon's EL12 being two-prong and EL13. .3 finding a flasher with that style of mount other than the original. Turn signals (prior to 2006) must have ground continuity to the frame. Thus if a bulb filament blows out the flash rate won't change to indicate the fault. If it doesn't come on at all. Light Emitting Diodes (LEDs) for Turn-Signals A bulb has a lot of drawbacks. Check for bad ground in both housings. which is not the case. No turn-signals light on either side: Check the fuse. Check the flasher by substitution. 3. The good news is that all of these symptoms point to only four possible issues. a dead bulb or a corroded ground path. A wire-tie will hold the new flasher in place. "X or B" for Battery or Input Power. This means that you will need two blocking diodes up there to allow LED operation. The "P" terminal. while activating the turn signal switch. Usually. such as the Tridon 550. short circuit or poor ground. They also have heat issues if they're mounted inside or near anything that's prone to melt. a bad turn-signal flasher relay. The main attraction is also the main problem in substituting LEDs.This is actually the designed response of the flasher relay as it is trying to indicate to the operator that a bulb is burned out. 2. you have a bulb out or corroded ground or socket on that side. If the lights illuminate. Turn-signals light. This will keep the small current from flowing thru a "sneak path" (see PPT attachment). It sits in a socket that is prone to corrosion.on the flasher. You can test the turn lamps and wiring (with the key ON) by shorting across the two terminals of the flasher. Remove the old flasher by bending the mounting ears straight out and pull toward you. The filaments are always at the mercy of vibration. but will not flash it. Check for open circuit. but it does need to have the correct electrical load to operate properly. If your turn signals have stopped working. The rubber grommets are just the way the old flasher is mounted to the bike. then remove the aluminum strip from the flasher that forms its legs. it'll be doing one of these things: blinking rapidly. Some relays.the stock flasher relay begins to blink too fast. Both turn signals on one side don't work: Check for bad bulbs. Hook it up and it should work. You can use the 3-prong flasher in an older Russian bike. It is fragile by nature. are made for trailering and flashes independent of the circuit load. Your signal flashers either work or they don't. and "P" for Panel (dash indicator lamp). Modern (Urals 2006+) wiring adds a ground-return wire from each bulb to solve that problem. you'll need to replace your turn-signal flasher relay. as there is no + or . The electronic flasher will work at a constant rate of speed no matter what the motors speed. switch leads and see if it works better one way than the other. When the flasher fails it will usually light the turn signal indicator instrument panel. just ignore the "P" terminal. Under $10 at most auto stores. are load-independent and about the same size as the old Russian flasher. etc. Then remove the old Ural flasher and carefully remove the mounting bracket from the old flasher. or doesn't blink. If the signal blinks really fast. then the flasher unit is most likely bad. and they are relatively inexpensive. a dirty directional turn-signal switch. Your turn-signal relay is easy to replace. but do not flash: Replace the flasher. when you remove incandescent bulbs from a blinker system and replace them with LEDs . The 3-prong thermal or electronic flasher unit has three terminals. You want a "heavy duty" flasher meant for trailering. the three-prong. will be open circuit at rest. Trouble-Shooting Your Turn-Signal Turn-signals are one of the easiest systems in your motorcycle to trouble-shoot. You will have to crimp ¼" female spade connectors on the two wires to replace the round terminals but that's easily done. This "bulb-out" function is in the federal code for US cars since 1970.
Check the dash indicator light. Check the flasher by substitution. Indicator light doesn't work in either direction: Check If the turn signals are working. All the others lights are wired correctly with the outer shell grounded. Turn-signal flashes too fast or too slow: Check any bulb on the side flashing too fast. A heavy-duty bulb is probably installed In place of a regular bulb. A standard bulb was probably installed in place of a heavy-duty bulb. Fuses In the 2002-2005 schematic (please open attached PowerPoint presentation). It sounds much like the warning signal of a fork-lift backing up. going at 55 mph.4 4. or see the turn-indicator in full sunlight. the roar (industrial sewing machine) of the engine (or gears) make it hard to hear the rhythmic clicking of the flasher relay. . there is an in-line fuse inside the headlight cavity. Ivan's Crazy Tail-Light Wiring Several folks have replaced the rear brake and tail lights on the bike with a 1156-equivalent LEDs. but not as annoying as seeing a motorcycle tooling along with a "stuck" turn-signal. Check the bulb flashing too slow. do not require any cutting of the factory wiring to the leads going to the yellow Turn-Indicator lamp socket. You could replace just the "sockets" or replace the whole tail-light and then use LEDs. Clean contacts. but is the "hot" 12-Volt side. from your local Auto Parts Suppy. Simple tap connectors. Audible Reminder to Cancel the Turn-Signals Without a windshield. It's annoying. One turn-signal light on one side doesn't work: Check and/or replace bulb. Check for poor ground at socket. we see that the flasher fuse has been moved to the common fuse block. 5. Check for corrosion in socket. Unfortunately the outside portion of the socket is not grounded. In the 2006-2007 schematic. We added a piezo buzzer (piezo-electric transducer + oscillator circuit in plastic enclosure) to provide an audio (3 kHz) signal that beeps in accordance with the turn-signals (see attached PPT slides). Check for loose connections or corrosion at the bulb socket 6. wearing a padded helmet.