The solution to the problem is to increase the heat transfer of the heater radiator, so that at low speeds (normal city mode) the stove works at full speed. To increase the intensity of the coolant circulation, I decided to use an electric pump from the Gazelle.
Work in stages:
1. First, remove the earth terminal from the battery. Remove the ignition module from the engine (photo 1); just remove the connector 1, unscrew the mounting bolts 2, 3 and 4, disconnect the high-voltage wire 5 from the fourth cylinder and put the module on top of the engine.
2. Carefully drain the coolant from the engine block, remembering to unscrew the cap on the expansion tank.
3. From the outlet pipe of the head of the unit (photo 2), disconnect the fluid supply hose to the heater and grow it with a hose about 15 cm long, connecting both with a piece of water pipe (I used an adapter cut from the old faucet of the stove 2108 (photo 3) and securing them with clamps.
4. To put on the L-shaped hose from the heater 2108 on the exhaust pipe of the head of the block (photo 4) (its length is about 40 cm).
5. Install the electric pump from the Gazelle with the motor down on the studs located on the side wall of the battery shelf (photo 5: side facing the rear wall of the engine compartment).
6. Put the hose from the outlet pipe of the head of the unit onto the vertical pipe of the pump (photo 6), connect the extended hose from the heater radiator to the horizontal pipe of the pump.
7. Install the button in the front panel console, the recirculation button is suitable for the icon (photo 8); on a hairpin between the left headlight and the battery - a relay with an “ear” of 30 A. A fuse in the housing of 8 … 10 A will also be required; used in 2108 in the rear PTF circuit. Perform all connections according to the diagram.
8. Pour in coolant. Reinstall the ignition module. Connect the ground terminal to the battery.
An additional recirculation button now controls the electric pump. When the ignition is turned off, the electric pump will automatically turn off. An additional relay to turn on the pump is necessary, since the current it consumes is 2.8–3 A, but not 250 mA, as they say in some articles.
The electric pump does not want to work perfectly. Antifreeze escapes from the junction of parts of the plastic case (photo 7). The reason is the gasket, it is uneven, with torn edges and other defects. Parts of the case are pulled together by four self-tapping screws, which are rotated in soft plastic. The simplest solution is: we put the gasket on the sealant, replace the screws with screws and nuts.
If there is time and desire, you can make a small hole in the upper right corner of the button for a small LED (photo 9). Soldering a resistor with a resistance of 2–5 kΩ to one of the terminals of the LED, connect the positive terminal to the contact of the button, on which +12 V appears after it is pressed, and the negative terminal to ground on the button’s backlight (see diagram).
In order to distinguish between regular and additional recirculation in the dark, you can make multi-colored interior lighting. We disassemble the button, pull out the green filter and light bulb. In place of the bulb we put the LED of the desired color with a soldered resistor of 0.8–1 kΩ, observing the polarity. In the diagram, this chain is shown in dotted lines.