if yer gonna get that nit picky.. better go add diodes to the start solenoid and all the other relay's burried under the tractor dash.. ( IMHO.. not needed.. )
soundguy
Nitpicky? huh? here is a good link, towards the bottom this exact relay is shown and discussed, a lot of good information here:
Relays
and here is a quote from that page:
Quenching Diodes:
Anytime that a relay coil is driven by a circuit that is not specifically designed to drive a relay, you should use a quenching/suppression diode connected in parallel with the relay coil. The diagram below will show the connection of the diode. Initially, you may think the diode serves no purpose because the voltage applied to the relay cannot pass through the diode. This is true when the relay is energized. The diode comes into play when the power source is removed from the relay coil. When power is applied to the relay coil, a magnetic field is created and energy is stored in the coil. When power is removed, the magnetic field collapses causing a reverse voltage to be generated (it's called inductive kickback or back EMF). The back EMF can
easily reach 200 volts. The diode will absorb the reverse voltage spike. This voltage, if not absorbed by the diode, will cause premature failure of switch contacts and may cause the failure of power switching transistors. You can use virtually any type of rectifier or switching diode (i.e. 1N4001, 1N4002, 1N400x... or Radio Shack part #s 276-1101, 276-1102, 276-1103, 276-1104).
And lets see, I have only been working professionally in Electronics for about 38 years, and as a hobby for over 45.. hum... Now in my simple tractor, and probably yours, there probably are no microprocessors, but in a lot of newer tractors there are some. Now if you don't want to add a 59 cent diode to a relay coil, its up to you. But I just wanted to let the folks know there is some danger. IMHO:laughing::laughing:
James K0UA