Hello forum members,
I would like to add a relay circuit to my car for auxiliary coolant pump. Currently pump is controlled by the AC control unit (AAC) without a relay. This pump known to seize and sometimes burns the circuit board of the AAC which is expensive. I would like to use the AAC as the signal to the relay and feed the pump from the battery nearby. I was told to place a protective (freewheeling) diode as well so that when the AAC stops the pump, there won't be a surge from the relay coil (I am a newbie and not sure what I am talking about here..)
Please comment about my circuit below. Is the diode placed correctly? 14 V is the battery supply. Since this pump runs when the engine is running, voltage is approx 14 V due to charging. Can this extra 2V harm the pump? Pump also runs for 5 mins after the engine is off and at that time battery voltage is 12v.
12 V on the left side is going to be my signal from the AC control unit.
http://lushprojects.com/circuitjs/circuitjs.html?cct=$+1+0.000005+10.200277308269968+50+5+50 178+544+320+688+320+0+1+0.2+0+0.05+1000000+0.02+20 g+384+432+384+448+0 R+544+320+544+256+0+0+40+14+0+0+0.5 r+544+368+544+432+0+500 w+768+240+768+336+0 g+608+240+608+256+0 181+688+336+768+336+0+1840.5922678055792+30+12+0.4+0.4 w+512+432+544+432+0 w+512+352+544+352+0 w+608+240+768+240+0 w+384+432+512+432+0 w+480+352+512+352+0 s+320+352+384+352+0+1+false R+320+352+320+432+0+0+40+12+0+0+0.5 d+384+352+480+352+1+0.805904783
I would like to add a relay circuit to my car for auxiliary coolant pump. Currently pump is controlled by the AC control unit (AAC) without a relay. This pump known to seize and sometimes burns the circuit board of the AAC which is expensive. I would like to use the AAC as the signal to the relay and feed the pump from the battery nearby. I was told to place a protective (freewheeling) diode as well so that when the AAC stops the pump, there won't be a surge from the relay coil (I am a newbie and not sure what I am talking about here..)
Please comment about my circuit below. Is the diode placed correctly? 14 V is the battery supply. Since this pump runs when the engine is running, voltage is approx 14 V due to charging. Can this extra 2V harm the pump? Pump also runs for 5 mins after the engine is off and at that time battery voltage is 12v.
12 V on the left side is going to be my signal from the AC control unit.
http://lushprojects.com/circuitjs/circuitjs.html?cct=$+1+0.000005+10.200277308269968+50+5+50 178+544+320+688+320+0+1+0.2+0+0.05+1000000+0.02+20 g+384+432+384+448+0 R+544+320+544+256+0+0+40+14+0+0+0.5 r+544+368+544+432+0+500 w+768+240+768+336+0 g+608+240+608+256+0 181+688+336+768+336+0+1840.5922678055792+30+12+0.4+0.4 w+512+432+544+432+0 w+512+352+544+352+0 w+608+240+768+240+0 w+384+432+512+432+0 w+480+352+512+352+0 s+320+352+384+352+0+1+false R+320+352+320+432+0+0+40+12+0+0+0.5 d+384+352+480+352+1+0.805904783