I need to modify the fuel pump drive on a V3.0 board to provide +12V on pin 37 (DB37) in lieu of the ground of the standard circuit.
This will permit me to use my car's existing wiring without modification.
I have put together a circuit which I think should work and would really appreciate confirmation from someone who knows more about electronics than I do.
Can someone confirm that this will work ?
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Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
Read the manual to see if your question is answered there before posting. If you have questions about MS1/Extra or MS2/Extra or other non-B&G code configuration or tuning, please post them at http://www.msextra.com The full forum rules are here: Forum Rules, be sure to read them all regularly.
MurrayA4,
Use the relay board. It will provide you with +12V output for fuel pump, it will protect your circuits and you will not have to modify MS electronics. As for your schematic, you should add resistor between base and emmiter terminals of PNP tranzistor in order to set the base potential when Q19 is switched off. 10K should be OK and you have to change it's base resistor from 1K down to about 270 - 330 Ohms to put the PNP tranzistor in full OPEN state when Q19 switches ON. And I think that it will be good to place one diode 1N4001 in parallel of Emmiter - Collector terminals (cathode to +12V) to protect PNP tranzistor from fuel pump's relay reverse voltage while switching ON/OFF. Hope this will help.
Use the relay board. It will provide you with +12V output for fuel pump, it will protect your circuits and you will not have to modify MS electronics. As for your schematic, you should add resistor between base and emmiter terminals of PNP tranzistor in order to set the base potential when Q19 is switched off. 10K should be OK and you have to change it's base resistor from 1K down to about 270 - 330 Ohms to put the PNP tranzistor in full OPEN state when Q19 switches ON. And I think that it will be good to place one diode 1N4001 in parallel of Emmiter - Collector terminals (cathode to +12V) to protect PNP tranzistor from fuel pump's relay reverse voltage while switching ON/OFF. Hope this will help.