For installation of an MS, I need to reverse the fuel pump control signal that MS puts out. MS grounds a signal to command the fuel pump to run. My car's fuel pump circuit -- at the particular control wire that I want to use -- requires an open circuit to run the pump with a ground to shut the pump off.
I can do this with a mechanical relay but am looking for that little elegant circuit that will perform the same function. The circuit would take the MS fuel pump signal as input and operate on the OEM pump control wire -- open circuit run and grounding to shut off.
Does anyone have a schematic for a circuit to accomplish this?
Brian
Chester, VA
Reversing MS fuel pump control signal
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Read the manual to see if your question is answered there before posting. Many users will not reply if the answer is already available in the manual.
If your question is about troubleshooting, configuration, or tuning, you MUST include your processor type (MS-I or MS-II) and code version in your post. If your question is about PCB assembly or modifications, you must also include the main board version number (1.01, 2.2 or 3.0).
If you have questions about MS1/Extra or MS2/Extra code configuration or tuning, please post them at www.msextra.com Such questions posted here will be moved to: a temporary MSextra sub-forum, where they will be removed after 7 days
The full forum rules are here: Forum Rules, be sure to read them all regularly.
Re: Reversing MS fuel pump control signal
what is wrong with a relay? MS can't handle the current that a fuel pump draws directly. You may want to test and see how much current the fuel pump trigger wire draws. A relay would be your best bet.
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Re: Reversing MS fuel pump control signal
A relay would work, for sure. But a circuit would be more elegant -- and sometimes that counts.
The OEM control wire I speak of comes from the fuel pump relay terminal 85. When you ground that terminal, it shuts the fuel pump off. So the circuit would not be handling fuel pump loads.
I hear tell that a triac might be just the trick. But I do not know how to make that work.
The OEM control wire I speak of comes from the fuel pump relay terminal 85. When you ground that terminal, it shuts the fuel pump off. So the circuit would not be handling fuel pump loads.
I hear tell that a triac might be just the trick. But I do not know how to make that work.