First of all, this is a MS2 on a V3 board. 1976 mopar 400 with a custom throttle body. Things are running well, but have not been able to get the IAC to do anything at all. Its the GM 2x2 square connector type. I've confirmed i'm wired to the correct pins, and when i have the IAC out so i can see it and use the test for sending # of steps, etc, it doesnt move. I see in data logs that values are being recorded as IAC steps, but the thing never moves.
I'm now using the procedure here to verify the circuit:
https://www.DIYAutoTune.com/support/tec ... epper-iac/
Where i set the outputs to turn on/off based on TPS, so i can check voltage, and then move the throttle and check voltage again. I am supposed to see zero volts everywhere when they're off, and then see 12v on the A side when its on.
What i'm seeing is 12v on the A side and zero on the B when the outputs are OFF. And then just the opposite when its ON. There is always 12v at either the a side or b side.
This is just plain wrong, right? Is this indicative of a wiring issue, stepper circuit botched, or something else? This is a pre-assembled unit i bought from DIYAutoTune back in September.
thanks!
IAC wiring testing coming back just weird
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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.
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gregdeputy
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Matt Cramer
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Re: IAC wiring testing coming back just weird
Sounds like the stepper chip is working but miswired.
