andrewhans Posted February 15, 2020 Report Share Posted February 15, 2020 Trying to get my Monsoon to power up for the first time. Harness is an Panic Wire drop on harness for the 3SGE BEAMS. Hooked up main power wire to the Starter lug and the ground to the intake manifold like instructions from PanicWire indicate. Also using their plug in accessory switch panel with acc, starter, and main power switches. ECU does not power on, no communication. Verified 12v going into pin 5 and checked continuity between pin 34/25 and the intake manifold for the ground supply. All is good on those but I'm getting no indicator light or ecu communication with laptop. Not sure where to go from here but hoping you guys have some input or ideas. Really hoping its a simple fix and not a cooked ecu or some other fault. Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 15, 2020 Report Share Posted February 15, 2020 All the ECU needs to power up is 12V on pin 5 and ground on 25 or 34. So if you are seeing no blue LED it suggests one of those is missing or the ecu is damaged. If it we me, I would remove it from the car and just power it up on the bench using a couple of test wires and a battery to isolate whether it was wiring or ECU. The ECU's are fairly rigorously tested for 24hours at very high and low temps before shipping so it would be highly unlikely to ever see one DOA... Quote Link to comment Share on other sites More sharing options...
andrewhans Posted February 15, 2020 Author Report Share Posted February 15, 2020 Thanks for the help. I removed the ecu from the car and bench checked it like you said and thankfully the ecu powered up and I have a blinking ecu. Looks like it may be trying to tell me codes or something but this is a huge step compared to what it's doing in the car. Quote Link to comment Share on other sites More sharing options...
Adamw Posted February 15, 2020 Report Share Posted February 15, 2020 Yes, it will be flashing error codes since no sensors are connected. The next step would be to plug ECU back into car loom and "backprobe" at the ECU plug by pushing a pin/neddle in through where the wire enters the connector so you can measure the actual voltage on pin 5 and 34 with everything connected up. Sometimes if you have a bad connection it will measure fine when there is no load/nothing plugged in but it will disappear as soon as you load the circuit up. Quote Link to comment Share on other sites More sharing options...
andrewhans Posted February 16, 2020 Author Report Share Posted February 16, 2020 I was also able to power up the ecu on the bench and get the computer to communicate with the ECU which gave me much relief. Is there a special tool to remove the pins? I'm really hoping that the harness isn't the problem but after getting the computer powered up and good comms with the laptop I'm almost sure its the harness Next time I'm at the shop I will unpin those and check with the harness connected and those pins out. Quote Link to comment Share on other sites More sharing options...
cj Posted February 16, 2020 Report Share Posted February 16, 2020 You can also test the wiring by loading it up with any random head light bulb you have floating around. a single low beam is 55w, so at 12V draws 4.5 amp. This is sufficient to load up a circuit as much as an ECU would but not enough to blow fuses etc. Just chop off the last few inches of headlight wiring from a junkyard car then you can plug in the wires anywhere you want to test. This gives you some rough feedback immediately just based on whether the bulb looks "normal" brightness. You can then test the easily exposed bits of wire with a volt meter. Quote Link to comment Share on other sites More sharing options...
andrewhans Posted February 16, 2020 Author Report Share Posted February 16, 2020 I like that idea alot actually. Will do more tracing and chasing wires on Monday when I'm back at the shop. Cross your fingers it's a simple/straight forward find. Quote Link to comment Share on other sites More sharing options...
andrewhans Posted February 17, 2020 Author Report Share Posted February 17, 2020 Here is the photos of the ground and power locations. Intake manifold for ground and starter lug for power EDIT: Just realized the ground point is on the throttle body side of a plastic isolated point... switching right now to check. Quote Link to comment Share on other sites More sharing options...
andrewhans Posted February 17, 2020 Author Report Share Posted February 17, 2020 Yup... the car and ECU fired right up... It's amazing what happens when the power and ground locations are in the correct spots. I'm going to go hang my head in victorious shame now. lol Thanks for the help! Quote Link to comment Share on other sites More sharing options...
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