Adrenalcookie

Hello, i have just installed a aem 30-0300 into my 1990 miata and it just goes through the heat cycle, says LS4.9 and heats up again, I have the red wire hooked up to the blue wire from the cigarette lighter, black wire to the black wire from the lighter, the white wire to the one that originally went from the narrow band to the ecu and the brown one i have grounded to a bolt on the engine block.

L337TurboZ

iTrader: (1)

I have always ran my wideband sensors directly off of switched ignition voltage. If you plan on running multiple gauges or power devices you could consider a small power distribution block mounted under the dash. You'd run just one with tied to IGN ON voltage and then have a post for each load you wanted to add. It really simplifies things. All you need to do is crimp an eyelet onto a mini fuse holder and solder it inline with the harness for the gauge.

​​​​​Same thing goes with grounds too. Get a grounding block and use that.

As for the issue it's having, if it isn't properly powered or grounded then the gauge can't properly boot up/calibrate.

Adrenalcookie

thanks for the info! First I'm going to see if it is my sensor ground, i lengthened the brown wire with a thicker wire wire since none of the stores around me had not have anything thin enough. ill see if it works if i redo it with thinner wire. others on youtube use the cig lighter power and ground with no issue so i don't believe that is the issue but if re doing the sensor ground does not fix it i will run it off the ignition and see if that fixes it.

L337TurboZ

iTrader: (1)

You can use the cigarette lighter for a power source I'm just the type of person that doesn't want to tap into existing powers/grounds if not needed. I only run two additional load circuits on my car now which is my boost gauge and AFR gauge. The block I was suggesting would be something along the lines of this