mrryanbaker

iTrader: (11)

Wouldn't the simple fix just to be running the red wire to a switched 12v source with an inline fuse? Doesn't matter where the gauge is powered from. Realistically you're probably just going to use those three wires ever. Give that red some power, ground that black one at the MS common ground, and then feed the MS WB input that white wire. Or am I suddenly a crazy person?

ridethecliche

iTrader: (2)

You're not wrong, but the issue is that the MS was behaving unexpectedly given how it was wired.

Brain and I did some troubleshooting and the unit is going to be back to him in the morning to see what was going on. There were some spots where the voltage wasn't quite making sense and he's way better at this than I'll ever be so I'd rather not blow up the MS3 or my car!

ridethecliche

iTrader: (2)

Update: Brain fixed the issue on the megasquirt so I think that variable has been excluded.

It's still not working...

Here's what I know: the gauge unit itself will power up when connected to the battery. The display turns on, so that should be okay. Will an issue with the sensor cause the gauge to not display a reading?

This is what I tried today. I wired the wideband into the 12v source on the megasquirt. Nothing.
I then used an add-a-fuse circuit to add the wideband. Still nothing.
I switched the add-a-fuse to the radio to make sure it was working. The radio and gauges powered through the radio work, but the wideband display doesn't turn on.
On the first page, there was a brown wire that may have been a second ground. I spliced that to the main ground (black wire) for the gauge and used butt connectors to connect that to the ground off the megasquirt. Still nothing.

At most, the gauge blinks on for a split second sometimes but tit's legitimately for a split second.

I bought it used off a user here that said it was only run for an hour. I messaged him earlier to double check and see if he ever actually got it reading. I'm hoping it wasn't a bum unit.

At this point, I might just order another unit, which is going to friggin hurt... A friend is letting me borrow his wideband for the weekend and it is also an AEM unit, but one level down from the x-series. If the connectors are compatible, I'm going to try to swap head units to see if that's what's causing the issue, otherwise I might just order a new one on amazon or something so it's here early next week.

To add some icing to the cake, my battery finally died today after putting up with me for hours of this shenanigans. I tried jump starting the car to see if the wideband was giving a signal at all, and no dice.

Any advice would be appreciated. Even if it is to suck it up and dish out 175 bucks more after paying someone 150 for what may be a dud unit. I'm really hoping that's not the case but...

ridethecliche

iTrader: (2)

Update: Just heard back from the seller that it was working when he shipped it out and he sent video as well. So that's great, but now I'm even more confused haha.

ridethecliche

iTrader: (2)

And another update.

Just called aem and they walked me through a few things. Turns out the gauge is broken. I guess that explains why nothing made sense....

Seller's being a stand up gent and sent me his receipt. It was less than a year old and the unit is on its way back to AEM with an RMA. So my build is delayed yet again, but it seems like this will get fixed and only cost me the time and few dollars to ship it in.

mj1176

sorry to dig up a dead thread but did you ever figure out whether that brown signal ground wire was necessary? I'm trying to get my car running on DIYPNP with the same AEM gauge/sensor kit and the gauge powers up /reads AFR fine it's just not sending to megasquirt/tunerstudio correctly. At first I had the white signal wire going into the harness at the stock location via the single wire connector cut off the stock O2 sensor. That only gave me a flat 19.1 AFR reading in my logs for when I tried to start the car so based on some recommendations here and elsewhere I sent that white wire directly to the DIYPNP O2 input via the DB15 connector and a jumper from O2 on the main board to the corresponding pin on the DB15 port. Tried to start again and now it shows AFR fluctuations in the logs but they're still obviously not correct. All I can think of at this point is that these newer UEGO units need the brown analog negative wire to be connected to signal ground on the DIYPNP but I'm not sure.