Hi guys,

I would like to get this thing fixed tonight if at all possible.

Some background info. When I was hooking this up, I was one wire tap short, so I left the coolant wire unhooked. I was getting crazy readings. It ended up being a bad ground. I fixed it last night and had fine readings all day today, except for the coolant temp of course.

I went by AutoZone and picked up some more T-taps this afternoon so I could tap the coolant line. I got it all hooked up and checked the gauge readings. Everything was good and the readings were normal. So I shut it down and proceeded to wire tie everything out of the way. After I got done, I went back to check the readings one last time.

All of the gauges are reading screwey now. The pyro reads 460 with the engine off. The boost reads 46. The tranny temp reads 280. The coolant temp reads 0. They were all at the opposite ends of the spectrum yesterday with the bad ground. I changed absolutely nothing other than tying the wires up out of the way between the time that everything was working and now.

I've already checked the ground, and it should be good. It was working all day today with the ground in the same spot. I tried unhooking the coolant temp to see if that was it, but after being disconnected the coolant just read 223 and everything else was unchanged.

I'm thinking there's a short, but I'm not sure. What should I check to try and diagnose this problem?

Thanks

 

Most of the problems I have read about have been grounds, t taps and pluging into the the map sensor or rail sensor backwards. You can plug the connectors in backwards. On mine I checked to make sure the color coding matched. Most recommend dielectric grease on the conncetors.

The T taps I believe are too large for the small wires supplied. I had trouble once with the boost reading and I just doubled the wire.

Now my memory is not the best but if I recall correctly a bad ground can give you max reading with the motor off.

 

I originally had a bad ground that was giving crazy readings. I fixed that yesterday, and it was reading everything perfectly fine today (except for the coolant temp since it wasn't even tapped yet). So, I don't think it is a bad connection in the t-taps or the connectors being backwards. Otherwise it would have given bad readings today. Same thing for the ground. Why would it work all day today, after I hooked up the coolant tap but before tying the wires up, and then go crazy after tying up the wires?

Also, when the ground was bad, my readings were the opposite of what they are right now. My EGTs were a constant 32, boost was 0, tranny temp was all over the place, and coolant was 223 (it wasn't hooked up).

 

maybe when you tied it up you pulled one of the wires from the t tap?

 

Checked that also. They're all plugged in. I just checked it again to make sure. I also made sure that they were all making full contact.

I moved the ground again. It didn't change anything. I tried flipping all the connections over to make sure that I did not have anything plugged in backwards. This also did not change anything.

I tried updating the Commander to make sure that it was not a software problem. I noticed that while the commander was running off of my laptops power through the usb cable, the readings changed. They changed like it had a bad ground again. Unplug it from the laptop and run it off the truck's power, and it is back to the same crazy readings that I started tonight with. I can't think of anything else to try. I'm at a loss...

 

check the plug on the commander to make sure you didn't pull a pin from the plug.

 

I'm going to check that out when I get home today.

I sent an email to Quadzilla earlier today, but I haven't heard back from them yet. If anyone has any other suggestions, I'm all ears. Thanks.

 

I had a similar problem with my Commander. It happened out of the blue while driving. All the display parameters went loopy and some of the warning screens started flashing too. I checked the ground for continuity and it was fine (never touched it). After talking to Jeremy at Quad, he suggested that I download the latest Commander update and try it again to see if the problem goes away. At that time, I was not aware that there was an update and I thought I had the latest software version.....I did not. While I was skeptical that this would solve the problem, I took his advice and installed the update. After the update everything was back to normal and the Commander funtioned properly. So, take that for what it is worth....

Try downloading 1.4.9

Commander Update Page

 

Just got off the phone with Jeremy. We checked a lot of different things, but none of it fixed it. He mentioned that it might be something wrong with the unit itself, and that it isn't seeing the ground. He wants me to check the voltage going from where I have the ground to the pad on the circuit board where the ground wire connects. If there's no voltage, then there's a problem with the unit itself, and I'll need to send it in for repair. I'll have to do that tomorrow at work since I don't have a multimeter here.

 

I forgot to mention this last night, but I did find a wire that had come loose from the pin on one of the connectors. It was to the thermocouple though, and Jeremy said that it would only affect the thermocouple reading, not the rest of the gauges.

Now, you are NOT supposed to see voltage on the ground wire if it is functioning properly, correct?

I'm assuming the above is correct. I just got out and checked the voltage. I have 12.5V on the ground wire. So that means that it is a bad ground. That is really strange though, because I did not move the ground wire at all. So it was grounded just fine in this spot, and then poof! It's not a good spot for the ground anymore once I tied up the wires.

Where do you guys have the ground located for your Commander?

I'll try that and see what happens. If worse comes to worse, I'll extend the stupid wire and connect it to the negative terminal on the battery and see what happens.