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Hi friends! I wanted to get some opinions on how to wire up my gauges and radio.
Some history: My evo 8 has an AEM UEGO wideband and and AEM electronic boost gauge. To power them, I tapped into the radio harness (not the factory wires, the adapter to the aftermarket radio). I got ground from some metal behind the radio. Also, the AEM wideband signal wire was tapped into the rear o2 sensor pin on the ecu so I can log it.
For the most part, this worked fine. At some point, the wideband gauge would start improperly and would end up reading 0 while the car was idling. I vaguely remember reading something about this and determined that it was wired incorrectly. This wasn't a big deal. Next my aftermarket radio started acting up. It would not respond to the controls on the faceplate. I read that my particular model has this issue and many users often complained of this. The cause being bad or dirty contacts between the radio and faceplate. Next I started experiencing an issue where the ecu fuse started blowing (Thread here).
Unfortunately other things have taken priority and I haven't had much time to work on the car, but I want to start with a couple items that I've wanted to do anyway. I was never really happy with my wiring of all of this, so I wanted to clean it up and now is the time to do it. Part of that list is to wire the gauges better, and thus begins my question...
I don't want to tap into the radio's wiring harness for the gauges. I don't think it is clean and I think it is possible to maybe overload the circuit. Either way, I'd like to find a different power source. I like the idea of these pigtail fuses (link), but I'm not 100% sure how I should go about using them. I have some questions:
1) Should I be using these in an empty fuse location in the fuse box?
2) Where should I use these to get constant 12v and where should I use this to get acc power?
3) Where should these get grounded?
Full disclaimer, I'm very ignorant when it comes to wiring and electronics, so I wanted to get some opinions here and try to do things correctly. I was fortunate enough that a friend of mine taught me a little soldering. I plan to connect the wires by bending each end into a "U" shape and hooking them together, then soldering them, then heat shrink over top. It is my understanding that this should create a reliable connection.
Again, any and all advise is welcome. Thank you for being such an awesome community!
Fuse taps are IMO more appropriate for temporary installs. When ever you add a new circuit to your car though you will want to also add a fuse holder as close to the power source as possible. So if you tap a power wire, you will want a fuse holder and fuse as close to that as possible. You will want to properly tap your harness like this picture (this is milspec which is kind of overkill, but some variation of this splitting inserting and twisting will be good):
Where you decide to tap in all depends on the location of your gauges. You want to keep all your wires as short as possible. This will keep everything clean, make routing easier, reduce complexity, and weight.
For example I too have my wideband controller wired into my rear 02 sensor for logging. So i mounted the controller next to the ECU to keep all the wires as short as possible. After verifying the circuit had enough head room to handle the current, I tapped the switched 12v on the ecu harness for power and added a fuse. This kept the wire short and also made sure my voltage reference between the ecu and controller was the same for accuracy sake. I also grounded the controller at the same chassis point as the ecu. So if your gauges are near your radio harness, and you can even tap the harness adapter and not even touch your factory wires, that would be a good choice.
1) I like the recommendation for tapping a wire, I never thought of doing it that way!
2) The gauges were already tapped into the radio harness. The factor wires are unscathed.
3) The control for the o2 sensor I believe is under the car because of how short the wiring was between that and the o2 sensor. Perhaps I should extend the wires and mount the controller inside. It's been a while since I've been under the car, so I would have to confirm. Regardless, I am not happy with how I routed the wiring for the o2 sensor. The wiring runs from the exhaust location to the driver's side through the fender and into the cabin. It's not clean and is a poor location. Where did you route your wiring into the cabin?
Because I also have my wideband controller doing narrowband simulation for the front 02 sensor, I placed the wideband very close to the turbo on my downpipe (16" from the turbine outlet) so my routing is probably not appropriate for typical wideband sensor location (in front of the cat). I would say going through the factory location for the rear 02 sensor grommet is probably the best way to route it. Its been a real long time since i wired that sensor up though so I would have to go get under the car to see the exact route I used.
I don't know about your controller specifically, but they have pretty sensitive electronics inside them, and i know mine certainly isn't packaged to handle exposure to the elements and the extreme environment of being under a car.
I soldered together the wiring harness for my new radio and went to install it last night. Unfortunately, somehow I managed to rip the acc 12v wire out of the pin in the connector that goes into the radio! D'oh! Does anyone know how I can repair this? Is it repairable???
I soldered together the wiring harness for my new radio and went to install it last night. Unfortunately, somehow I managed to rip the acc 12v wire out of the pin in the connector that goes into the radio! D'oh! Does anyone know how I can repair this? Is it repairable???
You should be able to just push it back in and it will lock. If it doesn't, you will need to try and get a super tiny flat head or a pick in there and bend back the locking tab.
The wire itself was pulled from the pin. The pin is still inside the connector. I guess I have to push the pin back out. Can it be re-crimped? Or would I need to find a new pin to crimp on to the wire?
May 12, 2017, 08:59 AM
