Aftermarket Head Unit Install - No Gauge Lights

I spent the last two days searching here and other sites and can't figure out how to fix an issue I have. I'll try to provide as much detail as possible:

I have a 2010 Double Cab Sport with standard (Non JBL) Stereo. Two months after I bought the truck, I bought and installed an aftermarket kenwood head unit. During the install, I connected the Dimmer Ground and ran into all the problems that went with it, including blowing a fuse and losing the gauge lights.. After researching and a little trial and error, I figured out that fixing it was as easy as just disconnecting the dimmer grounding wire. All was good for the last year and a half, but of course, I decided it was time to do another upgrade.

Thursday, I put in a Kenwood DNX-9980HD Nav, Double Din unit. I bought it from Crutchfield and it came with the adapter and wiring, so rather than using the old harness, I used the new one. Interestingly enough, the new one had no dimmer ground wire.

As a side note, I have the SWI-Jack from Pac so I can use the steering wheel controls.

Installed everything and the head unit works great, but I have no Gauge lights again. Here's what I have done to troubleshoot:

1. Checked all fuses, both behind the dash and under the hood. Pulled each individually and verified none are tripped.
2. Verified all the other dash lights work and that they dim with the dimmer, so it is not the reostat.
3. Tried old aftermarket radio with the old harness, no change.
4. Verified that the new harness wires and old harness wires are exactly the same (minus the dimmer ground on the new one)
5. Checked the dimmer relay.

I even talked to a Toyota tech who was lost for ideas, other than to check with a local radio installer.

Hoping maybe someone else ran into this or has some suggestions?

Thanks for the help!

 

i am clueless man. Are you positive you have your dimmer turned all the way up? I just hooked one up in mine and even used the dimmer wire and have no issue. Knock on wood.

 

Unfortunately, not so easy. That was the first thing I tried. The weird part is that all lights work on the dash, dimming included, other than the gauge lights. It would seem a faulty wire being grounded or such, but I definitely have no exposed wires.

 

I have issues with this too. I hooked up the dimmer ground to the black wires and i connected the dimmer wire from the truck to the dimmer wire on the hu. Now I can't dim my speedo cluster....? The deck goes from day to night when the lights are switched on as it should. I think i am going to cut out all the dimmer wires and be done with it.

 

this is exactly how mine is since I installed my unit, I've never bother looking in to it since I never dim my cluster, but would be nice to know what it is.

declan, although the other lights on the dash dim with the rheostat I think it could still be the rheostat, maybe you could look into it and bypass it to completely rule it out.

 

I cut both dimmer wires out and everything works fine again. I just used the time of day function to dim the HU. Works for me.

 

Took some time to look at this again yesterday. Initially, I was going to remove the Rheostat/Dimmer Switch and jump it, but when I got it out, it was five wires, not two.

Before giving in and buying a new Rheostat at 140.00 plus tax, I decided to look into the harness. The harness I had did NOT have a dimmer ground, although it's mentioned in many posts here. I had the Scosche harness and dash kit.

Went to the local radio shop and talked to him. He actually hadn't dealt much with Tacomas, but he did have the Metra kit, which has the dimmer ground. Spent the 30 minutes re-wiring the entire harness, hooking the dimmer wire into the ground. I left the other dimmer wire (non ground) disconnected.

Hooked it all up and now I have gauge lights. Dimmer works for everything else. My Gauge lights are always on and I'm not sure if that is the factory default or not, but I'm okay with it. Looks like all is functioning as it should.

As a side note, I talked to a Toyota tech at the local dealership and he said that he has never heard of a Rheostat being burned out, but still work to dim the dash lights. He said nothing is outside the realm of possibility, but his comment was that if it works at all, usually it's not the issue. Now, I'm not saying others that described the same problem as me didn't have an issue with the Rheostat, but passing along what I was told.

I guess my only other question needs to go to Toyota: Why the hell did you ground the gauge lights through the radio harness?

 

I had the dimmer ground connected to ground and the dimmer wire connected to the dimmer wire in the harness and it effed with my ability to dim my spedo cluster. I do a lot of long trips so that is a crucial function for me. Like I said, it was just easier to cut anything with dimmer on it and take it out of the mix completely. I just use the time dimmer function on the HU. I like it better since sometimes I drive with my lights on and don't way the HU dimmed.

 

So you cut the ground wire too? When I cut the ground dimmer wire, I lost lights on the cluster. Right now, I have the dimmer ground wired, but the dimmer left cut. It's the only way to get light on the cluster. I do not have dim capability. I was thinking I need to just hook up the dimmer wire and see if that works.

It's weird, because I've read and seen so many different ways that people get it to work. I'm wondering if it's different wiring based on cab, year or model. In any case, it's a big pain the butt.

 

this is a big pain. I will have to take the head unit apart again.

 

I just found that I am blowing a fuse in the under dash pannel. It is the illuminate fuse so I will try to ground my illuminate wire and see if that helps.

 

I figured it out! so I took the HU back out and tested the orange wire on the truck side of the connector. Found that it was 12v+. So after reading a few other things I saw that someone said there was an open ground? Hmm if you dont complete the circuit it will burn out the fuse. (Which i went through 3 fuses) so figured it couldnt hurt if I placed a light between the orange wire and ground. It worked! so I few weeks ago i did the cupholder led mod. so wired it up and i have all my dash lights again. let me know if anyone has questions

 

I am Interested in what you did. What did you doe with the Dimmer (orange) and the Dimmer ground (orange/black)?