newbie electrical help! - Toyota Nation Forum : Toyota Car and Truck Forums

pete3423 · 09-19-2011, 06:18 PM

hello all! new guy with a question i cant find the answer to. if anybody knows where to find the answer just point me in the right direction.

I just installed a DUAL head unit in my wife's 2003 corolla se. now the gauge illumination doesn't light up. she told me about this after a month, so i am not completely sure that the problem is related, but she did say that it hasn't worked since the install. there are 2 dimmer wires (ground, and i'm assuming power (orange) ) that did not have a connection to the head unit so i just clipped them. i have checked all the fuses and connections after taking the dash apart again (however if anyone has a fuse diagram or schedule, there isn't one in the manual and not one for the interior dash panel that i can find)
ALSO, the rear tail lights do not work either (also possibly unrelated but not sure), (brake, reverse, and blinkers all work.)

any suggestions would be appreciated

winkzoot · 09-20-2011, 10:02 AM

Here is the diagram for my 2005 XRS, but should be similar. If you do not already have a Hanes manual I would invest in one, there will be similar diagrams in it. I could check the dimmer switch pin 3 for ground and pin 6 for battery power. If those are both good I would suspect the switch. The pin out might be different so I would go to alldata.com or the Hayes manual first. The switch would explain all of the symptons you have listed including the tail lights. Hope this helped.

pete3423 · 09-22-2011, 12:28 AM

thanks for the info and the help. i don't think that diagram you posted was the correct one. I'm not sure where the switch is, so if you could help a little bit more i would appreciate it. thanks again.

winkzoot · 09-22-2011, 02:59 PM

Not sure what happened with the link for the picture, that is not what I meant to send. I each time I look at the thread I get a different picture. Remember, My corolla is an 05 so first off get a Haynes manual so that you know you are looking at the correct diagrams. Easiest thing to check (I know you said you did but make sure) the 10 A Gauge fuse is good (check it with a meter don't rely on a visual inspection). Second since your problem started when you installed the new head unit I would look to make sure that the two wires you disconnected are not exposed and touching ground in anyway. Next, the dimmer switch on the left side of the dash is what I was talking about. Lets you adjust how bright the dash lights are. I would start with it, checking the two pins I mentioned for power and ground. After that there is a combination relay that controls all the lighting behind the dash. Hope this helps.

Here are the correct pictures, I hope.

Let me know how it turns out.

Wink