I installed a new aftermarket radio in my 99 i30 (this forum seemed more relevant, sorry if it's the wrong one. Same car...) and I'm having a few illumination problems. I have two, one is that some of the interior lights do not turn on. Two is that all interior lights seem dim. The most obvious ones are the hazard/defrost lights, and the auto/econ/off buttons of the climate control, all of which do not turn on. I don't remember if the heated seats were illuminated, but they do not light. If you activate these buttons, their associated functions commence, and light up if they have such a light to indicate they're on.

I can't figure out what's wrong. I've been mulling over the circuit diagrams for hours. I checked each connection wire-for-wire and pin-for-pin between the FSM, the harness adapter, and the radio, and everything matched up.

I can't find a reason on the diagram that certain lights on this circuit work, namely the door locks and the radio illumination, but the hazard/defrost/climate control do not.

The second problem is the dim lights. It's been a week since I drove the car, so maybe I don't remember... but the passenger mentioned that they looked dim. The dimmer switch is functional. All of the exterior lights work.

Is there a way to check the dimmer switch with an ohm meter? I checked it and i couldn't get it to change the resistances. It's certainly a common component that could make things seem dim. Either that or the body grounds, m13/m73/m111. I jumped pins 2 and 3 on the dimmer switch but this did not change the brightness of the lights. It should have bypassed it?

Or the lighting switch? If it's burned out, the lights might be dimmer than usual? Is there an ohm reading I can get from that to check it? Something comes to mind is to check the resistance between pins 11 and 12.

I'm wondering if the voltage on the illumination lights is low, and it's below the power-up voltage of the bulbs in those elements, but sufficient for the lights which do turn on.

The grounds for the radio were grounded against the radio mounting brackets and the orange illumination wire from the radio went to the positive end of the light circuit (pin 8.) The radio dims with the lights. Battery voltage is 13.0v immediately after shut down and 13.8v with engine running. I got 12.0 volts directly at the dimmer switch.

I'm thinking at this point I need to follow the voltage across every wire and component, and look for voltage drops across each, and also check each light directly with a 12.6v source and see how they light up.

I see the circuit taking the following route:

Battery
Fusible link box (15a 66)
Lighting switch (pins 11 and 12)
Fuse box (7.5a 18)
Lamps
Illumination control switch
Grounds m13/m73/m111

Anyway, that's where I'm at. Has anybody run into this problem or have any ideas for me to pursue?

 

I would assume you have checked all possible fuses? Im sure if there was a short you would have popped a fuse or 2 aswell otherwise check to make sure you didn't accidently unplug a wire or harness somewhere if you've already checked continuity.

 

If this problem showed up after you changed the radio, I doubt that the chassis grounds have anything to do with the problem. It would more likely be something to do with the radio installation.

If you unplug the radio connectors, what do the lights do?

There are 3 wires for the dash lights. A specific light only uses 2 of the 3.
One of the wires is the 12 volts coming from fuse # 18.
The other 2 wires are related to ground.
There is a "hard" ground that is used on the few lights that do not dim.
The other is a "soft" ground created by the dimmer switch that is used by most of the lights. The soft ground is essentially a variable resistance between the light bulb and chassis ground. This wire is a red/yellow stripe wire.

You have to connect a wire to the radio to light up the display, but in many aftermarket radios, the display does not dim. The display is grounded internally in the radio. The dash light power wire that comes from the light switch to the radio, red/blue stripe, is for this purpose. The "soft" ground from the dimmer switch (red/yellow stripe) is not used.

I would double check that you did not hook up the red/yellow stripe to the illumination pin of the radio.

 

I checked the relevant fuses. Everything in question, dim and dark, comes from the same pair of fuses. I can't see how some would be dim and others dark. I'm going to light up the system and follow the voltage drops across every component, such as the fuses, to see if there's any drops in voltage, showing a marginal connection. With the radio there was an unused connection. It had three while the aftermarket harness only had two. And as far as the wiring diagram goes, the radio only needed two. I wonder if that third connection is for non Bose systems and they just gave the plug a place to go? Regardless the lights are in parallel so for example if you unplugged the radio only it would lose it's illumination while the rest would still have it. Dim lights and dark lights on the same circuit? Seems like something is marginal here and it's enough to off some lights but only dim others.

 

I know for a fact I wired the radio dimmer to the power side and not the ground side. It dims with the headlights. (I have a reference picture showing the proper connection). If wired incorrectly I am under the impression it just wouldn't dim since it would be a ground connection. The radio is looking for that 12v to tell it to dim.

 

I remember when I installed a aftermarket radio, when I got my car back the A/C..heater would would not turn On and I told them to fix it cause I can't go without A/C in hot weather and as well as cold weather for heater.

So they fixed 15 mins later it by a simple wire disconnected behind the radio. He's gotta make sure that all the fuses are connected, if he skips one or puts it incorrectly it can cause alot of things to go wrong

 

Some updates. I realized some differences in the electrical system with the i30 compared to the maxima, so I got an I30 manual and got back to it. Checked the battery voltage with the parking lights on, 12.5v. That's my reference.

First I pulled the center vent and checked the voltage on pins 5 and 6 of the defroster illumination. It read 11v. Most interesting. 11v would certainly make the interior dim. I took it a step further and pulled the defroster button from the trim and then disassembled the button, to access the bulbs. The defroster-on bulb had continuity, while the illumination one did not. Interesting. Maybe there was a spike that fried them?

But before I fret over some tiny bulbs, I needed to pursue this 11v interior light voltage. I pulled the light combination switch from the steering column and tried to diagnose it. This is when I noticed the difference in the electrical system. The I30 is better where it routes illumination through the rear brake light relay, and NOT the combination light switch. I confirmed the light switch as okay anyway by jumping pins 5 and 11, simulating setting the lights on. No change in the defroster voltage.

So then I moved to the brake light relay. I checked the input voltage on it against the combination switch ground, and got 12.5v. (this is to avoid erroneous readings with dirty engine grounds) I tried to bypass the relay and jump it, but the paper clip started heating up so I pulled that. There's another way. I installed the relay and moved to the driver fuse box. I pulled the illumination relay and check the voltage against clean interior chassis. 11v!

I'm getting a 1.5v drop across either the relay or the harness between the relay and the fuse box. I installed a replacement relay and it did not increase the voltage. This means the problem is the wiring harness between the fuse boxes. That's a long stretch of wire, but there's one last connection which connects the engine bay harness with the interior harness. I'll check that connection and update.

 

I don't understand why you're going through all of this troubleshooting. Assuming your car was perfect before the aftermarket radio was installed, you either a)installed it wrong or b) have a radio that is causing the anomalies.

Did you wire the radio the old fashioned way but cutting off the OEM connector and hard wiring everything? or did you use a harness so that everything is plug n play? If a harness, what brand harness?

 

It is unlikely but possible something broke while the car sat a week while a waited for a metra harness. The battery did die while it sat and needed to be replaced. It was on the way out. I was very exact in making sure the harness was wired properly. No harness splices so no changes to the car's electrical system.

Regardless of the setup, the voltage is low to the inside lighting. 11v is equivalent to a near dead battery, very dim. I'm just following the voltage drop. It's fine at the relay and low at the fuse, so the problem is between. This has unpowered the lighting system and thus any "weird wiring" is a non issue because it was bypassed.

Once the voltage is normal I can more accurately troubleshoot the lights. When something electrical doesn't work, you:

1: Check if it has power. If so...
2: Check/replace the part. If not...
3: Check the controls

I checked the hazard and defrost illumination bulbs directly. They had no continuity when the defrost on bulb did. I imagine these are burnt out. Maybe a spike in the wiring when I first plugged the radio in. Or maybe the radio is faulty and is sending power through the illumination lead, and it fried the most sensitive lights. It ~is~ wired to the right lead because the radio dims with the headlights.

These bulbs have power. I don't feel the need at the time to check every single dim or dark bulb since they likely have the same condition. The defrost plug is a convenient place to check the illumination harness voltage.

But I mean, I just wired the harness, plugged it into the car, and everything was fine. No funny business. There's timing, and then there's leads from the circuit diagram and my multimeter to follow. Just because the problem happened at the same time as the install does not mean the radio is the only component I should investigate. At this time I do not have reason to suspect the radio, as far as my investigation goes.