speedometer light problem - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

jeb · 11-24-2008, 01:54 PM

i just put in a new cd player an had to wire it straight in because the original harness was cut an i have about 4 wires left over an dont know where they go. 2 are red with a yellow stripe am the other 2 are red with a blue stripe. would these have anything to do with my dash not lighting up?

ryguy · 11-24-2008, 01:57 PM

There is a ground in there that has to be grounded. Here, I made a picture.

The wire splits off from one red and yellow wire in the harness, so you only need to ground one of the two you have.

jeb · 11-24-2008, 02:03 PM

i have two of those wires. is one suppose to go to the cd player?

ryguy · 11-24-2008, 02:36 PM

No, just ground both of them to the chassis. Originally I believe they controlled the dimmer function on the factory radio.

jeb · 11-24-2008, 02:39 PM

ok ill try it. thanks

s14freak · 12-21-2008, 10:00 AM

I know its an old thread, but did it work? I had the same problem in my s14 when i did the stereo. I already bought reverse glow faces, but it would be nice to find a solution in case those take a shit too.

projectRDM · 12-21-2008, 10:17 AM

Um, this thread is full of wrong. The red/yellow wire in question is the dimmer lead to the OE radio, you do NOT ground it unless you no longer need a dimmer. The red/blue is the illumination wire, sounds like the OP either blew a fuse or the dimmer went bad, the correct fix is not to just ground the dimmer lead though, that's fucking stupid.

To the S14 guy, check fuses. Simple as that, when a radio is pulled and someone cuts all the wiring you usually ground something out on accident. If ALL fuses are good, the dimmer switch could be bad. The red/blue wire behind the radio should have +12V when the lights are on, the red/yellow should show a ground, but it's a variable ground through the dimmer. Grounding it negates the dimmer completely.

wow-thats-a-cool-car · 12-21-2008, 08:43 PM

Check the little white box under the dash next to the fuse pannel. That box likes to short out so borrow a friends and see if that does anything.
-Best of Luck

ryguy · 12-21-2008, 11:32 PM

Quote:

Originally Posted by projectRDM

Um, this thread is full of wrong. The red/yellow wire in question is the dimmer lead to the OE radio, you do NOT ground it unless you no longer need a dimmer. The red/blue is the illumination wire, sounds like the OP either blew a fuse or the dimmer went bad, the correct fix is not to just ground the dimmer lead though, that's fucking stupid.

To the S14 guy, check fuses. Simple as that, when a radio is pulled and someone cuts all the wiring you usually ground something out on accident. If ALL fuses are good, the dimmer switch could be bad. The red/blue wire behind the radio should have +12V when the lights are on, the red/yellow should show a ground, but it's a variable ground through the dimmer. Grounding it negates the dimmer completely.

The dimmer has to be grounded for the panel to light up. That's the only way it would light on my hatch. I know it works.

g6civcx · 12-22-2008, 12:23 AM

Quote:

Originally Posted by ryguy

The dimmer has to be grounded for the panel to light up. That's the only way it would light on my hatch. I know it works.

This is not correct. Russ's post above is correct. Let me clarify for you.

The S13 radio harness has 2 pairs of red/blue and red/yellow wires. One pair goes to the CD player and the other pair goes to the tape deck.

If you only have a single unit, like tape deck only, cd only, or aftermarket headunit, you can seal off one pair. You only need one pair left.

The parking light switch delivers power to the red/blue wire. Ground is supplied via the red/yellow wire. The red/yellow wire goes to the time control unit (TCU), which is controlled by the dimmer switch to deliver variable ground to the red/yellow wire.

Based on the TCU's direction, the red/yellow wire will pull a certain amount of current, thereby giving you dim or bright light as selected.

Your light can work, albeit only at full bright, by grounding the red/yellow wire, but keep in mind you're bypassing the dimmer switch and the TCU completely.

It's okay, but it's not the correct way according to the factory.

Also, keep in mind that some aftermarket headunits, especially older/cheaper ones, do not have dimming capability, i.e. the display is always on full bright whenever the headunit is on. For these units, you seal off both pairs of wires and don't worry about them.

projectRDM · 12-22-2008, 09:29 AM

Quote:

Originally Posted by ryguy

The dimmer has to be grounded for the panel to light up. That's the only way it would light on my hatch. I know it works.

See post above for a detailed description. Now read below for mine.

If the wire had to be grounded for it to work, why was it not grounded from the factory? True, you have fixed your dash light problem by grounding it, but you've bypassed a complete circuit in the car by doing so. That's not a 'fix', that's a band aid. You've done the same thing as just pouring more oil in to 'fix' a leak, you still have a problem somewhere you just did something to cover it up. There's still a damaged circuit somewhere in your car.

g6civcx · 12-22-2008, 10:22 AM

I removed the dimmer and TCU from my car (and 99% of the stock electronics as well) and I ground the red/yellow wire directly to chassis.

But you should fix your dimmer switch correctly because the problem may be with the TCU. Having a bad dimmer switch per se is not bad, but the TCU controls other things as well so if the TCU is fried you need to fix it.

93nismo · 12-30-2008, 09:58 PM

It's a common problem in 240's, no dash lights.
If you have had an after market stereo installed in your car and the factory nissan wire harness was cut off to wire the new unit there is a big chance that your TCU is burned out. The TCU is a timing control unit. It is a small white box that is located to the left of your fuses that are under the driver side dash.

You can either replace it by pulling one from a car at a junkyard or pay a lot of money for one at a dealers.
The other choice is opening the little box up and soldering a jumper wire over a trace which is burned out with a soldering iron that you can buy at radioshack for 5 bucks. Soldering it will only take a minute if you have the skills.
If you take it off and unscrew it, you will see a Printed Circuit Board with a lot of mounted components. The side with fewer mounted components that looks like it has green paths running around will most likely have one of those traces burned out. You can tell if its is black. I didn't replace my unit and just fixed it buy soldering in a wire where the burned out trace was. But if you find that yours is burned out you can just replace it, and that will fix the problem too.
The problem is the circuit that lights the dashboard lights, as well as the climate control knobs, and glove compartment is powered by a red wire with yellow stripe (-) and red wire with blue stripe (+). These wires also go to the wire harness for the stereo and are usually not used.
If they are touched together during the stereo installation the TCU gets fried. Usually the fuse in the dimmer switch should go first, but after opening the TCU, I have found that the PCB (printed circuit board) is made by hand. I have some experience in PCB design and notice a lot of design errors. The traces that run on the board are to thin in some areas, so the TCU is the first to go.
I have seen people fix the problem by grounding the red wire with yellow stripe. This will fix the problem, however the dimmer switch will not work after you have done that.

thats how easy it is, so says whoever this dude is. i checked the box in mine and ive got a burned out trace. im just gunna go to a junk yard and see if i cant find 1 and put in and hope to god it works. as for a temp fix, friend gave me a LED strip thingy and it lights it up fine :P looks retarded as shit tho

esqueue · 02-09-2009, 04:35 PM

I have the same problem. I have an aftermarket stereo and I've grounded out one of my red wires with the yellow stripe but still no function. What is the next step that I should try?

I notice that the only interior light that works is the cigarette ashtray light. I will look for the power wire in the FSM and run that to the cigarette ashtray light's wire. That should work.

I will post results.

*Vatche* · 02-09-2009, 07:11 PM

^^ did you try replacing the audio fuse first?

check all your fuses to be honest. i burn them out frequently.

the speedo is connected to the stereo fuse on my hud cluster.

esqueue · 02-11-2009, 01:43 AM

Quote:

Originally Posted by sr20detman

^^ did you try replacing the audio fuse first?

check all your fuses to be honest. i burn them out frequently.

the speedo is connected to the stereo fuse on my hud cluster.

Yeah, all fuses behind the driver side kick panel are good.

esqueue · 02-11-2009, 08:38 PM

Nevermind, it now works. It is very dim so I couldn't tell that it worked until tonight. The climate control and buttons around the cluster (i.e. hazard, flip-up) don't light up but the green light on the climate control switch work.

I guess I can live with that. Unless someone have another thing to try.

11-24-2008, 01:54 PM	#1
jeb Zilvia Member Join Date: Sep 2008 Location: here Posts: 239 Trader Rating: (4) Feedback Score: 4 reviews	speedometer light problem i just put in a new cd player an had to wire it straight in because the original harness was cut an i have about 4 wires left over an dont know where they go. 2 are red with a yellow stripe am the other 2 are red with a blue stripe. would these have anything to do with my dash not lighting up?

11-24-2008, 01:57 PM	#2
ryguy Zilvia FREAK! Join Date: Oct 2006 Location: Chicago Suburbs Age: 32 Posts: 1,544 Trader Rating: (5) Feedback Score: 5 reviews	There is a ground in there that has to be grounded. Here, I made a picture. The wire splits off from one red and yellow wire in the harness, so you only need to ground one of the two you have. __________________

11-24-2008, 02:36 PM	#4
ryguy Zilvia FREAK! Join Date: Oct 2006 Location: Chicago Suburbs Age: 32 Posts: 1,544 Trader Rating: (5) Feedback Score: 5 reviews	No, just ground both of them to the chassis. Originally I believe they controlled the dimmer function on the factory radio. __________________

12-21-2008, 10:17 AM	#7
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 47 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	Um, this thread is full of wrong. The red/yellow wire in question is the dimmer lead to the OE radio, you do NOT ground it unless you no longer need a dimmer. The red/blue is the illumination wire, sounds like the OP either blew a fuse or the dimmer went bad, the correct fix is not to just ground the dimmer lead though, that's fucking stupid. To the S14 guy, check fuses. Simple as that, when a radio is pulled and someone cuts all the wiring you usually ground something out on accident. If ALL fuses are good, the dimmer switch could be bad. The red/blue wire behind the radio should have +12V when the lights are on, the red/yellow should show a ground, but it's a variable ground through the dimmer. Grounding it negates the dimmer completely. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

12-21-2008, 08:43 PM	#8
wow-thats-a-cool-car Post Whore! Join Date: Mar 2008 Location: California Posts: 2,663 Trader Rating: (6) Feedback Score: 6 reviews	Check the little white box under the dash next to the fuse pannel. That box likes to short out so borrow a friends and see if that does anything. -Best of Luck __________________

11-24-2008, 02:03 PM	#3
jeb Zilvia Member Join Date: Sep 2008 Location: here Posts: 239 Trader Rating: (4) Feedback Score: 4 reviews	i have two of those wires. is one suppose to go to the cd player?

11-24-2008, 02:39 PM	#5
jeb Zilvia Member Join Date: Sep 2008 Location: here Posts: 239 Trader Rating: (4) Feedback Score: 4 reviews	ok ill try it. thanks

12-21-2008, 10:00 AM	#6
s14freak Leaky Injector Join Date: Sep 2008 Location: North Charleston. SC Age: 33 Posts: 119 Trader Rating: (6) Feedback Score: 6 reviews	I know its an old thread, but did it work? I had the same problem in my s14 when i did the stereo. I already bought reverse glow faces, but it would be nice to find a solution in case those take a shit too.

12-22-2008, 10:22 AM	#12
g6civcx Post Whore! Join Date: Apr 2004 Location: Virginia, USA Posts: 5,764 Trader Rating: (5) Feedback Score: 5 reviews	I removed the dimmer and TCU from my car (and 99% of the stock electronics as well) and I ground the red/yellow wire directly to chassis. But you should fix your dimmer switch correctly because the problem may be with the TCU. Having a bad dimmer switch per se is not bad, but the TCU controls other things as well so if the TCU is fried you need to fix it.

12-30-2008, 09:58 PM	#13
93nismo Zilvia Addict Join Date: Dec 2008 Location: sycamore il Posts: 765 Trader Rating: (14) Feedback Score: 14 reviews	It's a common problem in 240's, no dash lights. If you have had an after market stereo installed in your car and the factory nissan wire harness was cut off to wire the new unit there is a big chance that your TCU is burned out. The TCU is a timing control unit. It is a small white box that is located to the left of your fuses that are under the driver side dash. You can either replace it by pulling one from a car at a junkyard or pay a lot of money for one at a dealers. The other choice is opening the little box up and soldering a jumper wire over a trace which is burned out with a soldering iron that you can buy at radioshack for 5 bucks. Soldering it will only take a minute if you have the skills. If you take it off and unscrew it, you will see a Printed Circuit Board with a lot of mounted components. The side with fewer mounted components that looks like it has green paths running around will most likely have one of those traces burned out. You can tell if its is black. I didn't replace my unit and just fixed it buy soldering in a wire where the burned out trace was. But if you find that yours is burned out you can just replace it, and that will fix the problem too. The problem is the circuit that lights the dashboard lights, as well as the climate control knobs, and glove compartment is powered by a red wire with yellow stripe (-) and red wire with blue stripe (+). These wires also go to the wire harness for the stereo and are usually not used. If they are touched together during the stereo installation the TCU gets fried. Usually the fuse in the dimmer switch should go first, but after opening the TCU, I have found that the PCB (printed circuit board) is made by hand. I have some experience in PCB design and notice a lot of design errors. The traces that run on the board are to thin in some areas, so the TCU is the first to go. I have seen people fix the problem by grounding the red wire with yellow stripe. This will fix the problem, however the dimmer switch will not work after you have done that. thats how easy it is, so says whoever this dude is. i checked the box in mine and ive got a burned out trace. im just gunna go to a junk yard and see if i cant find 1 and put in and hope to god it works. as for a temp fix, friend gave me a LED strip thingy and it lights it up fine :P looks retarded as shit tho

02-09-2009, 04:35 PM	#14
esqueue Leaky Injector Join Date: Jan 2009 Location: Long Beach, CA Age: 40 Posts: 53 Trader Rating: (1) Feedback Score: 1 reviews	I have the same problem. I have an aftermarket stereo and I've grounded out one of my red wires with the yellow stripe but still no function. What is the next step that I should try? I notice that the only interior light that works is the cigarette ashtray light. I will look for the power wire in the FSM and run that to the cigarette ashtray light's wire. That should work. I will post results.

02-11-2009, 08:38 PM	#17
esqueue Leaky Injector Join Date: Jan 2009 Location: Long Beach, CA Age: 40 Posts: 53 Trader Rating: (1) Feedback Score: 1 reviews	Nevermind, it now works. It is very dim so I couldn't tell that it worked until tonight. The climate control and buttons around the cluster (i.e. hazard, flip-up) don't light up but the green light on the climate control switch work. I guess I can live with that. Unless someone have another thing to try.

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