Post#4 above mentions the LED bulb in the ashtray also and having the same issue. If you put the incandescent bulb back and plug it in, does your issue still persist?
Help Needed - Electrical Issue
- Thread starter I_M_Legend
- Start date
The incandescent bulb removes the problem.
I just don't like this "solution".
I just don't like this "solution".
I think Heineken's solution of faking an incandescent bulb with a parallel resistor is the fix if you don't want an incandescent bulb; however, you might need to use a lower resistance. 1500 ohms would be equivalent to about a 0.1 watt bulb. That might not do the trick.
I feel a resistor in this case is just an incandescent with more steps and complexity.
It would be nice to solve this one narrowed down to a specific component. Though I might have to throw in the towel as I dug out my incandescent lamp for the ashtry; which feels like failure.
Did some more testing and results on "dim issue"
disconnect ash tray lamp (probably OEM radio too, not sure)
Key at ACC
-park light on
-brake on, dim issue begins
-park light off, dim issue persists
-brake off, dim issue ends
-brake on/off, no issue.
Key at Run
-park light on/off cycle
-brake on/off, dim issue in sync with brake status
-connect ashtray lamp
-brake on/off, NO ISSUE....until next park light on/off cycle
When connecting the ashtray lamp the dim issue goes off like a switch but there seems to be no audible sound at all...so unlikely anything mechanical.
I'm not sure what to look for: charged cap? latched mosfet?
(Noticed post no. 4. Probems of having kids that take over your workstation...because cool GPU...and I have to use the small screen like a caveman).
It would be nice to solve this one narrowed down to a specific component. Though I might have to throw in the towel as I dug out my incandescent lamp for the ashtry; which feels like failure.
Did some more testing and results on "dim issue"
disconnect ash tray lamp (probably OEM radio too, not sure)
Key at ACC
-park light on
-brake on, dim issue begins
-park light off, dim issue persists
-brake off, dim issue ends
-brake on/off, no issue.
Key at Run
-park light on/off cycle
-brake on/off, dim issue in sync with brake status
-connect ashtray lamp
-brake on/off, NO ISSUE....until next park light on/off cycle
When connecting the ashtray lamp the dim issue goes off like a switch but there seems to be no audible sound at all...so unlikely anything mechanical.
I'm not sure what to look for: charged cap? latched mosfet?
(Noticed post no. 4. Probems of having kids that take over your workstation...because cool GPU...and I have to use the small screen like a caveman).
I have an electrical issue too. Is there anyone who can help me with the Cabin fuse box?
I would like to have a pciture at least of the resistors because mine is so burned I can't identify what type of resistor was there.
Also a detailed schematics would help because my horn and tempomat doesn't work.
Thank you
I would like to have a pciture at least of the resistors because mine is so burned I can't identify what type of resistor was there.
Also a detailed schematics would help because my horn and tempomat doesn't work.
Thank you
This is the Integrated Control Unit 38600-SL0-01, 38600-SL0-A02 for anybody trying to help (I don't have my car apart, which is a rare occurrence).
I think WHRDNSX has one for sale, you might see if he can pop it open for a look see.
http://www.nsxprime.com/forum/showt...it-on-a-1991?p=1702951&viewfull=1#post1702951
I think WHRDNSX has one for sale, you might see if he can pop it open for a look see.
http://www.nsxprime.com/forum/showt...it-on-a-1991?p=1702951&viewfull=1#post1702951
I had a similar "false dimming signal" issue! That silly little bulb in the ashtray is critical. One can even leave the ring light around the cigarette lighter as an LED and just swap the ashtray light, and the issue will be resolved!
I swapped all interior control & courtesy bulbs to LED 6 months ago, which precipitated this issue. I have an S2000 cluster swap, and so I see the false dimming in both aftermarket stereo screen AND the s2k cluster (which gets its backlight dimming signal from the CLOCK RED/BLK lead, and which makes the issue much more annoying to live with!)
I have the modded flasher relay. I also have LEDs everywhere exterior, including marker lights. Never had issues with exterior LEDs, running them for years, no Brake Lamp Failure light.
Basically, you can run every LED you want on the interior... just don't mess with the ashtray bulb! I do like the work-arounds suggested for the ashtray light, maybe I'll try one of those in the future.
Bless all of you on this thread. I spent over 100 hours chasing this down, and spent way too much on new parts. All it took was Prime to save my soul.
I swapped all interior control & courtesy bulbs to LED 6 months ago, which precipitated this issue. I have an S2000 cluster swap, and so I see the false dimming in both aftermarket stereo screen AND the s2k cluster (which gets its backlight dimming signal from the CLOCK RED/BLK lead, and which makes the issue much more annoying to live with!)
I have the modded flasher relay. I also have LEDs everywhere exterior, including marker lights. Never had issues with exterior LEDs, running them for years, no Brake Lamp Failure light.
Basically, you can run every LED you want on the interior... just don't mess with the ashtray bulb! I do like the work-arounds suggested for the ashtray light, maybe I'll try one of those in the future.
Bless all of you on this thread. I spent over 100 hours chasing this down, and spent way too much on new parts. All it took was Prime to save my soul.
>I spent over 100 hours chasing this down
What did you do? I'm trying to figure out where the core cause is located.
What did you disconnect and still have the dim display on brake light?
What did you do? I'm trying to figure out where the core cause is located.
What did you disconnect and still have the dim display on brake light?
I actually did not have dim on brake light condition. Mine presented differently. (BUT, I did notice that just holding down the brake pedal would cause the voltage to creep upward continuously for as long as I held it (beyond normal driving, like 5 minutes). (I don't know how high it would creep if held indefinitely.)
(With LED in ashtray bulb) - RED/BLK voltages:
Key at position I: ~0.3V
Turn key to position II: ~2V (Interior doesn't dim, not quite enough voltage)
(Key at II) Turn on parking lights: ~12+V
(Key at II) Turn off parking lights: ~3V (interior STAYS DIM, additional 0.8-1V remains in the circuit)
Turn Key to III, release back to II: ~2V (cutting power to most things to start the car would "reset" voltage)
Turning Key from II back to I: ~0.3V
With stock bulb in ashtray, voltages in RED/BLK when headlight switch is off was well under 1V at all key positions.
Stuff I messed with (with ashtray bulb as LED):
Removing Fuse 5 would keep RED/BLK at 2V on headlight switch cycle, displays were normal behavior at all times.
Removing Fuse 4 or unplugging the 30P connector on the Climate Control Unit would reduce RED/BLK voltage to less than 1V at all key positions. Swapping CCUs did not change anything, (even with a brand new one). Displays normal at all times. Unplugging 14P CCU connector doesn't do anything.
Key at II - Unplugging the Dash Lights Brightness Control Unit (behind TCS ECU) would raise the voltage to 3.1V instantly, regardless of headlight switch (could stay off, never cycled). Reconnecting it would reduce voltage to 2V, displays reset to bright. Swapping DLBCU to new unit didnt change anything. Using jumper wires, only RED/BLK connection would change voltage (3V -> 2V), other 4 wires don't affect anything.
Key at II, RED/BLK at 3V from headlight cycle - Unplugging RH cluster connector, then reconnecting it, would drop voltage to 2V, displays reset to bright.
Removing Integrated Control Unit (38600-SL0-A01/A02) did not affect voltages much. Did not affect display behavior, issue remained. I bought a new one, but got the wrong part (-G01), and putting that in gave me a brake lamp warning on the dash. Not sure why, but that was curious.
Unplugging the headlight switch itself (LH steering stalk controls) after cycling didn't change anything. Swapping to a used unit didnt change anything.
Unplugging RH steering stalk controls didnt change anything.
Unplugging the turn signal cancel unit after cycling headlight switch didnt change anything. Changing to new unit didnt change anything. Headlight switch grounds through this (purple wire), so it must be connected to activate parking/headlights.
Unplugging popup headlight/brightness control (near LH cluster) didnt change anything.
Unplugging LH door switches didnt change anything.
Removing Fuse 34 didnt change anything.
Unplugging my LED tail/brake assemblies didnt change anything. Nor did side markers, nor did parking lights. RED/WHITE on fuse 39 was exactly the same as RED/BLK on fuse 38.
Not sure any of that helps, but just things I discovered on the long journey.
(With LED in ashtray bulb) - RED/BLK voltages:
Key at position I: ~0.3V
Turn key to position II: ~2V (Interior doesn't dim, not quite enough voltage)
(Key at II) Turn on parking lights: ~12+V
(Key at II) Turn off parking lights: ~3V (interior STAYS DIM, additional 0.8-1V remains in the circuit)
Turn Key to III, release back to II: ~2V (cutting power to most things to start the car would "reset" voltage)
Turning Key from II back to I: ~0.3V
With stock bulb in ashtray, voltages in RED/BLK when headlight switch is off was well under 1V at all key positions.
Stuff I messed with (with ashtray bulb as LED):
Removing Fuse 5 would keep RED/BLK at 2V on headlight switch cycle, displays were normal behavior at all times.
Removing Fuse 4 or unplugging the 30P connector on the Climate Control Unit would reduce RED/BLK voltage to less than 1V at all key positions. Swapping CCUs did not change anything, (even with a brand new one). Displays normal at all times. Unplugging 14P CCU connector doesn't do anything.
Key at II - Unplugging the Dash Lights Brightness Control Unit (behind TCS ECU) would raise the voltage to 3.1V instantly, regardless of headlight switch (could stay off, never cycled). Reconnecting it would reduce voltage to 2V, displays reset to bright. Swapping DLBCU to new unit didnt change anything. Using jumper wires, only RED/BLK connection would change voltage (3V -> 2V), other 4 wires don't affect anything.
Key at II, RED/BLK at 3V from headlight cycle - Unplugging RH cluster connector, then reconnecting it, would drop voltage to 2V, displays reset to bright.
Removing Integrated Control Unit (38600-SL0-A01/A02) did not affect voltages much. Did not affect display behavior, issue remained. I bought a new one, but got the wrong part (-G01), and putting that in gave me a brake lamp warning on the dash. Not sure why, but that was curious.
Unplugging the headlight switch itself (LH steering stalk controls) after cycling didn't change anything. Swapping to a used unit didnt change anything.
Unplugging RH steering stalk controls didnt change anything.
Unplugging the turn signal cancel unit after cycling headlight switch didnt change anything. Changing to new unit didnt change anything. Headlight switch grounds through this (purple wire), so it must be connected to activate parking/headlights.
Unplugging popup headlight/brightness control (near LH cluster) didnt change anything.
Unplugging LH door switches didnt change anything.
Removing Fuse 34 didnt change anything.
Unplugging my LED tail/brake assemblies didnt change anything. Nor did side markers, nor did parking lights. RED/WHITE on fuse 39 was exactly the same as RED/BLK on fuse 38.
Not sure any of that helps, but just things I discovered on the long journey.
awesome. Nice work. I pored over the ETM and found little to suspect.
What was left to test in your opinion?
I was going to just start unplugging a main harness upstream that the ashtray light is attached and see where it all ends.
From memory, there was a connector under the dash where the dash lights are distributed...which requires the dash to be removed...so incandescent lamp back into ashtray socket.
What was left to test in your opinion?
I was going to just start unplugging a main harness upstream that the ashtray light is attached and see where it all ends.
From memory, there was a connector under the dash where the dash lights are distributed...which requires the dash to be removed...so incandescent lamp back into ashtray socket.
Yes, there are 3 junction connectors under the dash that connect all of the lighting wires together - C451, C417 & C447. I didn't want to remove the dash either! Usually junction connectors are the last thing to check, and more common for multi-wire issues (multiple systems don't work).
In my initial diagnosing of this issue a few years back I traced the weird behavior to the climate control faceplate. With that disconnected the strangeness went away completely. I never figured out what exactly in the faceplate was responsible though.
One of my first attempted "fixes" was a resistor of appropriate wattage and resistance added to the circuit to mimic the current draw of the incandescent bulbs in the ash tray but in the end I decided to just keep the incandescent bulbs.
One of my first attempted "fixes" was a resistor of appropriate wattage and resistance added to the circuit to mimic the current draw of the incandescent bulbs in the ash tray but in the end I decided to just keep the incandescent bulbs.
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Did you maintain the incandescent lamps inside the CCU?
I tried incandescent back in the CCU, and it didn't solve my issue. Neither did putting in a brand new CCU ($$$$). But, CCU definitely plays a big role with key at II, it seems like the biggest power draw at that state coordinating fans, heater, compressor etc. Hilariously, the CCU dims normally (at least in my case) despite all of the other systems being abnormal (I think because its illumination control has its own return path through red wire in the 14P connector to C417 -> C447 back to the brightness control unit, like the rest of the adjustable-brightness control lights, and not like the single-wire dim signal of Clock/Stereo).
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