Mother Of All Whore Threads Non-VIP Edition v.1

AlmosN8kd said:
Anyone here a novice electrical engineer of sorts? I'm pretty good, but am looking for a 2nd opinion on something (non-Civic related). Happy to take the conversation outside the thread (or, just post here); but, this is where I tend to hang out the most in this forum, so I'm asking here if anyone is willing to dive down a schematic rabbit hole with me.
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My college roommate was a EE and i took a circuits class like 20 years ago
 
AlmosN8kd said:
Ok, so if you remember me posting about my front bumper replacement on my Stealth (I've only mentioned it about 100 times, so, maybe not). Anyhow, one of the side effects of this I didn't account for ahead of time were the turn signal bulbs. With the original setup, the turn signal housings were amber; however, on the 99 3000GT setup, the turn signal housings are clear; not a big deal overall. However, I used what I had which were clear (white) light bulbs. Fortunately, with the reflector inside the 99 3000GT turn signal housing, the new turn signals appeared mostly amber; so, it is passable, at least temporarily. Anyhow, wanting to make it correct, and maybe improve things a bit, I've opted to install LED bulbs. Here is the difference (pictures don't carry the color quite as well as I'd hoped):
White bulbs:
View attachment 67750

Amber LEDs:
View attachment 67749

When I purchased the LEDs, I figured I'd replace front and rear at the same time and never have to worry about these ever again; I also knew that this would change the flash rate due to the reduced load on the circuit. Fortunately, the company I purchased the LEDs through offered a Flasher relay to adjust things without having to add resistors (I really didn't want to add resistors so I thought this would make things super simple). So, you might be asking yourself at this point, why am I now posing an electrical question?

Well, this is where things get semi-interesting (from a nerdy perspective). So, my car is a Stealth, which for all intents and purposes, is identical to a 3000GT; however, there remain some subtle differences between them, most of which are cosmetic. And, well, it turns out, the same is true for the turn signal/flasher circuit which caught me a bit by surprise; the Stealth (of my year's production) does not have a Flasher relay, it has a flasher module. I've been an enthusiast on this platform for more than 20yrs and didn't realize these were different (and, I know most every bolt on the car from looking at it). The background is, that after 1991, Mitsubishi abandoned the original Flasher module in place of a flasher relay; however, while Mitsubishi produced both the 3000GT and the Stealth in Nagoya, Japan, they did not make this same change on the Stealths. Why? I have no idea. I suspect, and this is purely a guess, that Chrysler didn't want to pay for the R&D to make the change (even though, Mitsubishi already did it and probably would've split costs - who knows?).

Anyhow, I now have a flasher relay I cannot use and a circuit that doesn't have enough load, so I've been diving down the rabbit hole of how to solve this problem. I've come up with the following options:
1) Modify the existing flasher module to support the reduced load and restore blink rate
2) Rewire the car to use a flasher module and install the updated one for the reduced load
3) Install resistors (or, install regular bulbs, at least in the front, temporarily to accomplish the same effect)
4) Replace the body harness with one from a 3000GT
5) Say "Fvck it" and deal with hyper blinking

All together, I think options 1-3 are the most viable and are ordered in desired preference. Option 4 has the potential to get exorbitantly expensive and is probably not worth the effort (not to mention, I do not know what other issues I'd run into as a result of this). Option 5 is just one I do not like.

Option 1: So, I've been trying to find someone who may be able to modify the module to work, I think this is a bit outside my knowledge and I'm not sure how much resistance can, or needs to, be added.

Option 3: I'd still prefer not to do. Mostly as I don't want to worry about the heat management associated with the resistors around plastic and other components (such as the light housings) or being exposed to the elements. I did this method on my motorcycle and haven't had any issues; but, the LED manufacturer had a specific warning about these so it gives me caution. As for reinstalling regular bulbs, it doesn't get past the long-term issue of finding bulbs getting increasingly more difficult as LEDs become more prominent. Fortunately, I have some used ones, and could put these in as when I tested the circuit (after replacing the fronts only) the blink rate was normal. But, the LEDs are considerably brighter than the incandescent bulbs which is pretty important (I think).

Option 2: This is where I've been spending most of my time, digging into the rabbit hole of the schematics for the car and where I'm looking for help.

Here is the wiring setup for the turn signal circuit on my car (the module is located in the lower left):
View attachment 67747

Here is the same circuit, except it is from one of the cars with a turn signal relay (the relay is located in the exact same area on the lower left):
View attachment 67748
Now, this is very odd as this is what I think is the base model version of the Stealth for 1994 - so, maybe Chrysler kept the module on the upper trim versions as it was a 'premium' even though going to the relay would've been possibly more sensible in 30yrs? Again, who knows why Chrysler didn't follow Mitsubishi in this change.

So, looking over the drawings at connecter E-30 in particular (this is the plug for the module), I think if I rewire the circuit as follows, I can use a flasher relay instead of a modified module (although, I think the modified module is likely the more elegant solution):

E-30 Pin 14 goes to Relay pin 2.
Relay Pin 3 goes to E-30 pin 12
Relay Pin 1 goes to E-30 pins 10 & 11
E-30 pin 2 goes to E-30 pins 1 & 7
E-30 pin 4 goes to E-30 pins 5 & 6
E-30 pin 3 is unused?

Does this look right to you? What did I miss? What questions do you have where I can add clarity and understanding? Why am I going to a Civic forum for help on a 30yr old Mitsubishi product (because this same question on the 3/S forums has gone unanswered)?


You may not have needed all this background, I probably could've said, how do I replace the module in picture A with a relay like in picture B but thought it would make a lot more sense to understand the context. I apologize if this was not the case and you have now wasted 30mins of your life reading all of my non-Civic nonsense.
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i think it makes sense, you would have to intercept some of those wires closer to their source i think, which could get messy but looking at the two diagrams you should be able to
 
AlmosN8kd said:
When I purchased the LEDs
Click to expand...
Can you post the specs of the LED's?

===================================
Resistor Formula:
R = (Vs - Vf) / If.

Vs: Supply Voltage (in Volts).
Vf: LED Forward Voltage (in Volts).
If: LED Forward Current (in Amperes). Make sure to convert milliamps (mA) to amperes (A) by dividing by 1000 (e.g., 20mA = 0.02A).


Example:
  • If you have a 5V power supply (Vs = 5V), an LED with a forward voltage of 2V (Vf = 2V), and a forward current of 20mA (If = 0.02A), the calculation would be:
    • R = (5V - 2V) / 0.02A = 3V / 0.02A = 150 Ohms.
  • Therefore, you would need a 150-ohm resistor.
 
webby said:
Can you post the specs of the LED's?

===================================
Resistor Formula:
R = (Vs - Vf) / If.

Vs: Supply Voltage (in Volts).
Vf: LED Forward Voltage (in Volts).
If: LED Forward Current (in Amperes). Make sure to convert milliamps (mA) to amperes (A) by dividing by 1000 (e.g., 20mA = 0.02A).


Example:
  • If you have a 5V power supply (Vs = 5V), an LED with a forward voltage of 2V (Vf = 2V), and a forward current of 20mA (If = 0.02A), the calculation would be:
    • R = (5V - 2V) / 0.02A = 3V / 0.02A = 150 Ohms.
  • Therefore, you would need a 150-ohm resistor.
Click to expand...

I figured it was basic Ohms Law but I don't know the current through the system with standard bulbs so I never got around to calculating the change in current for LEDs to compensate by adding in resistors in series. It's easier on the harness to do this; however, to do it inside the module is a bit different (I think, not certain on that).

But, the car has 1 dual filament 1157 bulb per corner (so, 4 bulbs total, 2 per signal side); these are the specs I got from the manufacturer (I don't know how accurate this is, these specs are not provided in the actual item I ordered which was tailored to the year/make/model of the car but by searching the bulb type - not sure why these would be different):

Each LED bulb:
Power (watts): 5.4
Operating Voltage: 9-16V
Current (amps @ 13.2V): 0.63
 
webby said:
Can you post the specs of the LED's?

===================================
Resistor Formula:
R = (Vs - Vf) / If.

Vs: Supply Voltage (in Volts).
Vf: LED Forward Voltage (in Volts).
If: LED Forward Current (in Amperes). Make sure to convert milliamps (mA) to amperes (A) by dividing by 1000 (e.g., 20mA = 0.02A).


Example:
  • If you have a 5V power supply (Vs = 5V), an LED with a forward voltage of 2V (Vf = 2V), and a forward current of 20mA (If = 0.02A), the calculation would be:
    • R = (5V - 2V) / 0.02A = 3V / 0.02A = 150 Ohms.
  • Therefore, you would need a 150-ohm resistor.
Click to expand...

Pkl9lnY.gif
 
r = (12v-9v)/.409a
3v/.409a = 7.33 ohm resistor

r=(12v-9v)/.63a
3v/.63a = 4.76 ohm resistor (if you'd go by their .63 rating).
 
webby said:
amps = watts/13.2
a= 5.4/13.2
a = .409 or 409 mA

I'm not sure why they are showing .63a in their description?
Click to expand...
webby said:
r = (12v-9v)/.409a
3v/.409a = 7.33 ohm resistor

r=(12v-9v)/.63a
3v/.63a = 4.76 ohm resistor (if you'd go by their .63 rating).
Click to expand...

I'm not sure where you're going with the 3V change in your resistance calculation; can you elaborate?


I approached this two different ways by doing variable elimination. Here's what I did:

What if we remove V from the equation and use the rated current?
V=IR & W=IV => W=(I^2)*R => R=W/(I^2) => R = 5.4 / (0.62^2) => R=13.61ohms . . . ? So, the total circuit would need that; I just have to find out how much is in there to know what to add.

Then, I decided I'd check my work, sort of, and figured the same could be done by removing current from the equation too?
I=V/R => W=(V^2)/R => R= (V^2)/W => R=(13.2^2)/5.4 => R=32.27ohms . . . ?
If I dropped the voltage to the minimum rating, this comes out to R=(9^2)/5.4 => R=15ohms
If I maxed the voltage, to the maximum rating, this comes out to R=(16^2)/5.4 => R=47.04ohms

So, in the end, I kinda concluded that the ratings are pretty much trash and I have no idea what would need to be added to the circuit to reduce flash rate.
 
webby said:
I was using 12v from the battery power, and then 9v from the led operating voltage. (12v-9v)/ the led amps.
Click to expand...
So, you're saying that to get the blink rate to slow, the LEDs need about 3Vs less than the system voltage (typically between 12-13.5V)? I read that as they LEDs will function with a minimum of 9V but no more than 16Vs supplied; so, I still think that there is something I'm missing.
 
AlmosN8kd said:
So, you're saying that to get the blink rate to slow, the LEDs need about 3Vs less than the system voltage (typically between 12-13.5V)? I read that as they LEDs will function with a minimum of 9V but no more than 16Vs supplied; so, I still think that there is something I'm missing.
Click to expand...
I looked up the 9th gen civic resistors, and I’m seeing 7ohm from one company and 11ohm resistors from another company being sold to stop the hyper blinking. Customers from both said it stopped their issue.

Doing the math on your setup a 5-7ohm resistor should work.

engineers, masters, phd.. please step in and tell me I’m a moron. It’s been about a century since I did any schematic stuff in school.
 
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webby said:
I looked up the 9th gen civic resistors, and I’m seeing 7ohm from one company and 11ohm resistors from another company being sold to stop the hyper blinking. Customers from both said it stopped their issue.

Doing the math on your setup a 5-7ohm resistor should work.

engineers, masters, phd.. please step in and tell me I’m a moron. It’s been about a century since I did any schematic stuff in school.
Click to expand...
I just bought some incandescent bulbs for the front (they're a tad easier to replace than the rears and I like how bright the rears are now with the LEDs) to toss in temporarily while I try and resolve this without in-line resistors (still considering either modifying the flasher module or converting to a standard flasher relay). But, while I was at the parts store, I did see an LED resistor kit, 2-6ohm resistors in the pack; so, I think your math checks out. EDIT: also, just went and checked the LED bulb manufacturer's page, their resistor kit (in line resistors) are 50W 6ohm each.

Rears (this is just the running light):
Before:Stealth Tail Light (Incandescent).png After: Stealth Tail Light (LED).png
 
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webby said:
I looked up the 9th gen civic resistors, and I’m seeing 7ohm from one company and 11ohm resistors from another company being sold to stop the hyper blinking. Customers from both said it stopped their issue.

Doing the math on your setup a 5-7ohm resistor should work.

engineers, masters, phd.. please step in and tell me I’m a moron. It’s been about a century since I did any schematic stuff in school.
Click to expand...

I have a Studio Arts Degree, and by my calculations, you're probably 100% right.

Trust me.
 
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