LED turn signal damage.

NZ.Z · 02-21-2017, 01:18 AM

Hi all,

I recently changed the turn signal bulbs to LED and used resistors to prevent the hyper flash.
Yesterday I was told by an auto electrician that Nissan use a Body Control Module to control all of the electrics and that the resistors could quite easily fry the module which would then cost $1500 - $1600 to replace.
He said that this could happen at anytime, a week, 4 months a year or years after fitment.
I've never heard of it happening before but was wondering how true it is and why it does it?

Could anyone shed any light on this?

SouthArk370Z · 02-21-2017, 06:08 AM

As long as the resistor is the proper value, you shouldn't have a problem.

LED lamps have a higher resistance than incandescent lamps and so do not pull as much current. The BCM senses the current when the light is turned on and goes to fast-blink mode if the current is below some threshold value. The resistor in parallel with the LED reduces the resistance of the circuit causing the current to rise above the threshold.

NZ.Z · 02-21-2017, 06:58 AM

Thanks for that SouthArk.
My only concern would be that the resistors are a higher wattage than the incandescent bulbs (50w), is this possibly too high for the BCM to comprehend for the turn signals and hense the fry up ?

SouthArk370Z · 02-21-2017, 07:15 AM

The wattage rating of resistors indicates how much power the resistors can dissipate (as heat) and does not effect their electrical performance. Nothing wrong with using a resistor with a higher wattage rating (as long as it will physically fit). As long as the ohms are right and wattage is equal to or greater than needed, you'll be OK.

NZ.Z · 02-21-2017, 07:49 AM

Hey, thanks once more SouthArk.
You are a legend on this forum, always one of the first to help out others, and I for one really appreciate your help.
Keep it up my friend.

Ghostvette · 02-21-2017, 08:17 AM

Quote:

Originally Posted by NZ.Z

Hi all,

I recently changed the turn signal bulbs to LED and used resistors to prevent the hyper flash.
Yesterday I was told by an auto electrician that Nissan use a Body Control Module to control all of the electrics and that the resistors could quite easily fry the module which would then cost $1500 - $1600 to replace.
He said that this could happen at anytime, a week, 4 months a year or years after fitment.
I've never heard of it happening before but was wondering how true it is and why it does it?

Could anyone shed any light on this?

The load resistors that are sold to prevent 'hyper-flash' are of the proper value and won't harm the BCM. Sounds more like a case of 'auto electrician' has absolutely no background in electronics.

NZ.Z · 02-21-2017, 01:44 PM

Hi Ghostvette,

Thanks for your input.
I thought the same thing at first, but then when he specifically mentioned that the wires leading to the turn signal bulb on the 370z are thinner than usual vehicles, is when it got me thinking that an auto electrician might know what he's talking about.

Ghostvette · 02-22-2017, 11:21 AM

Quote:

Originally Posted by NZ.Z

Hi Ghostvette,

Thanks for your input.
I thought the same thing at first, but then when he specifically mentioned that the wires leading to the turn signal bulb on the 370z are thinner than usual vehicles, is when it got me thinking that an auto electrician might know what he's talking about.

That's a clear indication that he's clueless. There's no difference in wire size on a Z as compared to any other vehicle.

Any way, make sure you have a good connection on the load resistor and it's installed with some kind of a heat sink on it. They do tend to get warm enough to melt insulation if they are laying on the wiring harness. I put mine on a piece of 1/8" aluminum with heat sink compound between the resistor and the block, then covered the whole thing with heat shrink. No problems so far. Oh, and you only need one on each side.

SouthArk370Z · 02-22-2017, 11:44 AM

As per Ghostvette, your "auto electrician" doesn't understand how electricity works. LEDs, since they have a higher resistance than OEM incandescents, allow less current to flow (which triggers fast-blink mode). The resistor in parallel with the LED lowers the circuit resistance, raising the current to something closer to what it is supposed to be.

And the resistor will get HOT. Some people add a heat sink; some people bolt the resistor to the frame or a metal body part for a heat sink. Keep away from any plastic parts.

kenchan · 02-22-2017, 12:37 PM

Dogdamn.. too technical for me. I just use stock bulbs and never had a problem.

Never understood super bright plate lighting too.

02-21-2017, 01:18 AM	#1 (permalink)
NZ.Z Base Member Join Date: Jan 2016 Location: Tauranga, New Zealand Posts: 39 Drives: 09 370z, platinum t. Rep Power: 9	LED turn signal damage. Hi all, I recently changed the turn signal bulbs to LED and used resistors to prevent the hyper flash. Yesterday I was told by an auto electrician that Nissan use a Body Control Module to control all of the electrics and that the resistors could quite easily fry the module which would then cost $1500 - $1600 to replace. He said that this could happen at anytime, a week, 4 months a year or years after fitment. I've never heard of it happening before but was wondering how true it is and why it does it? Could anyone shed any light on this?

02-21-2017, 06:08 AM	#2 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324197	As long as the resistor is the proper value, you shouldn't have a problem. LED lamps have a higher resistance than incandescent lamps and so do not pull as much current. The BCM senses the current when the light is turned on and goes to fast-blink mode if the current is below some threshold value. The resistor in parallel with the LED reduces the resistance of the circuit causing the current to rise above the threshold. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

02-21-2017, 07:15 AM	#4 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324197	The wattage rating of resistors indicates how much power the resistors can dissipate (as heat) and does not effect their electrical performance. Nothing wrong with using a resistor with a higher wattage rating (as long as it will physically fit). As long as the ohms are right and wattage is equal to or greater than needed, you'll be OK. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

02-21-2017, 07:49 AM	#5 (permalink)
NZ.Z Base Member Join Date: Jan 2016 Location: Tauranga, New Zealand Posts: 39 Drives: 09 370z, platinum t. Rep Power: 9	Hey, thanks once more SouthArk. You are a legend on this forum, always one of the first to help out others, and I for one really appreciate your help. Keep it up my friend. JARblue and falicfr like this.

02-22-2017, 11:44 AM	#9 (permalink)
SouthArk370Z Premium Member Join Date: Nov 2010 Location: South Arkansas Posts: 8,435 Drives: 2014 Challenger Rep Power: 324197	As per Ghostvette, your "auto electrician" doesn't understand how electricity works. LEDs, since they have a higher resistance than OEM incandescents, allow *less* current to flow (which triggers fast-blink mode). The resistor in parallel with the LED lowers the circuit resistance, raising the current to something closer to what it is supposed to be. And the resistor will get HOT. Some people add a heat sink; some people bolt the resistor to the frame or a metal body part for a heat sink. Keep away from any plastic parts. NZ.Z likes this. __________________ Steering Lock Links - Search The370Z Bookmarklet - FSM @ NICOclub Mankind has progressed past the need for war but we haven't evolved that far. - NachoMahma

02-21-2017, 06:58 AM	#3 (permalink)
NZ.Z Base Member Join Date: Jan 2016 Location: Tauranga, New Zealand Posts: 39 Drives: 09 370z, platinum t. Rep Power: 9	Thanks for that SouthArk. My only concern would be that the resistors are a higher wattage than the incandescent bulbs (50w), is this possibly too high for the BCM to comprehend for the turn signals and hense the fry up ?

02-21-2017, 01:44 PM	#7 (permalink)
NZ.Z Base Member Join Date: Jan 2016 Location: Tauranga, New Zealand Posts: 39 Drives: 09 370z, platinum t. Rep Power: 9	Hi Ghostvette, Thanks for your input. I thought the same thing at first, but then when he specifically mentioned that the wires leading to the turn signal bulb on the 370z are thinner than usual vehicles, is when it got me thinking that an auto electrician might know what he's talking about.

02-22-2017, 12:37 PM	#10 (permalink)
kenchan A True Z Fanatic Join Date: Aug 2009 Location: N/A Posts: 76,801 Drives: N/A Rep Power: 141520	Dogdamn.. too technical for me. I just use stock bulbs and never had a problem. Never understood super bright plate lighting too.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
LED turn signal damage.	NZ.Z	Nissan 370Z General Discussions	1	02-23-2017 07:18 PM
LED turn signal damage.	NZ.Z	Exterior & Interior	3	02-22-2017 09:16 AM
[WTB] Turn Signal Shroud	bbermann	Parts for sale (Private Classifieds)	5	08-07-2016 07:13 AM
Turn signal acting up.	Ill	Nissan 370Z Owners Manual / Service Manuals	2	06-14-2012 12:36 PM
Loose turn signal	Big J	Nissan 370Z Warranty / Scheduled Maintenance / Servicing / Repairs	1	01-26-2011 02:54 PM