S13, hitting the brakes illuminates the dash - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

denkigrve · 01-25-2010, 11:05 AM

So this morning I woke up to start my car, and I noticed that when I hit the brakes it illuminates the dash. I've also noticed that the fuel pump whines more when the brakes are hit. The pitch definitely increases when you hit the brakes.

808_fairladyz · 01-27-2010, 01:29 PM

I've little experience in automotive repair, so take my advise as is, but it sounds as if something maybe wrong with your altenator. Your battery does not generate power but stores and discharges it as need, so if your seeing an increase in current when using your brakes, it must be your altenator or other related components. Uselly when you depress the brake pedals, your brake light goes on. That in itself does draw current from the electrical system so an increase in the illumination of your lights is not supposed to happen and could mean that your altenator may be flowing more unresticted current then it's supposed to. Have your car charging system tested for altenator malfunction. I hope this info helps or others can chime in and add or correct me if i'm wrong.

denkigrve · 01-27-2010, 02:49 PM

Interesting. I hadn't even thought of that. I'll have it checked out. I might explain some of the idle surging that I'm getting as well since it's still happening even after we fixed the vacuum leaks and PCV. Thanks.

HI huh? My mother in law lives in Mililani Town on Oahu, and my fiance grew up there. I'm dying to get to the big Island on one of our next trips to see her.

808_fairladyz · 01-27-2010, 03:16 PM

Hope it works out for you. I've had my S13.4 for about a 1 yr now and talk about a learning format. As far troubleshooting problems, my learning curve is high because of this car. Everything from my front end conversion adjustments, leaking exhaust system, leaking frt and rr main oil seals, faulty #3 injector, shitty alt belt, and shitty battery(most have been repaired or replaced). I love it. shootz brah.

whowutwut · 01-27-2010, 04:01 PM

interesting assessment... I have a similar problem that doesn't happen often but when it does it's so retarded looking..

it happens when I have the turn signal on and on the brakes (red light, stop sign, etc) the dash lights and gauges all flash with the turn signal. (as if i'm turning on the lights and off and on and off). . . However. i decided not to investigate it because it's a pain to take out the gauge cluster and dash to get to the wiring of my gauges. my thoughts is maybe a bad ground...

do you have anything tapped into your wires back there?

denkigrve · 01-27-2010, 04:51 PM

Nothing is tapped that I'm aware of. Most of the electronics in the car are stock. The only change to the stock harness was the aftermarket head unit. My lighter also doesn't work, nor does the seatbelt sensor for the lap band. So there could be some grounding issues with part of the harness on my part.

However the faulty alternator makes sense. I don't think mines been touched in a long time.

808_fairladyz · 01-27-2010, 07:55 PM

I forgot to mension it, but i used to have a ground problem. Actully alot of them. On the side of each flip up light housing (you can actully see it near the battery), there is a large grounding source where a bunch of ground wires converge onto one spot held down by a single screw. Aparentlly, during the front end conversion process, both of these grounding packs got cut into, causing myself all kinds of problems including my dashlights. I'd think that if the screw was to become loose, dmged with heavy oxidation, or dmged during modding, that problems may accure. I did repair and relocate my grounds, then ran 8 ga. power cables from that spot, to my chassis normal ground source (on each side of my engine bay), to motor, then to battery. No problems since.

LayNLow · 01-28-2010, 12:15 AM

Quote:

Originally Posted by whowutwut

interesting assessment... I have a similar problem that doesn't happen often but when it does it's so retarded looking..

it happens when I have the turn signal on and on the brakes (red light, stop sign, etc) the dash lights and gauges all flash with the turn signal. (as if i'm turning on the lights and off and on and off). . . However. i decided not to investigate it because it's a pain to take out the gauge cluster and dash to get to the wiring of my gauges. my thoughts is maybe a bad ground...

do you have anything tapped into your wires back there?

I had the same problem when my signal bulb hit the ground and the filaments were touching. You are getting something that is backfeeding power into your cluster from your blinkers.
OP should check for something similar.

projectRDM · 01-28-2010, 08:17 AM

Yes, the bulbs are backfeeding current through the other circuit. Using the wrong bulb will do that.

01-25-2010, 11:05 AM	#1
denkigrve Join Date: Jan 2010 Location: Bay Area, CA Age: 39 Posts: 27 Trader Rating: (0) Feedback Score: 0 reviews	S13, hitting the brakes illuminates the dash So this morning I woke up to start my car, and I noticed that when I hit the brakes it illuminates the dash. I've also noticed that the fuel pump whines more when the brakes are hit. The pitch definitely increases when you hit the brakes. Last edited by denkigrve; 01-25-2010 at 11:56 AM..

01-28-2010, 08:17 AM	#9
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 47 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	Yes, the bulbs are backfeeding current through the other circuit. Using the wrong bulb will do that. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

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01-27-2010, 01:29 PM	#2
808_fairladyz Join Date: Jan 2010 Location: Hilo, Hi Age: 44 Posts: 3 Trader Rating: (0) Feedback Score: 0 reviews	I've little experience in automotive repair, so take my advise as is, but it sounds as if something maybe wrong with your altenator. Your battery does not generate power but stores and discharges it as need, so if your seeing an increase in current when using your brakes, it must be your altenator or other related components. Uselly when you depress the brake pedals, your brake light goes on. That in itself does draw current from the electrical system so an increase in the illumination of your lights is not supposed to happen and could mean that your altenator may be flowing more unresticted current then it's supposed to. Have your car charging system tested for altenator malfunction. I hope this info helps or others can chime in and add or correct me if i'm wrong.

01-27-2010, 02:49 PM	#3
denkigrve Join Date: Jan 2010 Location: Bay Area, CA Age: 39 Posts: 27 Trader Rating: (0) Feedback Score: 0 reviews	Interesting. I hadn't even thought of that. I'll have it checked out. I might explain some of the idle surging that I'm getting as well since it's still happening even after we fixed the vacuum leaks and PCV. Thanks. HI huh? My mother in law lives in Mililani Town on Oahu, and my fiance grew up there. I'm dying to get to the big Island on one of our next trips to see her.

01-27-2010, 03:16 PM	#4
808_fairladyz Join Date: Jan 2010 Location: Hilo, Hi Age: 44 Posts: 3 Trader Rating: (0) Feedback Score: 0 reviews	Hope it works out for you. I've had my S13.4 for about a 1 yr now and talk about a learning format. As far troubleshooting problems, my learning curve is high because of this car. Everything from my front end conversion adjustments, leaking exhaust system, leaking frt and rr main oil seals, faulty #3 injector, shitty alt belt, and shitty battery(most have been repaired or replaced). I love it. shootz brah.

01-27-2010, 04:01 PM	#5
whowutwut Leaky Injector Join Date: Oct 2003 Location: NY Posts: 85 Trader Rating: (0) Feedback Score: 0 reviews	interesting assessment... I have a similar problem that doesn't happen often but when it does it's so retarded looking.. it happens when I have the turn signal on and on the brakes (red light, stop sign, etc) the dash lights and gauges all flash with the turn signal. (as if i'm turning on the lights and off and on and off). . . However. i decided not to investigate it because it's a pain to take out the gauge cluster and dash to get to the wiring of my gauges. my thoughts is maybe a bad ground... do you have anything tapped into your wires back there?

01-27-2010, 04:51 PM	#6
denkigrve Join Date: Jan 2010 Location: Bay Area, CA Age: 39 Posts: 27 Trader Rating: (0) Feedback Score: 0 reviews	Nothing is tapped that I'm aware of. Most of the electronics in the car are stock. The only change to the stock harness was the aftermarket head unit. My lighter also doesn't work, nor does the seatbelt sensor for the lap band. So there could be some grounding issues with part of the harness on my part. However the faulty alternator makes sense. I don't think mines been touched in a long time.

01-27-2010, 07:55 PM	#7
808_fairladyz Join Date: Jan 2010 Location: Hilo, Hi Age: 44 Posts: 3 Trader Rating: (0) Feedback Score: 0 reviews	I forgot to mension it, but i used to have a ground problem. Actully alot of them. On the side of each flip up light housing (you can actully see it near the battery), there is a large grounding source where a bunch of ground wires converge onto one spot held down by a single screw. Aparentlly, during the front end conversion process, both of these grounding packs got cut into, causing myself all kinds of problems including my dashlights. I'd think that if the screw was to become loose, dmged with heavy oxidation, or dmged during modding, that problems may accure. I did repair and relocate my grounds, then ran 8 ga. power cables from that spot, to my chassis normal ground source (on each side of my engine bay), to motor, then to battery. No problems since.