Topic: Lights Pulse When Driving (Help)

[86moneypit]

Hi All,

I have a 86 runner with a 22re

I have recently noticed when I drive and have the lights on they pulse, the battery gage inside pulses to match the lights, everything runs fine and works just don’t know what this is from.

Any help on what to check is appreciated.

Thanks Martin

[Cheesemaker]

First of all, what kind of stereo system do you have?  If you have a big one, it will pull from the system causing the lights to dance.

What condition is your battery cables in, and your ground strap?  I replaced my factory ones with heavy gauge sealed end cables.  And I use those felt washers and anti corrosion spray on my battery terminals.  It keeps corrosion away.  And when I installed my motor 6 years ago, I put in new ground wires on the exhaust side, valve cover to firewall, and neg post to fender.  And made sure I roughed up the area to get a good contact.

Another thing, with the engine running, take a volt ohm meter and test the amount of voltage it flowing through the battery.  A normal good system should be 13.5 to 14.2 volts.  (around there)   After you have that baseline, now turn on headlights, heater, wipers, and stereo system, and see what the volts are.   If it really doesn't change then the issue might be a battery, but if it does, you might need to look at your alt.  But you need to have a good strong battery too.  So, make sure your battery is in really good condition before assuming your alt it the culprit. 

After that, turn everything off including motor.  See what your volts is reading.  The volts should hold steady without dropping. 

And how old is your battery?  If you don't know use this chart.  On all batteries there will be a round sticker with a letter / number.

A --  Jan
B --  Feb
C --  March
D --  April
E --  May
F --  June
G --  July
H --  Aug
I --  Sept
J --  Oct
K --  Nov
L --  Dec

And the number represents the last digit of the year it was made.  So if you see F/9.  It was made in June 2009.



After re-reading your post, another question is, do they pulse when you have your blinkers on?  My alt gauge flickers a little too, when I have my blinkers on, only because they share the same ground.  But my headlights don't flicker.  Just the gauge.

[86moneypit [OP]]

Dam man thanks for all the good info im going to check some stuff this week when i get some time.

I replaced this motor 2 years ago and did all the ground stuff you are talking about at that time.

Battery is a Blue top that i bought refurbished from Daves off road last year.

Stereo is pretty big  1 10" and 2 8" subs with 2 amps.

Also have rock lights and front spot lights. 

I have a one wire GM Alt. breaks and alternator ready to go in just no time to do the swap yet.

The lights Pulse when driving but haven’t checked with stereo off.

I’ll have to do some checking with a meter and see what’s what.

Thanks for all the info man.

[Cheesemaker]

I would get cracking on the GM alt swap. 

Another thing to look at if you do have a large system is a Capacitor.  I'm not talking Flux Capacitor.   
http://www.millionbuy.com/view_product_LNZLQ16CAP_LANZAR-LQ16CAP-1.6-Farad-12V-Power-Digital-CAPACITOR.html

It will help with the bass hits.  It's like a coil for your ignition system.  It takes low voltage, and amplifies it, and then discharges it when you amps needs the power to make the bass hit hard.  And it wires inline of the power wire to the amps.

[86moneypit [OP]]

Thanks for the link,  I have one on there now but got it used from a friend.  I might replace it for that price. 

[rubiconrunnerneville]

the chevy alt swap will help. what size capacitor do you have? and whats the wattage on the 2 amps draw example one 500watts the other 300watts total 800watts.the lights on my tacoma use to dime when my sub hit with a 500 watt cap till I switched to a 1000 watt cap now with 4" piaa's with my sub hitting no lights dime and I have a walmart battery in my tcoma

[Nimyad]

X3 on the 1 wire swap, I did one on my first gen and I never got lights to dim. Even when running a winch at idle. In my 3rd gen I can make my battery gauge move a little if I turn up my stereo (single 10 and 250w amp) but my lights don't flicker, that's with a factory alt.