fc3schick87

iTrader: (1)

ok so, i was at the track tuning my car back in october. and on the way home some one informed me my tail lights were not working. i pulled over and replaced the fuse, the worked for about 5 min and then they fuse popped again.

im thinking wheel hopping possibly shook something loose.

i have a multi-meter. and i am pretty darn good with wireing. but i have not ever had to actually diagnose something like this before.


i have a plan a, and a plan b.

plan a, find and fix the actual issue (not sure how to find it with multimeter)

plan b, re-wire tail lights with new ground, and new power source using appropriate inline fuse and relay.

HAILERS2

Are you sure your front and read SIDE lights did not also go south the same time the tail lights went?????? Common problem if that is so.

fc3schick87

iTrader: (1)

um, the fuse is popping. i dont have side illumination any more because of my body kit, i removed them. but my blinkers work and tail lights light up when i press the breaks

the night time running lights (tail lights) dont work, they pop the fuse. i replace the fuse. and they work for a few min . then the fuse pops again..

obviously there is a short some where.

the common problem your talking about, does it involve popping a fuse?
if this is a common problem i'd like to read more about it. but the search feature is a bit difficult to use, and to actually filter threw 100's of posts about "tail lights" so please, let me know

fidelity101

iTrader: (11)

fuse is popping due to a short. Power is touching where it shouldn't (ground)

fc3schick87

iTrader: (1)

yep... so i need to locate it.

i have my multimeter ready. and a back up plan if i cant find the hidden ground.....


i just need some pointers on how to actually find the short, if thats possible.

or simply how to use the multimeter to test for the short. not sure how to actually use the multi-meter to find a short. only for identifying wires and checking ohm and volts ect.

cone_crushr

iTrader: (18)

You need to isolate the various wiring circuits to locate the short (generally by separating connectors). However the first thing to check is - what did you do with the side marker socket when you installed the bodykit?

fc3schick87

iTrader: (1)

the front side markers were re-directed into the "jdm" flash to pass lenses. or the "city lights"

the connectors are identical, so i just used the side marker plugs for the flash to pass lamps.


i am in the garage right now running my hands over all the wires that i did have to modify, if any.

i can turn on and off the lights with a new fuse in there. but if i leave them on for to long, the fuse pops.

im going threw all the bulbs and connectors to see if anything looks odd. but right now im not quite sure what to do with the multi-meter, i mean i already know theres a short.

Hazard15301

iTrader: (5)

It's a pain in the ***, for sure, but you do need to isolate circuits and test from there. Try unplugging one bulb at a time and turn on your lights, etc. When they stop blowing fuses you've found your culprit.

fc3schick87

iTrader: (1)

so i found a loose connector. and i re-wired it. i think i might have been getting some arching in the crappy tube style connector. the wires were loose inside of this connector. so i cut, cleaned, and used better connectors on this splice in the illumination harness.

i had the illumination on for 15-30 min. the fuse didnt break.


i have to go out and drive the car to see if any bumps or any road vibration causes the fuse to pop again.. because that night i drove home a fuse worked for a while. but popped again while driving



so what do you mean by "test" the circuits by isolating them. how would i test them with the volt meter? im still trying to get a step by step on how to use a volt meter on how to test the wire between clips....

the bulbs, i already visually inspected non have tarnish or corrosion or bad filaments or anything.

HAILERS2

The Brake lights are not connected to the Tail lights or the side marker lights in any way.

Usually this is a common problem on this forum. Someone writes a thread saying his side marker lights and tail light don't work and neither his dash meter lights.

The normal fix for this is that the HEADLIGHT switch connector has a problem (and or the switch itself) and can be found by looking into the headlight switches electrical plug and seeing the green/white wire being burnt along perhaps with the red/black and red/green wires being burnt.

To prove this is or is not your problem, all you have to do is pull that plug off the switch. Then jumper a wire b/t the green/white and the red/black. That should turn the tail lights and side marker lights on. No key required. If the fuse (illumination) is good the lights should stay on and not pop.

That's what I'd do with a stk car. But you've been splicing and dicing the wiring....so I don't know what is wrong.

This *no tail lights, no side marker lights* is such a common problem on this forum and happens on a monthly if not weekly basis for the last ten yrs.

I wouldn't do it with a meter. To do it with a meter you'd have to disconnect each light bulb connector in the circuit and then put a meter on ohms and see if the green/white reads to gnd. By all bulb connectors I mean the ones in the combination meter, radio, clock, elec control switch, CPU in other words everything listed on page 50-54 of the free online wiring diagrams.. I am NOT suggesting you do it this way.

fc3schick87

iTrader: (1)

i only spliced 3 wires due to a corroded clip for the front passenger blinker. it was not working because the clip looked all tarnished and nasty. so i cut it and used connectors of my own.

your saying just bypass the fuse with your own wire into the fuse box, for the illumination circuit? but what if you have a serious ground. wont you cause a fire possibly from the arching of that wire? or heated up wires in the harness? the fuse is inline for a reason to prevent things like that. i wouldnt recommend adding a wire into the fuse box to jump the fuse. i'd only do that as a "test" but i already knew the fuses were being blown.

so there is no real way to use the multi-meter other then to use the ohm setting and go from one clip to another and see the readings? if there is a ground. what will the ohms read? i guess i'll have to test this out for my self with a good wire and a self made grounded wire hu?


theres the answer to my question. this wasnt just another stupid "my tail lights arnt working " thread. this was a thread asking how to use the multi-meter to fix the issue.


i havent really gotten a real nice answer from any one that posted. i tried to state my question clearly in the FIRST OP.

i can use plan a and fix the issue. or plan b and create my own circuit. i rather fix the issue prior to "bandaid" or "redoing"

HAILERS2

Only by removing all the light bulbs in the circuit will you be able to use a meter set on ohms.

Why? Because all the filiments in the light bulbs go to ground. So if you put the meter on ohms and do not have ALL the light bulbs removed.........the meter will show gnd and prove nothing at all.

The bulbs are not only at the tail and side lights but in the interior also.

I was suggesting installing a good ILLUMINATION fuse. Then pull the electrical plug off the headlight switch.

Jumper a piece of spare wire b/t the white/green wire and the plug and the black/red wire in the plug. Lights should come on at the tail and sides.

IF the fuse does not blow the problem lies in the switch or the short harness to the switch. Adding aftermarket lighting could have caused the switch to go bad.

IF the fuse does blow.......the problem is not in the switch but you have to remvoe ALL the bulbs shown in the attached jpg that are connected to the red/black wire. See jpg

HAILERS2

If you go to the red/black wire that was connected to the headlight switch and put a meter on the red/black................and the meter on OHMS........the meter will show continuity or something like 0.1 or 0.4 ohms as an example. The other lead of the meter goes to a known ground point. The chassis usually makes a good gnd point. Bare metal part of the chassis. Or threaded stud.

But if ALL the bulbs are removed the meter will read open or no continuity showing there is not short to ground. Then you might have someone watch the meter while you shake/move the connectors that went to the light bulbs and see if the reading change. If there is a short it will show up momentarily as you shake the harness. Most meters have a sound/horn that goes off when the circuit goes to ground. That's what is meant by ringing out a harness........the meter makes a ringing sound when the meter reads a short/ground.

If it were me I'd do what I suggested in the other post of mine. Pull the headlight plug off.........jumper a wire b/t the white/green wire and the black/red (with a good ILLUMINATION fuse already installed in the interior fuse box) and then see if that causes the ILLUMINATION fuse to pop or not. Then take it from there. I bet the problem is in the switch/small harness.

HAILERS2

No, only using the ohms feature will fix your problem. Voltage setting on the meter will do you no good. No way.

There's a lot of light bulbs in that jpg I attached. EVERYONE would have to be pulled..........unless you disconnected the Front to Rear harnesses from each other then you would not have to pull the light bulbs in the rear half of the car and you could then remove all the bulbs that are NOT in the rear of the car and ohm out the black/red wire to see if it's shorted to gnd. But if that checks out alright.......then you'd have to get on the black/red wire in the front to rear harness connector and remove all the bulbs in the rear of the car and ohm it out to see if it's shorted to gnd.

HAILERS2

I'll stop posting on this thread and let the fellow who suggested using a meter answer you question. I must be misunderstanding you. Gone

Cratecruncher

Another way to isolate a short with a multimeter is to use it in-line in ammeter mode. When I say in-line I mean that all the current must travel into the multimeter by disconnecting the circuit and putting one probe in one connector and the other probe in the other. The meter "bridges" to make the circuit. I like to place the ammeter in-line at the first branch of the circuit from main battery circuit (usually this is at the fuse location itself) . I measure the amperage and compare it to the fuse rating. (Your circuit amperage is obviously too high because the fuse blows but it's still good to have as a reference.) Next, I disconnect the harness connectors ONE AT A TIME and retest the amperage on the circuit. This will help you establish the general area that the short is located. Once you have isolated the problem to a harness you continue testing amperage by removing individual bulbs and inspecting the wires for obvious indications of heat damage. All that current is going to heat things up in a small isolated area which will often help you find the point of contact.

Since you have done a lot of modifications to your lights it is possible you don't have a short at all but have simply added too much load to the circuit. For example, a 3 watt bulb will draw 1/4 amp. A 6 watt bulb draws 1/2 amp. Multiply that times the number of bulbs and you may be just over the fuse limit (and the wire rating). (Watts = Volts X Amps) Hope this helps.

revox7

iTrader: (17)

my brother had this same issue turned out that the guy who installed the stereo had the wiring go from power to power and ground to a switched power basically the switched power acted as a ground but when the headlights were turned on power shot through the ground and fried the fuse

im sorry if this sounds confusing but thats what was going on with my brothers car