I recently replaced the whole radiator assembly and everything was running smoothly. No problems starting whatsoever. I noticed the acid was already coming out of the terminals on the battery so I decided to clean it. I have an alarm on the car that wasnt working before up until I cleaned the battery terminals which might have given it a better contact point since the wire off the alarm is directly hooked up to the battery. Then one afternoon I just couldn`t start the car, the lights, horn, power everything just don`t work. I had to jump start the car in order for it to start. I thought the battery was just in need of replacement so I bought a deep cycle red top optima. I replaced the battery and it started fine the first time until I turned the car off and tried turning it back on and it wouldn`t start. I had to jump start the car every single time for it to start. I have a multimeter so I decided to jump the car again and see where the voltage is at after starting it. It`s at 14.6v. I thought the alarm might`ve been setting it off so I pulled one of the fuses for the alarm and it stopped working. How do I pinpoint the short with my multimeter?

 

Test the wires related to the alarm for voltage, and then compare to the alarm instructions to see which wires are supposed to have constant power. Also check the ground and make sure it makes good contact and isn't draining power.

 

When doing multimeter tests check your voltage drops from your alarm back to your power source. Where ever voltage stops showing, between that point and your last positive voltage check, is where your short is. If you can see the supply wires to your alarm package try to test the voltage input at the alarm. Im betting its a bad ground though. But if the power stops somewhere along the supply side than that might explain your battery draining. The circuit (if there is a short) is causing the batter to constantly discharge. My bet is a bad ground wire though. Most ground wires become corroded and even if they are looking to be in perfect physical contact they might not be electrically connected. If your battery is constantly dying that means a circuit is always closed in your car which is causing a constant drain. In my 93 lude my alarm announciator ground was pinned between my clutch fluid resevoir and my body and eventually the corrosion was soo bad it had no continuity at all. I removed the wire, restripped it, sanded a point on the body which showed only metal, and rebonded the wire to the body. Works perfect now.

 

so if i connect 1 lead of my ammeter to the batter y adn another lead to a disconnected battery cable and i see current then there`s a parasitic load? then i disconnect fuses by fuses and see if the same curretn i was reading is present there with the battery negative disconnected? is that a good process?

 

car only start when i jump it. otherwise as soon as i take the jumper cables off and i turn the car off and try to restart it, it doesn`t start at all

 

check your battery terminal to post resistance /voltage drop, your wires that clip onto ur battery terminals may be rusty.

put 1 wire on the post on ur battery, and put the other on the wire that clips onto your post

 

ok so the battery checks out fine, changed the negative battery cable because it was corroded, changed the alternator and the belt. still the car woould only start when you jump start it.

 

up

 

help

 

ttt

 

ttt

 

did you check for parasitic draw? here's what you do, put your dmm in the ammeter mode and hook it up in series with one of the batter cables, meaning you disconnect it and put the meter in between. if the parasitic draw is over like 5mA, you need to look around for the draw. you usually do this by pulling fuses until the draw returns to normal. find the component thats causing the problem(usually a light that doesnt go off when it should, ie: trunk light). if that's not the problem i would definetly look at your cables going to the alternater and battery. if they are corroded they arent going to be good conductors.

 

bump cause im having the exact same problems

 

positive battery cable wsa the problem after a continuity test with my ohmmeter.. i just dont understand why it would start when i jump start it. I mean it's not like im jumpin it straight to the starter terminal, im jumpin it on the battery terminals. If power can't go through from the battery to the starter because of the faulty positive cable, i dont see how it would start but problem fixed.

 

hmmmm interesting i need to get a multimeter

 

yeah here are some tests you can do:
parasitic draw, go to ammeter mode/current tester, disconnect the negative cable. connect leads from the positive terminal to the disconnected negative cable. if it shows that there`s more than .005 then you have a short somewhere, start pulling fuses with the battery negative cable disconnected and place the leads where the fuses would be at and see if you get the same reading you got before.
switch to ohmmeter with the battery negative cable disconnected at all times so you don`t blow the fuse in your meter. measure for continuity from one end of the negative cable to the other end and do the same with the positive cable.