electrical/starter problem

kr8zstang

New Member
Nov 3, 2005
53
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upstate, sc
the last few weeks, my battery has been dying overnight. battery is new, alternator checks out good. if i jump start it, it runs fine and will restart all day. well, today i try to jump start and the starter turns slowly, so i turned the key off, but the starter continued to turn. then the starter slowed down and stopped. now i have no power anywhere in the car. what the heck? what are some possible causes? thanks
 
The battery ran down, and when you jumped it the second time, the starter solenoid contacts welded themselves and stuck closed. Remove the solenoid, carefully making note of where the wires are connected. Then smack the bottom of the solenoid hard with a dead blow hammer or a block of wood and a regular hammer. That may unstick the contacts.

Once you have either unstuck the contacts or replaced the solenoid, follow the checklist if you are still having problems.

Here's a checklist:

Since some of the tests will bypass the safety interlocks, make sure that the car is in neutral and the parking brake is set. Becoming a pancake isn’t part of the repair process…

Check battery, terminal connections, ground, starter relay switch (also known as solenoid) and starter in that order.

A voltmeter is handy if you are familiar with how to use it to find bad connections. Measure the voltage drop across a connection: more than .5 volts across a connection indicates a problem.
See http://www.fluke.com/application_notes/automotive/circuit.asp?AGID=1&SID=103 for help
fig-7.gif


1.) Will the car start if it is jumped? Then clean battery terminals and check battery.

2.) Check the battery to engine block ground, and the ground behind the engine to the firewall.

3.) Jump the big terminals on the starter relay next to the battery with a screwdriver - watch out for the sparks! If the engine cranks, the starter and power wiring is good. The starter relay is also known as a starter solenoid.

4.) Then pull the small push on connector (red wire) off the starter relay (Looks like it is stuck on a screw). Then jump between the screw and the terminal that is connected to the battery. If it starts, the relay is good and your problem is in the rest of the circuit.

5.) Remember to check the ignition switch, neutral safety switch on auto trans and the clutch safety switch on manual trans cars. If they are good, then you have wiring problems. See http://www.autozone.com/images/cds/gif/large/0900823d80195963.gif for 88-90 year cars .OR see http://www.autozone.com/images/cds/gif/large/0900823d80195964.gif for 91-93 year cars. See http://www.autozone.com/servlet/UiB..._us/0900823d/80/1d/db/3c/0900823d801ddb3c.jsp for 94-95 model cars.

6.) The starter may be hung, loosen up the bolts that hold it on, and give it a good whack with a big hammer. Tighten up the bolts and try again.

7.) If that doesn't work, use a jumper cable from the positive lead on the battery direct to the starter post where the big wire from the relay connects. If it cranks then, it is the power wire from the relay gone bad. This will be hard to do, since there isn't much room to do it.

8.) Pull the starter and take it to Autozone or Pep Boys and have them test it. Starter fails test, then replace it. If you got this far, the starter is probably bad.
 
kr8zstang said:
could a short somewhere cause the battery drain?
Absolutely. You can use your meter to isolate which circuits are the cause, and dont forget about the alternator - a bad diode can allow voltage to drain while the car is off. It is easy to forget to check that.

JR will have much more info. Good luck.
 
kr8zstang said:
could a bad starter relay cause my battery drain?
If the contacts stick closed, it would run the battery down quickly. Use an ohmmeter to measure the resistance across the two big studs. You should see an open circuit (infinite resistance) or greater than 100 K ohms.

Troubleshooting battery runs down overnight problems:

Typically it is something draining the battery. Small things like glove box or courtesy lights are often the culprits. If you have an aftermarket stereo or alarm system, it is also suspect.

The ideal method is to disconnect the positive terminal, and connect a Digital Multimeter (DVM) between the positive terminal on the battery and the positive cable. Set the DVM on a low current scale of 2-5 amps if it doesn't auto range. Watch the current draw, and then start pulling out fuses. When you see a sudden drop in the current, that circuit is the likely culprit. Note that the computer, radio & clock will draw less than 1/10 amp to keep the settings alive.

See http://assets.fluke.com/appnotes/automotive/beatbook.pdf. You will need the Adobe Acrobat viewer which is also a free download – http://www.adobe.com/products/acrobat/readstep2.html