No spark?what can it be?

[Cuda4play]

Ok,this has been pissing me off...My car has ate 3 batteries in a few months,before my 3ird battery died,i wasn't getting any spark.Can it be that my voltage regulator is out or the fusible link is out on the starter relay if i'm guessing right?also,i put in a new alternator..any replies are welcome.

[ehostler]

Most auto parts shops (KRAGENS) have analyzers that they will hook up to your charging system, to test it. They will normally do this for free, so they can sell you something.

Most of the analyzers are Bear scanners. They are very accurate for charging system diagnostics.

[71 scamp]

I agree, I had to do that before at Auto Zone.

[Cuda4play]

Thanks for the info,i'll give kragen a try heh

[Jims451]

If you have old battery cables, spend the $6 to $10 and replace them with new ones. This probbly is not your problem, but it seems alot of people overlook the condition of battery cables and connections and go straight to battery / alternator / regulator.

You will want to check if the battery is being under charged, over charger, or drained by a short in the wiring.
Possably the easiest to check for is over charging, with the engine running at a fast idle (probbly about 1,500+ RPM), check the voltage at the battery, it should be around 13.5 to 14.5 volts. If it is over 15 volts you probbly are overcharging the battery. If you disconnect the wiring from the Voltage regulator and it is still overcharging then there is probbly a short in the alternator feild connection or wire that runs to the Voltage regulator (on 1970+ with electronic regulator.) If you have the old points regulator, and the overcharging continues, it is probbly the alternator or someone bypassed the regulator wiring and put +12 volts directly to the alternator feild connection.

If the alternator is undercharging I would first put a jumper from the alternator output to the battery + terminal and see if that fixes the problem. This jumper bypasses the bulkhead connector and ammeter in the dash which could be bad. If that has no effect then:
On the older point regulator system, check for (or jumper) +12 volts at the feild connection (the other feild is internally grounded.) If the alternator doesn't start charging you may need a new alternator, if it does charge, the voltage regulator (or wiring) is probbly bad.
On the dual field (newer electronic rugulated system) one alternator feild should have a constant +12 volts from the ignition key, the other feild (ground) is controlled by the regulator. At the regulator the two terminal connections, one should be a +12 volts and the other goes to the alternator (this will show +12 volts also unless you disonnect the alternator feild wire. If you ground the one that goes to the alternator (and re-connect it)it should start charging (assuming that the other alternator feild has +12 volts from the ignition.)
If it charges then the regulator may be bad, but rember that the third connection (the pass through of the ground current) is the regulator case! So the case need a good ground. You may want to make a jumper wire to go directly from the regulator case to the engine block (there should already be a firewall ground to block connection?)
If no charge, then have alternator checked out.

OK, so everything still seems to be working. You may have a short or drain on the battery with the ignition off. With the ignition off you can remove the battery cable and put an ammeter between the battery terminal and the cable to measure current draw. Then pull the fuses from the fuse box. No current should be flowing? If it is, the alternator probbly has an internal short. Disconnecting the alternator cable from the alternator stud should stop any remaining current flow. If that dosen't do it and you are still pulling current, you could have an unusual short in the starter or wiring that bypasses the fuse box (ignition wiring at or to the key?)

[Jims451]

Sorry I din't address the spark issue, it may or may not be related to the charging problem.
If it is related, I would check the bulkhead connector, ammeter (check for +12 volts here on both sides), and ignition switch.

[Cuda4play]

That was the best explantion.My car usually drains the batteries when the car is off.I will take a look at what you said and apply it to my car.Thanks a lot Jim!!

[side note]
My battery is located in the trunk.

[Jims451]

My Charger has a trunk mounted battery too.
Battery negative is just connected to body at turnk, but body attachment point was cleaned and coated with an anti-seize compound that contained silver? I think this is helping to make a good connection and protects the surface from rust.
The positive battery connections goes to my Battery cutoff switch. From the switch the power cable (I got some used industrial, silicon insulated, nylon braided wire from my Brother in law for free) goes to the nuteral starting relay on the fender where it connects up simular to the original "short" battery cable. At the relay stud is the power that goes to/from the bulkhead connector, and a seperate cable for the starter.
To kill the engine with the battery cut-off switch, the cut-off switch has an ignition kill microswitch used with it that grounds the ignition negative side which works with a normal ignition setup, or in my case, it is the trigger signal to the MDS box that is being shorted to ground.

[Cuda4play]

cool,i'm just learning about cars,so it will take me a little longer to translate what your saying hehe.