[Jim69Mustang]

I have a 1988 ford mustang, its a Lx hatch back 4 cylinder 2.3l engine. I have a 830 cold cranking amps battery and have replaced my alternator with a 100 watt alternator because i have added a sound system to my car. The only problem Ive found that i have is my car will only crank up half the time and i don't know why. I drive the car all the time unless it doesn't crank up and just here recently it hasn't been cranking and i don't know if its because of the cold or what, it doesn't even click like its gonna start. Ive replaced the starter switch and the starter cylinoid as well as the battery cable. Could the starter itself only work half the time?? should i try replacing that??

Id also like to know if i can just bypass the whole computer system in the car and just put an electronic start or do i have to run it through the computer system?? If i have to can you explain it to me as to how to do this?

 

[vicrod]

The starter could have an intermittent problem, brushes are shot or an open segment on the commutator.

Before you replace the starter make sure the ground cable to the engine is good. Clean the battery clamp connection.

If you get 12 volts to the solenoid while attempting to start but the solenoid does not click, you have no ground or solenoid is bad.

Try running a jumper cable direct to the starter to rule out a bad solenoid.

The starting system in that car is not computer controlled.

vicrod

 

[docvette]

Doc here, imp:

First, I hope you mean 100 AMP Alternator..not WATT..

Not knowing what type of Audio System you have, (how much power is consumed, and how it is used, like sitting parked or driving) It's Hard to say if it is the source of drain or not. And the location and cable size is another factor.

Be sure the Alternator belt is tight.

Inspect and clean the cables for Corrosion, and be sure they are tight.

If the starter is not engaging when this happens (no clicks or noises) Check the neutral safety Switch for in-op or out of adjustment conditions. You can bypass it for testing. You can also try the "S" terminal to the battery cable bolt side of the solenoid with a screwdriver to see if it will crank, this all points to the NSS as a problem.

Start the Car, and let it warm up about 5 minutes or so, at warm idle, get your DVOM out and set it for V X 50 or autorange. Measure across the battery, it should read 13.95 to 14.4 Volts at idle, no load conditions. If not, you have an Alternator or regulator problem. Is this externally or internally regulated? (Not a Ford guy at all!) ..

Have the Battery Load Tested at the local Auto Zombie, for free, If it has a Bad cell it will fall off rather quickly, indicating your battery needs replacement..

Remember: EVEN new parts fail, a lot of times right out of the box! Do the testing FIRST..don't throw parts at it before, you probably won't fix it and it gets costly!

If your system is High Wattage amp and deck (like 1500 watts or so) You should upgrade your cables to 0/0 or 0/1, to avoid heat loss (and current drop) To the battery, as well as the cables to the amp (especially if located in the trunk.)

Check all your grounds. You should have one cable to ground AT or near the starter, to any handy bolt, from that same bolt, run another 0/0 to the frame. Also from that same bolt run a 10 gauge wire to the firewall and ground it. Also run another to the alternator Ground lug, and /or mount bolt. Everywhere you ground a wire, Clean, and Burnish off paint and dirt or grease from the area, and add a star and lock washer.

The starter motor could have a flat spot, but If , when this occurs, you can start it by jumping the "S" to the battery cable bolt, that will rule that out.

As far as bypassing the computer for start up only, I doubt that is a possibility, as it is all or nothing at all if it is injected , and has sensors that dictate haw the engine fires..I'd leave it alone anyway, If it is a road driver and your state has smog regs..it could leave you walking on your next biannual!

Doc imp:

 

[matt167]

The TFI coils were notoriouse for intermittant problems, and then just failing compleatly. I know a '88 2.3 has a TFI ( Thick Film Intergrated )

 

[Jim69Mustang]

ok well i have 1 350 watt amp. 750 watt amp. anda 1400 watt amp

 

[docvette]

Doc here, imp:

Well, there is your problem right there..

At FULL capacity, that's 2500 watts..if you apply a little ohms law at 12 volts, that's a draw of 208.3 amps at about 0.5 ohms..over twice the amount the alternator can cope with.

You must either scale back the system , or upgrade the battery / charging circuit to handle the huge demand on the system..

Doc imp:

 

[matt167]

do you have a capacitor? sometimes, you can get away with just running a 1.0 farrad capacitor or better, to help the charging system along, not to mention, the headlights won't flicker from the draw. but going full output on an alternator too much, will kill it.