Alternator or Battery Problem ???

So I went to AutoZone and they checked my battery and alternator with a mchine that attaches to the battery terminals and they told me both were fine. Well I'm not sure if I believe them...

Here's what happens with my car:

  • sometimes fails to start, but the dash lights come up.
  • when idling sometimes the power to AC, radio, and transmition gets cut off.
  • when starting from a stop sign, same as above, and car jerks a bit.
  • the remote key doesn't always work, and when it does, the "beep" when locked is more like a "mooooo".
  • basically it seams like there's not enough juice, but it doesn't happen ALL the time.

Here's the kicker: it all goes away when the AC is off.

So what can it be? I checked the fuses and connectors around the battery. All look fine.

Reply to
mvorbrodt
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First, at no cost except your labor, remove, clean, and reconnect cables. They can look fine--even be so tight you cannot remove them w/out a wrench, and yet not make good electrical contact. Then, check further if you find there exists a problem. HTH, s

Reply to
sdlomi2

Sounds like a short somewhere. When I got my car the doors would lock and unlock by themselves at erratic intervals. Turned out to be a bad car alarm wiring job. Loose connection. If nobody has reworked your factory wiring, could be a bad harness. You have to isolate the circuits causing problems and go from there. Start by making sure everything visible has a tight clean connection.

--Vic

Reply to
Vic Smith

wrote: Alternator or Battery Problem ???

Here's what happens with my car:

___ sometimes fails to start, but the dash lights come up. ___ when idling sometimes the power to AC, radio, and trans cuts off. ___ when starting from a stop sign, same as above, and car jerks a bit. ___ the remote key doesn't always work, and when it does, the "beep" when locked is more like a "mooooo". ___ basically, it sems like there's not enough juice, but it doesn't happen ALL the time. ___ the kicker: it all goes away when the AC is off.

AutoZone checked my battery and alternator with a machine that attaches to the battery terminals and they told me both were fine. So what can it be? I checked the fuses and connectors around the battery. All look fine. ________________________________________________________

It does sound like a bad connection somewhere.

You can't tell the quality of the connections by looking at them. You have to disconnect every connector, inspect and clean it, then reconnect it. This includes:

Pos Cable to Pos Battery Post Pos Cable to Start Relay Terminal Pos Cable to Fusible Links. Pos Cable to Alternator Terminal.

Neg Cable to Neg Battery Post Neg Cable to Engine Block Engine Block to Chassis Cable

Try these, then post again noting the results and identifying the vehicle. You may get more help.

Good luck.

Rodan.

Reply to
Rodan

OK, so I disconnected the battery and cleaned the connections with a wire brush. Still having problems.

Now, I started the car with AC off, and disconnected the battery negative terminal. It started to chocke a bit, but still ran. Then, with neg. disconnected, I turn the AC on, and it died. So I reconnected the neg, turn the AC on, and started the car. Then i disconnected the neg. and it died instantly. I repeateed this 4 times with the same result.

I'm guessing alternator. You?

Reply to
mvorbrodt

Sounds to me that you are too stupid to do your own car electrical work. I have to say this about anyone who would remove the negative battery cable with the car running.

Reply to
zzyzzx

Probably is now. On most of the newer vehicles disconnecting the alternator for a few seconds is enough to blow the regulator or a diode or two. The catch is that on many of the vehicles built after 95-96 the regulator isn't in the alternator, it is inside the ECM. So if you blow it you get to replace the computer!

I would look for a bad cable or bad ground strap from the block to the chassis.

Reply to
Steve W.

So right, Steve. Ever notice they are often referred to as--not 'alternator'--but battery maintainer? Plus, doing the 'good samaritan thing' by boosting someone can blow your own alternator(or whatever they wish to call it), esp. if their battery is close to completely dead! sam

Reply to
sdlomi2

Link? I've never hear of the regulator being part of the computer. That does not sound like a good design either, sicne the regulatore is likely to throw off heat.

Reply to
zzyzzx

I believe GM still has the regulator internal to the alternator. In the previous years, they certainly did so. Heat and vibration are two of the main factors that kill regulators.

Chrysler and, I believe, Ford have at least some of their regulators outboard or in the ECM. They run cooler, in general, have less vibration, and are generally perceived to last better.

Reply to
HLS

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