89 Accord F/I Charging Problems?

[Jon_2121]

I've had a problem for the past several weeks with my 89 Accord LXi. I recently replaced a battery (unneccessarily) and alternator (was blowing out black crap). Five days of daily driving since replacing the alternator and recharging my battery from initial alternator issues, my battery dies. I noticed on the drive home that the alternator keeps the engine running just fine, however it seems the circuit that is supposed to charge my battery is weak or not working off and on. I noticed on a few occassions a slight power loss, but no stability loss in the engine electrical firing. However, during these times the power windows would creep up and down when I tried them and the A/C would blow out significantly warmer air, then all of a sudden the power would "kick back in" and everything would operate just fine accessory-wise. Obviously when I got home I immediately shut off the car and tried turning it back on suspecting the battery to be dead and it was.

The problem has nothing to do with how long the battery sits or anything of that nature; It started after 2 days of sitting prior to this and started just 3 hours after shutting the car off before the ride home. However, it wasn't really noticeable with the power loss until the battery was fully discharged apparently, as I had freshly charged it before alternator install, I guess it was slowly draining it with my accessories ever since. Does anyone have any suggestions as to what is going on or what I can check/do about the alternator/charging circuit not wanting to keep my battery charged/maybe what caused my other alternator to fail on me, etc.? Again, the wiring is pretty old, but with little to no corrosion on the connectors themselves, however I have not ruled out the entire connection from alternator back to battery, including the relay and fuse box. I need a cheaper solution than paying a dealership 89+ dollars an hour to look into and replaceing the wiring.

A friend of the family suggested replacing or testing the new alternator before I even look at the wiring because he is not a fan of Auto-zone alternators and parts. However, to me it doesn't seem like the alternator or voltage regulator inside is necessarily bad, afterall, it is brand new, I did install it correctly, and it does keep the engine running for as long as there's gas off a jump, it just doesn't charge my battery back up in-between.

[jeffcoslacker]

How sure are you of the battery's condition? If the battery has lost water from all the charge/discharge cycles it's been through, that can cause the regulator to shut off charging intermittantly...

The primary wire that charges the battery from the alt is easy to spot...it's a fatty wire running back to the positve side, can't remember if it goes directly to the battery on those or to the power distribution box there but it's real easy to spot and trace...make sure it's solid all the way to the alternator.

Check charging output at the charging terminal on the back of the alternator...should see 14v or so there at idle...if you see less at the battery then that wire may be bad, if you see the voltage cutting back at the charge terminal then the regulator is commanding the cutback, you have to find out why. Check the wiring for the regulator carefully for soft spots or burns.

Some older ones would fry the wire from the regulator to the ECM, and the ECM would get an incorrect or intermittant voltage reading and signal the regulator to cut back on output...

A shorted battery will make the reg cut back also...but shorted batteries usually will fail to start and reject a jump/charge from time to time and then suddenly start working fine...