Help? Alternaor/electronical Problem

[RED LXI]

I DON'T KNOW WHAT THE HELL IS GOING ON...my alternator is only charging after my check engine light comes on.(which never used to happen). It seems like there is a short somewhere because the battery light is not coming on. Once I hit a bump in the rood after the battery light has been on, them all of a sudden the alternator works at full power. What could be causing this problem. unless my battery is at full charge when I first start the car,(depending on how long it takes the check engine light to trip)it will kill the battery dead before the alternator kicks in. this is crazy.... help please.......I've checked the clip on the alternator nad all the connects and wireing seems fine.

[soljaboy2000]

check you battery conections and wires

[RED LXI]

i don't know if i'm checking the right wires or what, but the connections seem to be nice and tight. does the altenator have a relay or electonically controlled switch that tells it when to give charge; because ive noticed that if I take off my battery terminal before the check engine light comes on the car shuts off, but once the check engine light is on it keeps running.

[nswst8]

Main relay box under hood #21 Alternator
Fuse box under dash #8 fuse
Your Alt could be going bad, Diodes, stator
Hope this helps
NSWST8

[Blkblurr]

How many miles on the alt? Most likely the brushes in your alt are worn.

[RED LXI]

the alt does not have that many miles on it. It is a rebuilt alternator out of an 89 legend. If the brushes are worn would the alternator work at full power when it does come on? Thats the only reason I think the alternator is still good , but I could be wrong.

[RED LXI]

I don't recall seing an alternator relay, is the main relay the same thing?

[cruznz]

what code did the ECU give?

[nswst8]

Under the relay box under the hood next to the battery, look under cover for location of relay (Alt)
The main relay (fuel) would let the ride turn over, just would not start do to no fuel.
Still convince the silenoid (starter) or "alt" is bad
Hope this helps. LOL
NSWST8

[Blkblurr]

Yes the alt could give you full power if the brushes are bad. When they wear, they do it gradually. Once they get to the point of bad wear they make contact with the commutator ring intermittently. I think this is what you may be seeing. I don't think the starter solenoind is it because it has nothing to do with the alternator charging or not charging. I think the bad alt is causing the battery problem. I could be wrong though but my experience and background in electronics tells me this is the problem.

[RED LXI]

what about the check engine light is that supposed to come on? and the alt works fine after it comes on. Isn't my battery light supposed to come on if the alt is bad, the last time my alt went bad the batery light just stayed on.

[RED LXI]

I have yet to spot the damn alt relay............Its getting dark so i guess no school or work tommorow.

[accordlxi2.0]

on our car's (lx-i , se-i ) there is a wire that runs from the alt to the ecu.
what is the code?

[RED LXI]

Update: I must have fu*#@!$ bad luck.... Today I got a brand new alternator put it in and this time the damn battery light just stayed on; and its still not charging. I could find out what was wrong , after the mechanic troubleshooted and assured me everything was done right, the only thing we could think of was that the (brand new) alt does not work. However the parts store could not deliver the replacement before the mechanic shop's closing time. How in the world can a new alt not work. Has anyone gone through this before???? This is crazy. I had to go back and put the old one back in so I can get home, but its still doing the same thing just that the battery light isn't coming on. Guess I'm stuck until Monday.

[RED LXI]

upddate again.... Now I know for sure that it is not the alternator. The new alternator is in now and my battery light comes on sometimes whenever I shift gears or turn a corner. I know it is not the clip on the alternator or the ground wire. So I guess I'll have to find a way to check my wires running from the alternator to the battery. I've also noticed that there is a wire running from the battery to the fuse campartment under the hood,............the end of the wire in the fuse box has a screw into a piece of metal,............the screw is tight but i can move the metal wiht my hand, Is this right? could this be causing the short. If not where else should I look?

[Blkblurr]

Check the fuse that your alt feeds into. I don't have a fuse number but i think it's a 40 amp fuse. This may be loose or corroded. If your alt light is coming on, power from your alt is not getting to the wiring harness ie: the battery or any of the circuits downstream of the alt and battery. Your test proved this when you said that the engine would stop if you pulled the battery cable off when the alt light was on. This means no power from the alt. You may have a loose power feed to the alt as well. It takes power to make power on the alt. You have stator coils to power on the alt. If this wire is loose or broken (goes to the alt) you will not produce any power from the alt. No! there is not an alt relay that controls charging. If you have a service manual, look at the wiring diagram in the charging section. Look at the fuses connected to the alt circuit and check them for tightness and good connections in the fuse box. The only other thing it can be is a broken wire that makes intermittently.

[RED LXI]

thank you Blkblurr for the vital info, this weekend when I get some time, I'm going to retrace all those wires comming fron the alt or to the alt to check for a short. I've been looking for that alt fuse and i can't find it anywhere, does anyone have a picture of alternator wiring diahgram?..If anyone does it will be greatly appreciated.

[Mac]

It sounds like something is loose. The fuse for the alternator should be in the fuse/relay box under the hood by the battery. It should be about a 70 amp fuse. It looks like a piece of metal with a plastic box in the middle held down by screws. Make sure it's tight. Check the connections on your battery, they should be clean and tight. Also check the other end of the neg. wire where it hooks up, again make sure it is clean and tight. Check all the ground straps on the car the same way.

[Blkblurr]

Hey RED LXi. Check your pm's I have a file to send you.