Wet Alternator?

[H.M.]

I just got a 90 Accord Ex with 190k miles. It’s well maintained and I’m happy with it.

I cleaned the engine per the instructions here and everything was good. But the NEXT morning I got a battery light. The battery was fully charged but the voltage didn’t increase as the engine revved. Bad alternator, right?

I tried keeping the hose away from the alt, distributor and fuse box but I’m guessing cleaning the engine had something to do with the battery light. CAN water kill the alt? And is there a way to dry it out, maybe use a moisture displacer like WD-40 to bring it back? Or is it just coincidence and the alt just happened to die the day after I washed the engine?

I checked and cleaned the connections to the alternator and didn’t see anything weird. Also checked the fuse box and other electrical connections looking for a stray bit of water. I’ve got the hood up now and am letting the sun bake the engine, hoping it will dry up any other bits of moisture.

[Ghostyman]

Which instructions did you follow? Did you check the belt? Did you hose the alternator while the car was running?

[H.M.]

Alt belt is ok. I tried to keep the water away from the alt, dist and fueses, but I'm sure they got wet.

I left the engine running while washing and the car never died. Drove it back to work and then later in the day drove it home ok.

Next morning got the battery light.

The engine washing thread is here:
http://www.cb7tuner.com/vbb/showthre...t=engine+clean

[accord91lx]

i dont think leaving the battery hooked up, and engine running while washing was a good idea. You probably should have removed the battery, washed it, let it completely dry, THEN hook the battery back up...but whats done is done.... take your alt off and take it in get it tested..that will tell the story.

[xaxis360]

You might have hosed your alternator.. no pun intended. Water and engines do not get along well. True, our engines can usually handle a wash here and there without any problems. But remember: washing an engine while it's on is BAD BAD BAD! Maybe it was good practice in the 50's but our cars have a bunch of sensors under the hood. Keeping those sensors active while spraying water can cause a short which will fry things like the ECU and other electronics. You are going to have to remove the alternator and take it to Auto Bone or somewhere for a test. If it is okay, you may have disrupted the voltage regulator. Our alternators can go bad from 150,000 miles and up so keep that in mind. If you do have to replace it, use genuine Honda or re-manufactured Honda whatever you do, dear Lord! Don't get me started on aftermarket here...

[Ghostyman]

You should not have washed the engine while it was running. It is safe to hose down the alternator while it is off, but you can (and probably did) damage it by heavy spraying while it's running.

There seemed to be a lot of misinformation on that engine cleaning thread. A method that is considered safe is this:

1. Start the car and let it idle until it is warm.
2. Turn the car OFF.
3. Spray the engine and bay with Simple Green degreaser. Let it sit for 10-15 or however long you think is appropriate.
4. Hose down the engine bay with a hose.

Important things to note: DO NOT use a high pressure sprayer. It can force water past seals, especially on older cars like ours. I don't use a nozzle or anything that narrows the hose stream.

After you've degreased it, I've had good luck covering the entire engine bay with tire cleaning foam and letting it do it's magic. A water rinse is optional.

[H.M.]

Thanks all, sounds like I probably trashed the alt by getting it too wet (though I did my best to keep it and the other electrical components as dry as possible.

I'll get it tested, probably shop for a new one this weekend.

Guess I shouldn't have gotten so excited about cleaning the engine but I read that thread six times and thought others were washing it with the motor running.

[SoapyToast]

When you said the voltage changed as you rev the engine, its a sign that one or more diodes have gone bad on the voltage regulator. I found out because the exact same thing happened to me. A good working alt will keep the voltage from exactly 13.5v to 14.0v. Mine would vary from 12-13v at idle and go upto 14.5v. Mine died because of the same reason, I had washed my engine bay a few months ago. Old alternators just can't handle water at all.

[Ghostyman]

Yeah, in the future just do it with the engine off.

I'm not even sure why people think it's a good idea to do it with the car on.

[deserthonda]

as it was stated ,,,your alternator is toast ..electricity does not like water ..

[bruno8747]

Go to pepboys or an auto store and get a can of CRC Electric Clean or something similar and spray it into the alternator and let it dry out. And then see if that helps. That normally washes away any dirt thats in there and MIGHT help you. Its only a couple of dollars for a can.

[H.M.]

Thanks all. Replaced the alt last weekend. Was able to do it without removing the power steering pump. A little tight of a fit but doable.

The electric clean tip came in after I was already done.

My engine bay now looks pretty clean, but the new alternator is the cleanest component in there.

[xScott]

hmm....