Weird electrical problem on 2005 Civic

[mmntech]

Every problem I seem to have with anything is always weird. Seems my 2005 Civic is no different.

I had shined up my engine bay the other day, then got in to drive it. Noticed that the ABS, airbag warning, and break warning lights were on. They only come on when I rev the engine, and go off when I'm breaking, stopped, or driving over about 80km/h. Sometimes the break and ABS lights flicker on and off while I'm cruising.

There doesn't seem to be anything wrong with these systems. So I talked to the mechanic next door to where I work. He seems to think its the alternator but needs to test it to be sure. I'm talking it in on Friday. If it is, that's not going to be cheap. I think maybe some water got into a connection or I inadvertently knocked a wire loose.

The car only has 48,000km on it. I don't drive that far back and forth. It has been maintained and it does have a newish battery. It's the 4 door LX-G model with auto trans.

 

[Zargon]

I dont know WHY the alternator would cause that.

but I dont know that much about civics and their quirks, I would check the harness at the ECU though since that controls most of the warning lights(in my experiences)

 

[slag]

Going with alternator as well. When the alternator doesn't produce full output, often times it can cause sensors and other electrical devices that rely on full power to give incorrect readings. You can test this yourself by buying a cheap multimeter and probing your battery's connections. You should see 13.5-14 volts at the posts. If less, your alternator isn't doing its job and causing issues. I've seen it where the alternator or charge light isnt on, but the alternator isn't working properly.

 

[mmntech]

Ah, that seriously sucks if the alt is indeed going. I'll check the voltages this afternoon.

They're not as expensive as I thought though as long as I stay away from Honda Genuine parts. How big of a job is it to replace one. Not that I'd DIY it, just trying to figure out how much it's going to cost me.

 

[Zargon]

all depends on where the alternator is located.


if the belt is loose it can mimic a bad alternator and cause other issues

 

[mmntech]

all depends on where the alternator is located.


if the belt is loose it can mimic a bad alternator and cause other issues

Could be the belts. It's due for it's 48,000km maintenance, which includes adjusting the drive belts.

The alternator isn't hard to get it. It's under the air intake but certainly not as tightly packed in there as the newer Civics are.

 

[Zargon]

then its not bad, I've done them some on some cavaliers, my old SC2, my jeep. all were childs play as you didnt have to dig for the alternator, undo the belt, undo a few bolts and the wiring plug on the alternator, then redoit

now starters are another story

 

[AMCRambler]

Before spending all that money, try cleaning the battery cable terminals and posts with a wire brush and snugging them down good. Could be a loose connection. You could have knocked a cable loose cleaning your engine bay.

 

[mmntech]

I checked the battery and it's indeed low. Just hovering over 12.5-12.75v.

 

[alexruiz]

I had shined up my engine bay the other day, then got in to drive it. Noticed that the ABS, airbag warning, and break warning lights were on. They only come on when I rev the engine, and go off when I'm breaking, stopped, or driving over about 80km/h. Sometimes the break and ABS lights flicker on and off while I'm cruising.

What do you mean as "shined"?
You mean as washing it? hose sprayed, pressured washed or just wiped with a cleaner?

Sensors and all the sensitive devices are fed by voltage regulated outputs through the modules (ECM, TCM, ABS, etc) They can also operate in voltages as low as 9 V.

I am suspecting your "shining" messed with the connector in a device. Which one? I don't know, but it seems the serial bus is acting weird (HS CAN likely)

 

[mmntech]

What do you mean as "shined"?
You mean as washing it? hose sprayed, pressured washed or just wiped with a cleaner?

Sensors and all the sensitive devices are fed by voltage regulated outputs through the modules (ECM, TCM, ABS, etc) They can also operate in voltages as low as 9 V.

I am suspecting your "shining" messed with the connector in a device. Which one? I don't know, but it seems the serial bus is acting weird (HS CAN likely)

Hosed out the winter salt then polished up the plastic covers with a light plastic cleaner. That's why I suspected water might have gotten into something it shouldn't have.

Let's assume I'm a noob at this. What connections should I be looking at.

 

[slag]

I checked the battery and it's indeed low. Just hovering over 12.5-12.75v.

One glaringly large omission I left out was that this is the voltage you should see when the car is running and charging the battery. Did you take the reading when the car was on?

 

[Eli]

I checked the battery and it's indeed low. Just hovering over 12.5-12.75v.

That's not low. 12.7V is fully charged for a flooded lead acid battery.

One glaringly large omission I left out was that this is the voltage you should see when the car is running and charging the battery. Did you take the reading when the car was on?

That is incorrect. He should see ~14.0V when the car is running.

 

[slag]

That's not low. 12.7V is fully charged for a flooded lead acid battery.



That is incorrect. He should see ~14.0V when the car is running.

I agree with you. Reread my original post. I posted a reply that the 13.5-14 volt reading should be with the engine running.

"You should see 13.5-14 volts at the posts."

 

[Eli]

Oh, I see.. My bad. Just your wording made me think you were responding to his post where he mentions 12.x volts.

 

[slag]

Oh, I see.. My bad. Just your wording made me think you were responding to his post where he mentions 12.x volts.

yeah, i wasnt clear and my post was ambiguous. at least we are in semi agreement

 

[mmntech]

So yeah, my mechanic says the alternator is toast. Ran the test. It's putting out 18V+ with no load, which is apparently way too high. So basically, it's overcharging everything.

Any good third party brands out there? They want me to go Honda OEM but those things are like $300 plus labour to install.