I hate cars

Ill start the more in depth diagnostics tomorrow but I just confirmed I still have a charging system problem. Ill link my alternator replacement thread tomorrow but I recently replaced the alternator because the original was not charging; making a loud whining noise that would go away when I unplugged the wire harness, and would get very hot very quickly.

The brand new alternator charges but only puts out 12.5v. Above 6k rpm the charging light comes on. I figured it was belt slippage from the original hard belt that's getting replaced soon.

Tonight I was tuning the stereo with the engine off. After about an hour I decided to put the charger on it so I didn't run the battery down. The laptop I use for tuning displays battery voltage and it didn't go up when I put the charger on it. When voltage got into the 10s I decided it was time to start it while it would still start. So I started it and let it idle. Voltage was only 12.4v. The engine seemed labored. Voltage increased slightly with more rpm but the bad part is voltage continued to increase even after 4,000rpm. Usually voltage might increase from idle to 1,000rpm but that's about the end of the gains. This thing seemed like it was really loaded down.

After only 2 minutes of runtime I shut the engine off and discovered that the positive battery terminal was hot. The part going to the starter was ambient, the audio wire was ambient, but the short one going to the fuse box was hot. I felt each fuse and relay in the fuse box and could not find a warm spot other than the connection. Ill check the actual connection in the morning but its never been removed, I'm the original owner of the car. The wire to the starter was cool. The negative terminal on the battery was warm as well.

The alternator was extremely hot. This time it was the entire housing. The charging wire seemed to be warm but its hard to tell if it was conducting heat from the alternator or if it was carrying a lot of power.

I've noticed lately the car is harder than normal to start. I doubt I have another bad alternator so something is causing this. My question is are all diodes inside of the alternator or are there components somewhere else in the car. Ill check it for bad connections in the morning but assuming all connections are good; other than the ECU energizing and de-energizing the alternator, is everything else charging related inside the alternator.

I'm mostly asking if there is a known issue with these cars in this area or if I'm going to have to spend the morning troubleshooting. I know I don't have long to fix this before the alternator gets ruined again or the car catches on fire.

If I don't hear back from anyone ill update this with the fix in case anyone else has the issue. Maybe MrBell can merge this with the alternator thread. I wanted this topic to get responses or I would have just put it in the other thread.

Turbonut

iTrader: (1)

Alternators run hot, but will get extremely hot when asked for continued max output. I would say that depending on the alt pulley ratio, max output would be around 2500.
Make certain battery if fully charged and as you know, cables are clean and tight on the battery, then give it another try. You can also check the alt output at the 12v alt terminal to see if that is the same as the battery terminal.

I hate cars

I've been putting it off all morning, finally going to look at it. I hope you're right turbonut. The heat disappears at the fuse box, hopefully its just the battery to fusebox connection. I'm guessing this is what took out the original alternator over time.

erdoc48

I hate to ask the obvious (you guys know way more than me), but is it possible the battery itself is faulty? I just wonder as you indicated the alternator is hot (trying to power the car in the event the battery is poorly able to hold a charge, so more is demanded of it), and that the voltage of the battery was low with essentially very little demand on it. I've had issues with my bike in the past with a dying battery- I could get it to start, and it would seem to run OK, but once I took it on the road, the idle speed was low and then when the battery was nearing the end of its life, it would backfire and run like complete crap (as the alternator was powering the bike primarily). New battery installed = end of the problem. Plus, even if your battery isn't completely shot, they sometimes develop sulfation that results in internal shorts in the battery.

Just a thought...probably wrong though.

I hate cars

I've got 13.9v across the battery this morning so that's good but a .5v loss from the alternator to battery and .3v drop from the battery negative to the chassis negative.

Also, .3v drop from batt + to fuse box power.

Engine off= no drop across any of these. I guess the fusebox, alt connection, and ground checking time, my favorite things to do.

I hate cars

No, thank you. Everything is welcome. The battery was replaced about a year ago with a Diehard Platinum. The battery seems to be the center of all of the power drops, .01v drop from the alt to fusebox, but .5v from the batt to alt and .3v from batt to fusebox. I really hope this battery is compatible with this charging system, it would be the first I've ever heard of it not being compatible.

I'm probably going to do to this car what I did to my old car at about the same age, make plenty of redundant grounds and an extra power wire or two with correct fusing of course. I hate electrical problems.

hofiveo

http://www.madelectrical.com/electrical-tech.shtml
The above link might help troubleshoot or understand the system(mostly gm systems), that we may have forgotten. Im with you on this though, it sounds like a connection issue. Something inside alternator or battery or wire going somewhere. If I have this problem atleast we will know the problem and how to solve with you taking this on. Good excuse to purchase the Power Probe 3 test tool?

I hate cars

I love Mad enterprises. I used to buy connectors by the hundreds and probably 50' of heat shrink.

I think I've found the problem. I've got a consistent 13.8v across the battery. I replaced the nut on the alt power wire which was questionable when I installed it along with cleaning the connections. I did the battery terminals and cables and reduced voltage drop from the alt to battery to .3v from .5v but the main change is at the fuse box. One connector going to the battery was getting very hot very fast. That's with no load, just idling with no electrical components on. I had a .3v drop on this very short run and now its .1v which is still too high but better. I removed the connector and did the usual cleaning but a lot of the heat seemed to come from the crimp. I smashed down the crimp some more and that reduced the voltage drop. It's still getting warm but it takes longer and it doesn't get hot enough to burn my fingers anymore. I'm sure as it runs longer and gets hotter the voltage drop is going to get worse as well as the heat so ill probably jus order a whole positive battery terminal which I'm sure is not cheap. I don't like screwing with electrical problems.

Also alt voltage at the alt is lower and batt voltage is higher. Now when a fan kicks on the voltage at the battery doesn't go down and stay down, it dips for a second and comes right back up as it should.

It's not over yet but I think the worst is over.

Edit: the engine turns over far faster than it has since I first replaced the battery.

Jackass

The positive battery cable is about $45 I think. I had a thread about that last year when mine broke.

I hate cars

I've been driving around for a while now, making several short trips with the AC, stereo, and headlights going. It turns over on the starter quicker than ever. No more dimming of the inside lights everytime a fan kicks on. So far no more surging. The battery light on the dash came on a couple times randomly at first but for the last hour nothing.

As the battery charged up, the voltage drop between the battery to alternator went down to .1v and sometimes less, I guess that's the normal drop from charging the battery. Cleaning all connections up and changing to a better nut on the alternator power wire reduced voltage drop considerably but what seems to have fixed the problem was redoing the factory crimp on the batter wire from the fuse box, where it was getting really hot. I think this was causing the alternator to go to full output or near full output all the time. It might have explained the more labored idle the car has had for a while. Now, unless the AC compressor is engaged you can't tell if the engine is running while sitting at a redlight. Looking back I think this has been going on for a while and getting worse over time.

Jackass- It would be great if that cable is that cheap. It looks like all one piece, from the battery to alternator to starter, to fuse box but I might be wrong. Did yours have all of these connections included?

For what it's worth, all of these connections ohmed out perfectly, it wasn't until some decent current was passed through them that the problem showed up.

I guess it's something to look at if anyone else has this problem. I doubt it will help anyone, I can't imagine this crimp being a common defect but for what it's worth, it was the heat the led me to that connection.

This also goes to show why all of this stuff should be checked out when the alternator was replaced. If I hadn't gotten lazy when I did the alternator I would have caught this before I nearly destroyed another alternator.

Jackass

I took mine to the dealer so I never actually saw it. I looked up the part online which is how I knew the dealer markup was just stupid.

hofiveo

IHC will you elaborate more on the nut for the alternator being questionable? Ive replaced a bunch of alternators and can not think of any problems with the nut other than being small.

http://custombatterycables.com/index.htm This place has many options to replace our One piece positive battery cable. I purchased his custom battery cables for our 3 2000-2001 Ford F-350 Powerstrokes and they are very well made. When i have time i will be building my own for my 04 TL with some help from MAD Enterprises.

I hate cars

The nut was probably fine but since I was clueless a that point I replaced it anyway. It was one of those nuts with a "built in" washer. Not a part of the nut itself but pressed on where the nut can turn but the washer remain stationary. I could see the way the washer was contacting the power wire that only the washer was making contact which is perfectly fine but I thought what if somehow it was losing a little something between the washer and the nut. Not very likely I know, but I was desperate lol.

hofiveo

I understand now, i was racking my brain on how a nut would cause a problem. Desperate times, desperate measures.

Thomas Houck

I have a2007 Acura tl v7, I've replaced the alternator3 times ,I only gry12.7 volts at alt. And batt? Could be a fuse under hood ?