Yesterday the battery light on my 89 RT4WD wagon (manual trans, 128K miles) lit up. A garage checked the battery with a meter and said its not getting any charge and I had a bad alternator. Is this likely correct, or should I check other things first? The bad news is he said to replace the alternator, he has to pull the left transaxle shaft and get it out through the bottom. And wants $140 labor to do it. I don't mind paying if there's a lot of work involved, but this surprised me. Is he on the level? Does anyone know for sure if the alternator can be R&Red from the top side? I used to do these routinely on other cars without any drama.
Installing Alternator Question
- Thread starter Cogito
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Dont know about your car, but my alternator went bad last week. i have a 94 honda accord, didnt bother taking it to a mechanic. The backside of the alternator could be unscrewed, and I took out the voltage regulator, and brushes, and replaced them with new ones, $45 in parts. I measured the battery, it's exactly at 14.5 volts, when revved and idle. Before (when the alt light was on) it was at 12volts.
Im sure if I went to a mechanic, they'd replace the whole thing, and charge me to take it off. So see if you can open it up first and replace the parts yourself, it was very easy. Took me 45 minutes including trip to the store.
Im sure if I went to a mechanic, they'd replace the whole thing, and charge me to take it off. So see if you can open it up first and replace the parts yourself, it was very easy. Took me 45 minutes including trip to the store.
what is an RT4WD? Toyota? Subaru? Nissan? Volkswagen?
Is the alternator on the bottom left side? Why not just remove the left front plastic inner fender liner and pull it out through the wheel well? That's how I changed out my A/C compressor - I pulled it out through the right front wheel well.
There's two possibilities here :
1) The battery is bad. It's bad because it's failed on it's own but the alternator is still fine, in which case you need a new battery but NOT a new alternator. If he just checked the battery terminal voltage but didn't check the alternator output with the engine running, you can't trust his diagnosis.
2) The battery is bad because the alternator failed, in which case you need a new alternator and *maybe* a new battery too, but maybe it will be fine once a new alternator is installed.
$140 labor is quite possible depending on how tough it is to get at the alternator. On my Intrepid, it was 2.5 hours labor @ $89/hr to change it because it's in a horrible place. Labor including tax was around $250 in my case. And this is one job where I was happy to pay someone else to do it. It would have taken me 6 hours to replace it without a hoist available, and it was the middle of winter when it happened.
1) The battery is bad. It's bad because it's failed on it's own but the alternator is still fine, in which case you need a new battery but NOT a new alternator. If he just checked the battery terminal voltage but didn't check the alternator output with the engine running, you can't trust his diagnosis.
2) The battery is bad because the alternator failed, in which case you need a new alternator and *maybe* a new battery too, but maybe it will be fine once a new alternator is installed.
$140 labor is quite possible depending on how tough it is to get at the alternator. On my Intrepid, it was 2.5 hours labor @ $89/hr to change it because it's in a horrible place. Labor including tax was around $250 in my case. And this is one job where I was happy to pay someone else to do it. It would have taken me 6 hours to replace it without a hoist available, and it was the middle of winter when it happened.
There is a tool that is better than a meter to check the charging system. Sun (now a division of Snap-on) makes one called a VAT -- Volt Amp Tester. There are similar tools marketed by other companies. It will check the battery and the alternator and starter (although you likely don't need the starter checked for this condition). This is the tool your mechanic (now days called a technician. That allows them to justify charging you more.
) should use to determine if the issue is the battery or the alternator. Using just a meter can yield a deceptive diagnosis. The charge for the use of this tool should be $25 or less, and may be free if you chose to have the work done at the shop that troubleshoots the problem. Of course, don't kid yourself you're paying for the test one way or another.
We used to have an expression where I worked (for a public utility): "Test, don't just replace." That works for cars too.
Sorry, but I have no experience with your model car so I can’t comment about the cost to R&R the alternator.
We used to have an expression where I worked (for a public utility): "Test, don't just replace." That works for cars too.
Sorry, but I have no experience with your model car so I can’t comment about the cost to R&R the alternator.
Autozone stores have that type of tool. They'll check the charging system for free with it. The one I saw them use wants you to run the engine at 2000RPM while it loads the electrical system down, then it tells you if the system passed and what the peak amperage draw was.
Yes, they have a tester they can bring out right to the car. It can test the battery, the alternator, and the starter.
Probably best to go when they're not very busy, like in the evening.
Probably best to go when they're not very busy, like in the evening.
Do you have a digital multimeter? Put it across the battery with the car off. Have someone start the car, watch the voltage drop. If it doesn't drop below 11 or so, the battery is probably fine. Now, with the car running, check the voltage. It should be 14.0 or 14.2 if the alternator is putting out. If it isn't, it will be lower or discharging.
I've seen voltages as low as 13.4V with the engine running, in a properly functioning system.
Basically you will only see the higher voltages when the alternator is cold, and it cuts back on the voltage as it warms up.
I've seen as high as 14.8V in the winter.
Basically you will only see the higher voltages when the alternator is cold, and it cuts back on the voltage as it warms up.
I've seen as high as 14.8V in the winter.
VAT Machines(Made by SUN) are great. However, they are big and bulky. And the technician needs to know how to correctly use it. Now they have electronic charging and starting system testers, which are much smaller, and idiot proof. But that's secondary.
All you need to test an alternator is a voltage meter. If its charging anything less than about 13.8 V at the battery, the alternator is bad. Simple as that.
All you need to test an alternator is a voltage meter. If its charging anything less than about 13.8 V at the battery, the alternator is bad. Simple as that.
Do you mean that you test the voltage of the wire coming from the alternator to the battery?
I believe its as stated above, just run the leads across the battery while the car is running.
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