http://www.2carpros.com/topics/alternat.htm
Question: 1987 Honda Accord LX with 170,000 (4 cyl). We purchased a used Honda about a year ago for my daughter. One meticulous previous owner with a little black book with all records kept it in great condition. About 2 months ago, the battery light went on and then her car went dead. We jumped it a few times and got it in for a check. It was the alternator. I had it replaced. Less than a month later, the battery light went on, and it was the alternator again. The parts distributor replaced and even reimbursed 1/2 of the mechanic's fee. They checked the battery, and it was fine when I had the service done and the new alternator put in. Again today, the light went on. It has only been two weeks! What in the world is happening? I am afraid to let her drive it. Other than that, the only thing I have had replaced was the ignition switch in January. I am embarrassed to go back to the parts distributor...they really have been great, but in the meantime I'm wasting a ton of money on mechanic's fees.
Answer: We suspect that you are getting faulty alternators in view of the fact that you have had to replace two of them in the last month. Load test the battery and then check the electrical system for drains and also for poor ground connections.
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Question: 1993 Pontiac Grand Am Quad 4. How do you remove the alternator? We've removed two bolts & the serpentine belt, but it remains un-budge able. Clearly there's another bolt - but where? We've searched high and low, including useless groping by hand, to no avail. The repair manual we bought simply says "remove retainer bolts" which is like saying: to get to New York, get in car and drive. Help! Otherwise, we'll have to use the A-10 Warthog and just blast away....
Answer: Without seeing your car, it is difficult to advise you. We would look at the replacement alternator to see where the boltholes are to give you an idea on where to look on the one you are removing.
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Question: 1984 Mercury Grand Marquis 5.0 mileage: 150,000. Refresh my memory a bit; forgot how to check if my alternator itself is ok. Alternator currently in vehicle was rebuilt and boosted to 100 amps instead of the normal 65-70-amp type. Your response would be greatly appreciated. Thank you.
Answer: Assuming the battery in your car is in good condition, you can check the alternator by having the engine on a fast idle with the headlights and the air-conditioner on. The voltage across the battery should be 14 to 14 ½ volts. Double check to see that the alternator belt is tensioned properly and in good condition.
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Question: 1987 Dodge 250 Ram Van 318 cu in mileage: 80,000. The alternator was not charging - had new brushes put in. Since then, once in awhile the alternator will go to full charge and the lights will get over bright. Some say it is the voltage regulator but we cannot find it. It is not in the alternator and it is not on the firewall some say it's built into the computer. It only does it once in awhile but I'm afraid it is going to burn out my headlights when it does it. Thank for your help.
Answer: Assuming the alternator is all right, your problem may be the voltage regulator. Unfortunately, it is located in the computer and the only remedy is to replace the computer. If money is an issue, we have seen external regulators installed, however, we do not recommend this.
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Question: 1988 Ford Ranger 2.9L mileage: 129,000. A few weeks ago, my charge light started coming on intermittently, and my battery has since died. The alternator is putting out (the exact amps I do not know). I found this out using some shade tree methods (removing cables while engine is running, feeling magnetic pull on back of alternator). I have since replaced the battery, and the charge light still comes on, however it stops glowing at idle with the headlamps on. It will appear again upon acceleration. Any ideas?
Answer: From what you tell us, it sounds like you may be having trouble with your charging system. Have your battery load tested and check the alternator output for voltage and amperage. It is not a good idea to remove the battery cables when the engine is running.
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Question: 1997 Ford / F150 4.6l v8 mileage: 105,000. I have a problem. I think it is my alternator, but I am a little unsure. Periodically, my lights dim and everything electrical will slow (ac, heater, etc.). After a short period, they will return to normal. At first I thought it might be a short, but it does not occur when I hit a bump nor does it go away on bumpy roads (once it stopped while sitting still). The last time it happened, my truck stalled when I stopped. It wouldn't restart. Then, about an hour later, it started as if nothing was wrong. Any ideas? I'm lost.
Answer: Here are some things to check. Load test the battery. Check that the battery cable connections are clean. Check for 12 volts to starter solenoid with the key in the start position. These things should be checked first then the ignition switch, starter and starter solenoid. One of these may be faulty.
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Question: 1986 Ford Aerostar 2.8L mileage: 135000. My 86 Aerostar runs on just battery power. I have changed the alternator and checked all of the wires. It will run for about 5 miles on a fully charged battery before the battery is completely drained. Do you have any suggestions?
Answer: Your definitely having some problems with the charging circuit. Check the alternator output for voltage and amperage. Also, check the main power wire from the alternator to the battery. Check your electrical system for electrical drains.
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Question: 1970 Ford/Econoline van 360 (?) mileage: 70,000. Just recently, I rebuilt my alternator, tried new batteries, checked my regulator, and replaced an old solenoid. The trouble is that when driven using accessories the battery looses power and will not run the engine. If the positive cable is removed while the engine is running, the engine will die. I am led to believe that somewhere in the wiring there is a short or a misplaced wire. If you can either give me advice or help me in any way, I would be very grateful.
Answer: Check alternator output for voltage and amperage. Check the main power wires from the alternator to the battery.
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Question: 1981 Buick Skylark v-6 mileage: ? My lights go dim then bright as I idle or drive. They stay either on for a couple minutes then change. I do not think it is the alternator because it does not brighten with acceleration. Please help me.
Answer: Have the battery load tested. Check the battery cables for good connections. Test the alternator output for voltage and amperage.
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Question: 1988 Ford Escort cyl. TBL mileage: 120000. The battery light suddenly came on and a DVM reading on the battery showed 13.5V not running and slowly drops to 12.3V when the engine is running. I believe the alternator is not charging. However, before I buy a rebuilt alternator could it be something else?
Answer: Before you buy another alternator, check present alternator for voltage and amperage output. In addition, load test the battery.
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Question: 1994 Geo Metro 3 cyl 108000. How do I replace my alternator?
Answer: First, disconnect the battery. Next, remove wiring from the alternator. Remove the drive belt and top and bottom bolts. Reverse the order to reinstall.
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Question: 1992 Chevrolet Camaro 350 V8 5.7lt mileage: 154,000. What could be the reason(s) that my alternator keeps going bad? I have had 3 put on since I bought the car in 1995. And I don't know if this is related to the above problem, but I cannot leave my car sit for a couple of days without being started and driven, or the battery goes dead. I have bought 3 batteries in the past 4 years also. Sometimes when the stereo's off, I can hear static and engine through my speakers. In case it is of importance, my stereo was installed in 1995.
Answer: The alternators you have been using may be of poor quality. If the diodes "bleed" a little A.C. voltage, it will shorten the life of the battery. Hearing static and engine noise on your speakers with the stereo off may indicate a wiring problem with the stereo installation. It also could cause your battery drain when the car is not driven for several days.
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Question: 1986 Lincoln Towncar_mileage: 112,000. The alternator went out and I replaced that. After I put the new alternator in, the car won't start. It turns over but it's not getting any spark. I replaced the coil and checked all the fusible links. The car will start if I run a wire from the positive side of the battery to the positive side of the coil. Can you give me any advise to go from there I'd greatly appreciate it.
Answer: Sounds like an ignition switch has failed.
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Question: 1990 dodge spirit 2.5 l mileage: 70000. Hi, my alternator over charges- periodically it puts out about 18 V and I can hear the battery sizzling. 1. I have swapped out the alternator- makes no difference (so the alternator is not the problem). 2. I have swapped out the battery- makes no difference. 3. Last Dec. I replace the computer so I would like to think this is not the problem. 4. I have checked the wiring harness. Any ideas?
Answer: Your problem may be simple like a loose or poor ground wire. On the other hand, maybe not. The voltage regulator is part of the computer. We have on occasion installed an external voltage regulator, not using the computer to control the voltage from the alternator.
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Question: 1974 mg midget, 1275. I recently bought a 1974 midget. I immediately replaced the gearbox. In the process, I replaced the GM alternator with the original Lucas. I also replaced the battery. For some reason, the alternator is not charging the battery and appears to be running on battery alone. It dies during operation and would not start until jumped. Other than it is a midget, do you have any ideas what could be wrong? I have the schematic, but wire colors appear to have been changed. There are three wires exiting the alternator. I assume something is broken or not there. I do not think it worked properly when I purchased it.
Answer: The original Lucas alternator requires an external voltage regulator. Two of the three wires you mentioned should hook-up to the regulator. Have the Lucas alternator "bench" tested for proper output. You may have to just trace wires one by one if the color-coding does not match.
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Question: 1993 Ford F-150 4.9l 6 cyl, mileage: 66,000. I am on my third battery in this truck. The voltmeter seems to set at a different voltage from one start up to another. Sometimes around 11 volts, sometimes up around 14. It doesn't always fluctuate with engine speed, but sometimes it will drop when at idle. I'm wondering if I have an alternator problem or a voltage regulator problem?
Answer: You are right the voltage regulator/alternator may be failing. But first check the drive belt for the alternator. Is it glazed and slipping? Is it tightened properly? Also, check the ground wires. Are they making a good Connection?
Question: 1987 Honda Accord LX with 170,000 (4 cyl). We purchased a used Honda about a year ago for my daughter. One meticulous previous owner with a little black book with all records kept it in great condition. About 2 months ago, the battery light went on and then her car went dead. We jumped it a few times and got it in for a check. It was the alternator. I had it replaced. Less than a month later, the battery light went on, and it was the alternator again. The parts distributor replaced and even reimbursed 1/2 of the mechanic's fee. They checked the battery, and it was fine when I had the service done and the new alternator put in. Again today, the light went on. It has only been two weeks! What in the world is happening? I am afraid to let her drive it. Other than that, the only thing I have had replaced was the ignition switch in January. I am embarrassed to go back to the parts distributor...they really have been great, but in the meantime I'm wasting a ton of money on mechanic's fees.
Answer: We suspect that you are getting faulty alternators in view of the fact that you have had to replace two of them in the last month. Load test the battery and then check the electrical system for drains and also for poor ground connections.
- - - - -
Question: 1993 Pontiac Grand Am Quad 4. How do you remove the alternator? We've removed two bolts & the serpentine belt, but it remains un-budge able. Clearly there's another bolt - but where? We've searched high and low, including useless groping by hand, to no avail. The repair manual we bought simply says "remove retainer bolts" which is like saying: to get to New York, get in car and drive. Help! Otherwise, we'll have to use the A-10 Warthog and just blast away....
Answer: Without seeing your car, it is difficult to advise you. We would look at the replacement alternator to see where the boltholes are to give you an idea on where to look on the one you are removing.
- - - - -
Question: 1984 Mercury Grand Marquis 5.0 mileage: 150,000. Refresh my memory a bit; forgot how to check if my alternator itself is ok. Alternator currently in vehicle was rebuilt and boosted to 100 amps instead of the normal 65-70-amp type. Your response would be greatly appreciated. Thank you.
Answer: Assuming the battery in your car is in good condition, you can check the alternator by having the engine on a fast idle with the headlights and the air-conditioner on. The voltage across the battery should be 14 to 14 ½ volts. Double check to see that the alternator belt is tensioned properly and in good condition.
- - - - -
Question: 1987 Dodge 250 Ram Van 318 cu in mileage: 80,000. The alternator was not charging - had new brushes put in. Since then, once in awhile the alternator will go to full charge and the lights will get over bright. Some say it is the voltage regulator but we cannot find it. It is not in the alternator and it is not on the firewall some say it's built into the computer. It only does it once in awhile but I'm afraid it is going to burn out my headlights when it does it. Thank for your help.
Answer: Assuming the alternator is all right, your problem may be the voltage regulator. Unfortunately, it is located in the computer and the only remedy is to replace the computer. If money is an issue, we have seen external regulators installed, however, we do not recommend this.
- - - - -
Question: 1988 Ford Ranger 2.9L mileage: 129,000. A few weeks ago, my charge light started coming on intermittently, and my battery has since died. The alternator is putting out (the exact amps I do not know). I found this out using some shade tree methods (removing cables while engine is running, feeling magnetic pull on back of alternator). I have since replaced the battery, and the charge light still comes on, however it stops glowing at idle with the headlamps on. It will appear again upon acceleration. Any ideas?
Answer: From what you tell us, it sounds like you may be having trouble with your charging system. Have your battery load tested and check the alternator output for voltage and amperage. It is not a good idea to remove the battery cables when the engine is running.
- - - - -
Question: 1997 Ford / F150 4.6l v8 mileage: 105,000. I have a problem. I think it is my alternator, but I am a little unsure. Periodically, my lights dim and everything electrical will slow (ac, heater, etc.). After a short period, they will return to normal. At first I thought it might be a short, but it does not occur when I hit a bump nor does it go away on bumpy roads (once it stopped while sitting still). The last time it happened, my truck stalled when I stopped. It wouldn't restart. Then, about an hour later, it started as if nothing was wrong. Any ideas? I'm lost.
Answer: Here are some things to check. Load test the battery. Check that the battery cable connections are clean. Check for 12 volts to starter solenoid with the key in the start position. These things should be checked first then the ignition switch, starter and starter solenoid. One of these may be faulty.
- - - - -
Question: 1986 Ford Aerostar 2.8L mileage: 135000. My 86 Aerostar runs on just battery power. I have changed the alternator and checked all of the wires. It will run for about 5 miles on a fully charged battery before the battery is completely drained. Do you have any suggestions?
Answer: Your definitely having some problems with the charging circuit. Check the alternator output for voltage and amperage. Also, check the main power wire from the alternator to the battery. Check your electrical system for electrical drains.
- - - - -
Question: 1970 Ford/Econoline van 360 (?) mileage: 70,000. Just recently, I rebuilt my alternator, tried new batteries, checked my regulator, and replaced an old solenoid. The trouble is that when driven using accessories the battery looses power and will not run the engine. If the positive cable is removed while the engine is running, the engine will die. I am led to believe that somewhere in the wiring there is a short or a misplaced wire. If you can either give me advice or help me in any way, I would be very grateful.
Answer: Check alternator output for voltage and amperage. Check the main power wires from the alternator to the battery.
- - - - -
Question: 1981 Buick Skylark v-6 mileage: ? My lights go dim then bright as I idle or drive. They stay either on for a couple minutes then change. I do not think it is the alternator because it does not brighten with acceleration. Please help me.
Answer: Have the battery load tested. Check the battery cables for good connections. Test the alternator output for voltage and amperage.
- - - - -
Question: 1988 Ford Escort cyl. TBL mileage: 120000. The battery light suddenly came on and a DVM reading on the battery showed 13.5V not running and slowly drops to 12.3V when the engine is running. I believe the alternator is not charging. However, before I buy a rebuilt alternator could it be something else?
Answer: Before you buy another alternator, check present alternator for voltage and amperage output. In addition, load test the battery.
- - - - -
Question: 1994 Geo Metro 3 cyl 108000. How do I replace my alternator?
Answer: First, disconnect the battery. Next, remove wiring from the alternator. Remove the drive belt and top and bottom bolts. Reverse the order to reinstall.
- - - - -
Question: 1992 Chevrolet Camaro 350 V8 5.7lt mileage: 154,000. What could be the reason(s) that my alternator keeps going bad? I have had 3 put on since I bought the car in 1995. And I don't know if this is related to the above problem, but I cannot leave my car sit for a couple of days without being started and driven, or the battery goes dead. I have bought 3 batteries in the past 4 years also. Sometimes when the stereo's off, I can hear static and engine through my speakers. In case it is of importance, my stereo was installed in 1995.
Answer: The alternators you have been using may be of poor quality. If the diodes "bleed" a little A.C. voltage, it will shorten the life of the battery. Hearing static and engine noise on your speakers with the stereo off may indicate a wiring problem with the stereo installation. It also could cause your battery drain when the car is not driven for several days.
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Question: 1986 Lincoln Towncar_mileage: 112,000. The alternator went out and I replaced that. After I put the new alternator in, the car won't start. It turns over but it's not getting any spark. I replaced the coil and checked all the fusible links. The car will start if I run a wire from the positive side of the battery to the positive side of the coil. Can you give me any advise to go from there I'd greatly appreciate it.
Answer: Sounds like an ignition switch has failed.
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Question: 1990 dodge spirit 2.5 l mileage: 70000. Hi, my alternator over charges- periodically it puts out about 18 V and I can hear the battery sizzling. 1. I have swapped out the alternator- makes no difference (so the alternator is not the problem). 2. I have swapped out the battery- makes no difference. 3. Last Dec. I replace the computer so I would like to think this is not the problem. 4. I have checked the wiring harness. Any ideas?
Answer: Your problem may be simple like a loose or poor ground wire. On the other hand, maybe not. The voltage regulator is part of the computer. We have on occasion installed an external voltage regulator, not using the computer to control the voltage from the alternator.
- - - - -
Question: 1974 mg midget, 1275. I recently bought a 1974 midget. I immediately replaced the gearbox. In the process, I replaced the GM alternator with the original Lucas. I also replaced the battery. For some reason, the alternator is not charging the battery and appears to be running on battery alone. It dies during operation and would not start until jumped. Other than it is a midget, do you have any ideas what could be wrong? I have the schematic, but wire colors appear to have been changed. There are three wires exiting the alternator. I assume something is broken or not there. I do not think it worked properly when I purchased it.
Answer: The original Lucas alternator requires an external voltage regulator. Two of the three wires you mentioned should hook-up to the regulator. Have the Lucas alternator "bench" tested for proper output. You may have to just trace wires one by one if the color-coding does not match.
- - - - -
Question: 1993 Ford F-150 4.9l 6 cyl, mileage: 66,000. I am on my third battery in this truck. The voltmeter seems to set at a different voltage from one start up to another. Sometimes around 11 volts, sometimes up around 14. It doesn't always fluctuate with engine speed, but sometimes it will drop when at idle. I'm wondering if I have an alternator problem or a voltage regulator problem?
Answer: You are right the voltage regulator/alternator may be failing. But first check the drive belt for the alternator. Is it glazed and slipping? Is it tightened properly? Also, check the ground wires. Are they making a good Connection?
