Can re-grounding lead to death of alternator? ('91 auto->manual coupe)
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Joined: Jun 2003
Posts: 72
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From: la, ca, usa
Can re-grounding lead to death of alternator? ('91 auto->manual coupe)
Hey all,
So I live in LA, but my '91 coupe has been stuck in Memphis for the last year and a half. Short backstory: It was an automatic, but I and a very awesome 7 mechanic did a tranny swap - unfortunately, after the swap the heating and a/c were getting no power, including the lights beneath the heat/a/c buttons on the console.
About nine months ago I came back into town, where my friend had been starting it up and driving it around every month, but the battery wasn't holding a charge so I replaced it, thinking at the time that I was going to drive back then. Well, I couldn't, so - again - it was started up and driven around once a month 'til now. When I got into town on the 19th, I immediately got the 7 and was driving it around, getting the tires rotated, etc. getting ready for the drive back. Then I decided driving back to LA in January would be much nicer if my heat worked.
Since I have no garage or mechanic friend here, I took it in to RX-7 Heaven, which you'd think would know something about 7s. (They had some really sweet 2nd and 3rd gens they'd modded themselves - it was enough to sell me over.) Anyway, they diagnosed faulty grounding, and when I got it back the heat and a/c and button lights worked fine.
However, same day, I notice all the dashboard lights lighting up when I'm in neutral, usually coasting to a light. They went on for a split second and then went back off. Later that night, with the lights on, all the dashboard lights came on for longer, and when they came on I noticed a drop in batt power from the usual 14 to 12 and slowly falling, and once it gets to 10 the lights start dimming. But then suddenly the dash lights go back off the batt power's up at 14 again. When the lights are on and the batt is at 12, revving the engine won't cause a rise in batt power - but once I parked I gave it a good rev, and suddenly the lights went off, the power was back up to 14, and I saw the engine light stay on a second longer than the other dash lights and then go out.
First thing in the morning I'm going to go get my battery checked, then take the 7 BACK to RX-7 Heaven and get them to test my alternator, connections, and grounding. (Voltometer's + terminal to the - batt post and - terminal to the alternator frame, max reading .3 volts, is the best way to make sure the alternator's properly grounded, right?) I know how to test for shorts using a test light, but not a voltometer - although I'm sure the mechanics there know far more about this, it'd be good for my peace of mind to make sure they're testing everything and not just throwing a new alternator in.
So. Is this just a really handy time for my alternator to decide to die? Or did this new re-grounding **** **** up? If this is the case, I'm reticent to buy a new alternator before the cause of the old one's untimely demise is found and solved. Any experience, comments, commisery would be appreciated.
(And I was planning to drive the 7 back to LA, TOMORROW - either the alt picked a really bad time or a really good time (i.e. before I got stranded in TX) to crap out.)
So I live in LA, but my '91 coupe has been stuck in Memphis for the last year and a half. Short backstory: It was an automatic, but I and a very awesome 7 mechanic did a tranny swap - unfortunately, after the swap the heating and a/c were getting no power, including the lights beneath the heat/a/c buttons on the console.
About nine months ago I came back into town, where my friend had been starting it up and driving it around every month, but the battery wasn't holding a charge so I replaced it, thinking at the time that I was going to drive back then. Well, I couldn't, so - again - it was started up and driven around once a month 'til now. When I got into town on the 19th, I immediately got the 7 and was driving it around, getting the tires rotated, etc. getting ready for the drive back. Then I decided driving back to LA in January would be much nicer if my heat worked.
Since I have no garage or mechanic friend here, I took it in to RX-7 Heaven, which you'd think would know something about 7s. (They had some really sweet 2nd and 3rd gens they'd modded themselves - it was enough to sell me over.) Anyway, they diagnosed faulty grounding, and when I got it back the heat and a/c and button lights worked fine.
However, same day, I notice all the dashboard lights lighting up when I'm in neutral, usually coasting to a light. They went on for a split second and then went back off. Later that night, with the lights on, all the dashboard lights came on for longer, and when they came on I noticed a drop in batt power from the usual 14 to 12 and slowly falling, and once it gets to 10 the lights start dimming. But then suddenly the dash lights go back off the batt power's up at 14 again. When the lights are on and the batt is at 12, revving the engine won't cause a rise in batt power - but once I parked I gave it a good rev, and suddenly the lights went off, the power was back up to 14, and I saw the engine light stay on a second longer than the other dash lights and then go out.
First thing in the morning I'm going to go get my battery checked, then take the 7 BACK to RX-7 Heaven and get them to test my alternator, connections, and grounding. (Voltometer's + terminal to the - batt post and - terminal to the alternator frame, max reading .3 volts, is the best way to make sure the alternator's properly grounded, right?) I know how to test for shorts using a test light, but not a voltometer - although I'm sure the mechanics there know far more about this, it'd be good for my peace of mind to make sure they're testing everything and not just throwing a new alternator in.
So. Is this just a really handy time for my alternator to decide to die? Or did this new re-grounding **** **** up? If this is the case, I'm reticent to buy a new alternator before the cause of the old one's untimely demise is found and solved. Any experience, comments, commisery would be appreciated.
(And I was planning to drive the 7 back to LA, TOMORROW - either the alt picked a really bad time or a really good time (i.e. before I got stranded in TX) to crap out.)
i have no clue how to help you but as a fellow auto 91 suffering owner... can i please get some pics of your tranny crossmember fabrication or what ever you used to mount the manual tranny? im stumped as to how to do it and if it'll be strong enough to take abuse. thanks man and sorry i cant help. i just dont know about that kind of stuff. at least you get a bump out of my question.
Thread Starter
Full Member
Joined: Jun 2003
Posts: 72
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From: la, ca, usa
And:
Forgot to add this to first post:
When my batt was the lowest, the radio shut off - or at least stopped playing - and then came back on full blast. Also, the dash lights came on regardless of whether I had my headlights on or off, the heather on or off, or the radio on or off (although having the radio on seemed to get those dash lights coming on pretty damn quick).
I'm resigned to the fact that my alternator is crapped, although I'll def be asking them to check the connections and grounding for a short (or I'll be checking my damn self - voltometers aren't too expensive in Memphis). But any suggestions as to what in the process of grounding the heater/ a/c could drain the alternator, or cause it to die? I mean, it happened as soon as the heater/ a/c was hooked up - I'm finding it hard to accept it as a coincidence, slap a new alternator on it, and then immediately drive across the country.
When my batt was the lowest, the radio shut off - or at least stopped playing - and then came back on full blast. Also, the dash lights came on regardless of whether I had my headlights on or off, the heather on or off, or the radio on or off (although having the radio on seemed to get those dash lights coming on pretty damn quick).
I'm resigned to the fact that my alternator is crapped, although I'll def be asking them to check the connections and grounding for a short (or I'll be checking my damn self - voltometers aren't too expensive in Memphis). But any suggestions as to what in the process of grounding the heater/ a/c could drain the alternator, or cause it to die? I mean, it happened as soon as the heater/ a/c was hooked up - I'm finding it hard to accept it as a coincidence, slap a new alternator on it, and then immediately drive across the country.
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