battery connection screw up |
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battery connection screw up |
dt4 |
Jan 12 2020, 09:57 AM
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#1
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Senior Member Group: Members Posts: 503 Joined: 26-May 19 From: England Member No.: 23,161 Region Association: England |
I have had the battery off the car whilst stripping paint and priming etc.... but thought it would be good to turn the engine over and run it for a while to keep things in good health etc.....
I had the battery on the bench to charge it and then put it back in the car but very stupidly put the negative lead to positive terminal and positive lead to negative terminal. I didnt turn the key as I was checking other things when I realised what I had done. I noticed that there was a smell of smoke coming from the alternator area and the tin on top of the engine in that area was warm so suspect there is a connector to the alternator under there? I put the terminals on the right way around and tried to start the engine but it appeared the battery had drained? I recharged the battery overnight but wouldnt start, again the battery seemed low on charge Apart from seemingly screwing the battery, is there other damage likely to have occured cheers David |
Superhawk996 |
Jan 12 2020, 12:04 PM
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#2
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914 Guru Group: Members Posts: 6,598 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
(IMG:style_emoticons/default/sad.gif)
There is almost certainly other serious damage if you smelled smoke. There is no simple answer. If you're not experienced at electrical troubleshooting or lacking for patience I would recommend that it go to an electrical specialty shop. You don't mention if you have original fuel injection of if the vehicle has been switched to Carbs. At this point having Carbs would work in your favor since there is a possibility that the fuel injection ECU (amonst other things) just got fried. If you have a schematic, patience, and some experience with electrical items, you'll just have to start tracing wires, checking for blown fuses, looking for blown relays, searching for burned wires, etc. |
wndsrfr |
Jan 12 2020, 12:32 PM
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#3
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Senior Member Group: Members Posts: 1,441 Joined: 30-April 09 From: Rescue, Virginia Member No.: 10,318 Region Association: MidAtlantic Region |
I have had the battery off the car whilst stripping paint and priming etc.... but thought it would be good to turn the engine over and run it for a while to keep things in good health etc..... I had the battery on the bench to charge it and then put it back in the car but very stupidly put the negative lead to positive terminal and positive lead to negative terminal. I didnt turn the key as I was checking other things when I realised what I had done. I noticed that there was a smell of smoke coming from the alternator area and the tin on top of the engine in that area was warm so suspect there is a connector to the alternator under there? I put the terminals on the right way around and tried to start the engine but it appeared the battery had drained? I recharged the battery overnight but wouldnt start, again the battery seemed low on charge Apart from seemingly screwing the battery, is there other damage likely to have occured cheers David I've been there, done that. It kills diodes and possibly more in the alternator... likely have to replace it... easy to do on a T4, PITA on my /6.... |
dt4 |
Jan 12 2020, 12:42 PM
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#4
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Senior Member Group: Members Posts: 503 Joined: 26-May 19 From: England Member No.: 23,161 Region Association: England |
I'll start with a new battery and replacement alternator (when I find one) and take it from there
thanks for the replies |
Mark Henry |
Jan 12 2020, 01:50 PM
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#5
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that's what I do! Group: Members Posts: 20,065 Joined: 27-December 02 From: Port Hope, Ontario Member No.: 26 Region Association: Canada |
The radio is likely toast but most else on the dash end is OK I'd think.
I have OCD triple checking, then checking again when it comes to connecting batteries. Always the ground is the first off and last on connections. |
dt4 |
Jan 12 2020, 02:07 PM
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#6
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Senior Member Group: Members Posts: 503 Joined: 26-May 19 From: England Member No.: 23,161 Region Association: England |
Is it safe to put a new battery on the car and try it?
If the alternator is toast, what effect would trying to start it have? |
Superhawk996 |
Jan 12 2020, 02:32 PM
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#7
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914 Guru Group: Members Posts: 6,598 Joined: 25-August 18 From: Woods of N. Idaho Member No.: 22,428 Region Association: Galt's Gulch |
Is it safe to put a new battery on the car and try it? If the alternator is toast, what effect would trying to start it have? I would not start by installing a new battery and hoping for best given that you smelled smoke. You likely have shorted wiring now either from melting and possibly from diodes. When diodes fail they usually go open but I wouldn't risk it. At least start by using an Digtital Multi Meter to see if the battery + is shorted to ground. After that I wouldn't even consider attaching the battery until you've inspected all the engine harness wiring starting with the alternator and the ignition coil. |
SirAndy |
Jan 12 2020, 03:17 PM
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#8
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Resident German Group: Admin Posts: 41,943 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
I would not start by installing a new battery and hoping for best given that you smelled smoke. You likely have shorted wiring now either from melting and possibly from diodes. When diodes fail they usually go open but I wouldn't risk it. At least start by using an Digtital Multi Meter to see if the battery + is shorted to ground. After that I wouldn't even consider attaching the battery until you've inspected all the engine harness wiring starting with the alternator and the ignition coil. (IMG:style_emoticons/default/agree.gif) Don't put a battery back in there until you tested all wires ... (IMG:style_emoticons/default/popcorn[1].gif) |
SirAndy |
Jan 12 2020, 03:20 PM
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#9
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Resident German Group: Admin Posts: 41,943 Joined: 21-January 03 From: Oakland, Kalifornia Member No.: 179 Region Association: Northern California |
Don't put a battery back in there until you tested all wires ... (IMG:style_emoticons/default/popcorn[1].gif) You don't want to run current through something like this: (IMG:http://www.914world.com/bbs2/uploads/post-179-1202691212_thumb.jpg) (IMG:http://www.914world.com/bbs2/uploads/post-179-1202691244_thumb.jpg) (IMG:http://www.914world.com/bbs2/uploads/post-179-1202691265_thumb.jpg) |
dt4 |
Jan 13 2020, 01:25 AM
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#10
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Senior Member Group: Members Posts: 503 Joined: 26-May 19 From: England Member No.: 23,161 Region Association: England |
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Breaker |
Jan 13 2020, 03:57 AM
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#11
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Newbie Group: Members Posts: 8 Joined: 11-September 12 From: Switzerland Member No.: 14,911 Region Association: None |
Just one additional thought:
IF the alternator is new, and IF has never been used since it was installed, then it could be an issue with the + threaded stud touching the alternator tin. It's often too long, and this would short regardless of polarity. |
Chi-town |
Jan 13 2020, 10:41 AM
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#12
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Senior Member Group: Members Posts: 851 Joined: 31-August 18 From: Disneyland Member No.: 22,446 Region Association: Southern California |
Do not install the new battery. Pull the alternator and check for damaged insulation on the primary wire.
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914fahrer |
Jan 13 2020, 11:32 AM
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#13
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Member Group: Members Posts: 103 Joined: 12-November 14 From: Berlin/Germany Member No.: 18,115 Region Association: Germany |
I think You shot the diodes of the altenator.They resist this only a short time. (IMG:style_emoticons/default/sad.gif)
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dt4 |
Jan 13 2020, 02:48 PM
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#14
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Senior Member Group: Members Posts: 503 Joined: 26-May 19 From: England Member No.: 23,161 Region Association: England |
Do not install the new battery. Pull the alternator and check for damaged insulation on the primary wire. will do Dylan, things were going so well !! (IMG:style_emoticons/default/thumb3d.gif) |
dt4 |
Jan 13 2020, 02:49 PM
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#15
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Senior Member Group: Members Posts: 503 Joined: 26-May 19 From: England Member No.: 23,161 Region Association: England |
I think You shot the diodes of the altenator.They resist this only a short time. (IMG:style_emoticons/default/sad.gif) I have found some one close by that repairs alternators so I will get it over to him |
Chi-town |
Jan 13 2020, 06:47 PM
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#16
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Senior Member Group: Members Posts: 851 Joined: 31-August 18 From: Disneyland Member No.: 22,446 Region Association: Southern California |
Ok, if you need an alternator or harness let me know and we'll get one shipped.
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KELTY360 |
Jan 13 2020, 08:13 PM
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#17
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914 Neferati Group: Members Posts: 5,096 Joined: 31-December 05 From: Pt. Townsend, WA Member No.: 5,344 Region Association: Pacific Northwest |
This is a great learning opportunity to get to know your multimeter. Spend time learning to test electrical functions. You’ll be better prepared the next time you let the smoke escape from the wires.
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DickSteinkamp |
Jan 13 2020, 10:13 PM
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#18
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Senior Member Group: Members Posts: 500 Joined: 27-February 17 From: Bellingham, WA Member No.: 20,876 Region Association: None |
Electricity is somewhat of a mystery to me so bear with me.
I don't understand how switching the + and - leads can cause a dead short and burn up wiring. I can understand how polarity sensitive devices (like a diode) might be harmed but why wiring? Also, there is so very little that gets power with the key in the off position. How would the radio (for example) be damaged? |
bbrock |
Jan 13 2020, 10:26 PM
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#19
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914 Guru Group: Members Posts: 5,269 Joined: 17-February 17 From: Montana Member No.: 20,845 Region Association: Rocky Mountains |
Electricity is somewhat of a mystery to me so bear with me. I don't understand how switching the + and - leads can cause a dead short and burn up wiring. I can understand how polarity sensitive devices (like a diode) might be harmed but why wiring? Also, there is so very little that gets power with the key in the off position. How would the radio (for example) be damaged? The way I see it, any circuit that is switched and the switch was off when the battery was connected backward should be fine. Any circuit that is always energized is subject to damage. Modern radios often have a switched and unswitched circuit and of course, any radio can be wired either switched or not. |
dt4 |
Jan 14 2020, 02:54 AM
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#20
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Senior Member Group: Members Posts: 503 Joined: 26-May 19 From: England Member No.: 23,161 Region Association: England |
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