'91 525i +battery terminal melted through ??

[kalsman]

I went out to start my car this morning and nothing happened. No lights, no sounds, no power whatsoever. I checked under the hood to find that the battery terminal on the positive side had melted into two parts (the clamp around the post and the clamp around the wires). What should I make of this?

Also, if anybody can recommend a good shop in the Seattle area I would appreciate it.

[kalsman]

Well I just talked to a friend and he said the battery might be messed up and suggested I try a new one. If that doesn't work, he said to check out the alternator. I have no clue how to diagnose but can probably figure out how to fix things once I know what is wrong. Do these seem like logical steps to figure out what the problems is?

[dacoyote]

It sounds like you got something farked up....

I wouldn't trust the battery anymore, get the car going and see what the voltage is.. there is a way to unlock the obc to see what the voltage is.

[Bill R.]

cause of the problem quite possibly the battery terminal itself. It sounds like someone had put a replacement cable end on your battery cable from what your describing, if there's any corrosion or oxidation there(which there frequently is on these aftermarket cable clamp things) then you could have an area of very high resistance which heated up under load and melted .. Always make sure the battery terminals are clean and the cable ends are clean with no corrosion/oxidation/buildup first before condemning any other parts.





Well I just talked to a friend and he said the battery might be messed up and suggested I try a new one. If that doesn't work, he said to check out the alternator. I have no clue how to diagnose but can probably figure out how to fix things once I know what is wrong. Do these seem like logical steps to figure out what the problems is?

[dacoyote]

http://home.iae.nl/users/bts/obc.htm

[kalsman]

Thanks for the reply. I am almost positive this is the problem. Looking at the 3 cables that go to the + terminal I can see that all 3 are corroded and the main cable is bare (coating melted off) about 5 inches. Is this something I can take care of myself or should I take it to an auto electric shop to have all of the cables replaced?


cause of the problem quite possibly the battery terminal itself. It sounds like someone had put a replacement cable end on your battery cable from what your describing, if there's any corrosion or oxidation there(which there frequently is on these aftermarket cable clamp things) then you could have an area of very high resistance which heated up under load and melted .. Always make sure the battery terminals are clean and the cable ends are clean with no corrosion/oxidation/buildup first before condemning any other parts.

[kalsman]

I already unlocked my obc and checked the voltage just the other day to find that while running it was at roughly 13.4.


It sounds like you got something farked up....

I wouldn't trust the battery anymore, get the car going and see what the voltage is.. there is a way to unlock the obc to see what the voltage is.

[callen]

I'd seriously consider using an Ohm meter to see if the positive cable is grounded before putting a charged battery in there and have it happen again. I had BMW replace voltage regulator under warrantee and when they tightened the terminal to back of alternator it was too close and eventually grounded to the frame...causing similiar problem.

[kalsman]

What would the meter read for both instances?...and if it isn't grounded, what to do then?


I'd seriously consider using an Ohm meter to see if the positive cable is grounded before putting a charged battery in there and have it happen again. I had BMW replace voltage regulator under warrantee and when they tightened the terminal to back of alternator it was too close and eventually grounded to the frame...causing similiar problem.

[Bill R.]

Callen suggests ,you can always hook the positive up first like you should and then as soon as you start to hook the negative up you'll know instantly if there is a short and you quickly remove the cable..The arcing when you hook it up and the heat generated quickly will tell you. There is always a small spark when you connect the battery but if its a large arc it will be obvious.




Thanks for the reply. I am almost positive this is the problem. Looking at the 3 cables that go to the + terminal I can see that all 3 are corroded and the main cable is bare (coating melted off) about 5 inches. Is this something I can take care of myself or should I take it to an auto electric shop to have all of the cables replaced?

[kalsman]

Thanks for the replies everybody. I may be in over my head though. Seeing as I have neither an ohm meter or any idea what to do with the readings I may just have to take it somewhere...unless somebody would be willing to walk me through the steps ;)


Callen suggests ,you can always hook the positive up first like you should and then as soon as you start to hook the negative up you'll know instantly if there is a short and you quickly remove the cable..The arcing when you hook it up and the heat generated quickly will tell you. There is always a small spark when you connect the battery but if its a large arc it will be obvious.

[callen]

If it's grounded it will have no resistance.....put it on any scale in Ohm range...touch to a good ground then positive on cable and see if needle or digital readout go to Zero. If so don't connect battery. Have you done any work on your car recently? Again you may want to check the positive lug on Alt. to make sure it's not touching frame. Good luck.

[kalsman]

Thanks. I'll give it a shot tonight. This is actually the second time this problem has happened. About a week ago it did the same thing and all I did was replace the battery terminal and it worked fine until this morning.


If it's grounded it will have no resistance.....put it on any scale in Ohm range...touch to a good ground then positive on cable and see if needle or digital readout go to Zero. If so don't connect battery. Have you done any work on your car recently? Again you may want to check the positive lug on Alt. to make sure it's not touching frame. Good luck.

[Kalevera]

Thanks. I'll give it a shot tonight. This is actually the second time this problem has happened. About a week ago it did the same thing and all I did was replace the battery terminal and it worked fine until this morning.
?! Would've been good to know about that part of the history at the beginning of all of this, hmm?! :)

I agree with Callen, Bill. You've got high resistance, a bad ground, or something very similar. Once the original battery terminal is gone, there's not much to do beyond replacing it or the line itself. If you DIY the repair, pick up a tube of dielectric grease, which is always handy.


http://www.iaibmvsp.org (soon to be renamed) should list a competent shop in the seattle area.

best, whit

[kalsman]

well I just switched out the terminal and it works perfect now. Before I installed the new one I tried to start the car one more time and this go-around the cabin lights turned on and the engine started to turn over but never actually started. Just cranking and cranking till i stopped turning the key. Anyway, I'm back on the road for now...mainly till I can get it to a shop to get it fixed for real...unless you guys have any more ideas ???

Also, thanks for all the advice and help.


?! Would've been good to know about that part of the history at the beginning of all of this, hmm?! :)

I agree with Callen, Bill. You've got high resistance, a bad ground, or something very similar. Once the original battery terminal is gone, there's not much to do beyond replacing it or the line itself. If you DIY the repair, pick up a tube of dielectric grease, which is always handy.


http://www.iaibmvsp.org (soon to be renamed) should list a competent shop in the seattle area.

best, whit

[Bill R.]

the wire are cleaned up and all corrosion removed. Good contact is essential to keep it from happening again.




well I just switched out the terminal and it works perfect now. Before I installed the new one I tried to start the car one more time and this go-around the cabin lights turned on and the engine started to turn over but never actually started. Just cranking and cranking till i stopped turning the key. Anyway, I'm back on the road for now...mainly till I can get it to a shop to get it fixed for real...unless you guys have any more ideas ???

Also, thanks for all the advice and help.