new battery installed backwards...car won't start!

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  #1  
Old 08-27-04, 07:47 PM
whlin76
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new battery installed backwards...car won't start!

My little brother has a 1990 Honda Civic DX HB with 5sp. He recently "tried" to install a new battery. But he wasn't paying attention and put the cables on backwards(+ with - and - with +). He told me there was a spark and that's when he realized he did something wrong.

One of the fuse under the dash was blown so we replaced it. All other fuses including the ones under the hood are okay. When we try to start the car, the engine turns but it won't start. All other electrical stuff like heater, lights, instrument panel, etc. seem to work but the engine just won't start. He took it to a local shop(who charged my naive brother over $100 for diagnosis) concluded that the ECU, Distributor and the Ignition Switch need to be replaced. I'm no mechanic but the fact that when we turn the key, the engines turns would indicate that the Ignition Switch is working. And I don't know why it would damaged the distributor in the first place. The damaged to ECU seems reasonable then again when I called the local Honda Dealer and spoke with one of their Techs, I got mixed opinions. One tech told me that there's no way any of the above mention components would be damaged from installing the cables backwards. It would have simply blown the fuses that are designed for such purpose. The other said it is possible that it might have damaged all of these under extreme case but wouldn't know for sure until they had the chance to take it apart($$$$).

At this point, I'm just trying to determine if it is worth repairing it. I realized that this was a rather dumb mistake but I've also heard it happens more often than not where people jump start their car backwards. With this in mind, I would think the engineers should have designed their cars little better to protect it.

I would greatly appreciate any insights or advises.

Thanks.
 
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  #2  
Old 08-27-04, 08:24 PM
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I would suggest getting another opinion at a reputable shop as something likely got damaged but it is unlikely that all those components would have been damaged.
computer or ignition igniter/module may have been damaged.
by getting another opinion and finding exactly whats wrong and what it will cost to fix will help you determine if its worth fixing or not.
 
  #3  
Old 08-27-04, 10:30 PM
whlin76
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Yes, that's a logical suggestion accept the car doesn't run. Which means I would have to pay to get it towed to a reputable shop then pay for another diagnostic fee.

My goal is to stop the "financial bleeding." That's why I'm posting my problem on this forum hoping for some sound repair advise from all you mechanical wiz out there. There's got to be some way of determining what the problem might be and the way to fix it.
 
  #4  
Old 08-27-04, 11:38 PM
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well you could check for fire at the plugs, check for injector pulse using a noid light and such so we know what the car has lost and you could check for power with a test light or voltmeter at ignition components such as coil, module, etc but even that may not be sufficient to diagnoss some computer problems or electrical parts in the distributer where a lab scope is generally used to check for incoming and outgoing signals from computer and distributer.
also you might note if your check engine or pgm fi light comes on when you turn the key on and goes out within a few seconds or not.
 
  #5  
Old 08-28-04, 04:24 AM
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Unfortunately, your problems are not of the simple variety normally addressed here in the forums that frequently have easily investigated causes. Not all problems can be solved on a Q&A bulletin board; sometimes the best answer IS that you may need to take it to a reputable shop for further diagnosis (even it that includes a tow bill). It's a gamble, but you wouldn't want to condemn the car for the cost of a $50 tow bill and a $100 diagnostic and then see it being driven around town by one of the guys from the junkyard. Only you can asnwer the question as to whether the car is worth the extra money. If it has 200,000 miles on it and the clutch slips a little and the engine has a bit of a knock - probably a no-brainer.

Is there a Vo-Tech in your area? Just a thought; they might be willing to fiddle with it for minimal cost.
 
  #6  
Old 08-28-04, 07:57 AM
MidlandZR1
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Welcome to the World of Electrical Gremlins. AS Tow Guy mentioned there is little that we can tell you through the computer. You basically pumped electrical currrent backwards through your whole car and most devices like lights do not care. Diodes in your alternator do care.

Fuses are to protect the rest of the car from one devise that shorts out and to prevent fires. If you radio shorts out (positive hooked directly to negative) than all you current would flow through it, killing your battery and alternator, and heating your wires to the point wher they would melt and start a fire. Fuses limit the amount of current permitted to flow into a device. When they pop the current stops flowing thus saving your battery and car.

Current can flow either way through a fuse so it makes sense few would pop. An ECm is a likely failure but as someone suggested, look for spark first. It could be your fuel pump burned out although its unlikely to happen in a split second. Pumps do not like to go backwards.

If you have fuel pressure ( fuel squires out of tube when engine cranks - caution a dangerous test ! ) and you have spark , than you are best to find a decent shop nearby.

What fuse popped? That should give you a clue as to where the current went. It will always flow the path of least resistance.
 
  #7  
Old 08-28-04, 08:12 AM
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Does the check engine lite prove out when you turn the key?

Have seen ECM's ruined by reverse polarity.
 
  #8  
Old 08-28-04, 09:17 AM
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I'm not 100% sure but I think Hondas have a main relay that can cause no start conditions.I would also remove every fuse and test them not just look at them to make sure they are bad.You may also have fusible links on the car that are not in the fuse block itself.
 
  #9  
Old 08-29-04, 08:22 PM
whlin76
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Davo: Funny you mentioned this because one of the Techs did tell me this could be one possible problem. How would I check to see if the Main Replay is bad? And where would it be located on 1990 Civic?

toyotaman11769: Yes the "Check Engine" light does come on along with all other lights when the key is "On" position.

MidlandZR1: My brother doesn't remember which fuse poped. The guy at Schuck's just replaced for him. Funny if he simply installed the battery for his customer to begin with, we won't be in this mess!

Thanks guys for all the sound advise.

Getting a 2nd opinion from more reputable shop will be ideal. Before that, I would like to try replacing the ECU and see if this would work. Here is what I think so please tell me if my theory makes sense:

ECU controls the both fuel systems and disbributor, right? So, if the ECU is dead, even if the engine turns, there'll be no command signal going thru. Therefore, there won't be any fuel being pumped nor any sparks on the plugs. Since I can not test the ECU without pluging it into another identical car, I have no way of knowing if it's sending any binary signals. I can check for the current flow but this would be pointless. I think I can get a used ECU from eBay for less than $50 so it's certainly cheaper than getting it towed and diagnosed assuming this is the sole problem. If not, the next logical place would be the Distributor... or is it?

Would this be an obvious waste of money or is there a good chance that this would work? Out of all the things that could be wrong with the car, would you guys agree that ECU and Distributor are the most likely source of the problem?
 
  #10  
Old 08-29-04, 11:28 PM
Chump2
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Chump2

Chances are good that the vehicle was having a hard time starting before the battery was replaced. By crossing the battery terminals, it is highly likely that damage would be done to the solenoid on the starter or to the starter motor its self. Easy to check with two people, one turning the key, the other listening to anything going on at the starter.

If it is turning over and not catching, I would go back to the spark/ignition system.

Keep in mind that your brother could have done something else odd, since he was the one to put the battery in wrong to begin with.

Good luck...
 
  #11  
Old 08-30-04, 04:37 AM
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I believe the main relay on that vehicle is under the left side of the instrument panel, basically above your left shin when sitting in the driver's seat.
 
  #12  
Old 08-30-04, 10:51 AM
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Lightbulb

This all sounds interesting, but I have to ask two questions to see if it may narrow your search: Was the key on or ever turned on while the battery was installed backwards? Or did your brother notice the spark when hooking the battery up and realize his mistake (with the key off)?
If the key was off, than wouldn't that limit what components actually had power applied to them? (Opps, third question) I would start looking at fusible links and the main relay. Checking the items I could with a VOM (volt ohm meter).
 
  #13  
Old 08-30-04, 07:59 PM
whlin76
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Trying2Help: 1) The key was not in the ignition when my brother was installing the battery. 2) When he was putting the cables backwards, there were several sparks(with key off) then the sparks went away. That's when he realized that something was wrong.

The Battery Fuse, located in the fuse box under the hood was blown. Before replacing it, when the key was "On" position, nothing happened(no instrument lights, etc.). After he has replaced the Battery Fuse, all the lights and other electrical stuff worked(head lights, emergency lights, heater, etc). When the key is turn all the way to start the car, the engine cranks(Starter working) but it won't actually start the car. I've checked other fuses and they all seemed to be okay.

Any other thoughts?
 
  #14  
Old 08-30-04, 08:51 PM
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You'll need to check if you have fuel and spark. That's the first step. The next step (or maybe the first) would be to check all fuses (and I mean pull them out, and check them with an ohmeter). You could also have a relay be stuck open. Having an electric diagram would help tremendously, along with a basic understanding of how electricity works.

It's pretty hard to damage current ECM's by applying reverse voltage. Most of them are designed to withstand that sort of "abuse". I know most modules I've worked on had to have this protection. In the worst case a diode would fail, usually.

The add thing is that this a 1990 Honda Civic. With the key out of the ignition there should be very, very few things receiving power in the car. ECM may be one, but not likely. The radio will, but it will probably survive. It's normal to have a big spark when connecting the positive terminal to the ground, especially if the car is also somehow grounded (by you touching it for example).

It would help a lot to find out which fuse blew at that time.

On all the cars I've worked on you could not actually connect a batter backwords unless you had the wrong battery in the car. The cables were just not long enough to reach on the other side.
 
  #15  
Old 08-30-04, 09:13 PM
whlin76
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trinitro: I've checked the plugs but sparks. I didn't check for fuel flow myself, but the place my brother took it to initially, claims that he did check and found no fuel flow.

I don't know if this is a significan finding but I've noticed when I unplug the ECU and turn the key "On," all the instrument lights would come on except for the "Check Engine" light. When I plug the ECU back on, then turn the key "On," the "Check Engine" light comes on. Does this mean anything?

Anyway, I've decided to have the 2nd opinion afterall as some of you have suggested. So, I'm taking the car to a local Honda service shop and have them take a shot at it.

I'll keep you all posted on what I find out.
 
  #16  
Old 08-31-04, 06:38 AM
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On that car it's pretty easy to check if the fuel pump has power. That will tell you if the pump itself is bad, or if the relay/wiring before went bad.
What's add is that the pump gets no power with the key off, which would lead me to believe that some kind of relay went bad. I'm not sure if this car has any fusible links, you essentially created a short when the battery was installed backwards.

The "CEL" light should only come on if the ECM is plugged in, only it controls it.
 
  #17  
Old 08-31-04, 07:13 PM
whlin76
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trinitro: So, the fact that "C.E.L." comes on, does this mean that the ECU is working?
 
  #18  
Old 09-01-04, 05:54 PM
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Just cause the check lite goes on dosen't prove anything.

ECU's don't take kindly to reverse polarity. It's pretty neat the way ECU's are designed, they conrol devices by switching the ground.....If the control wire for the device or the device shorts the ECU dosen't care. Usually the fuse protecting the device is on the power side of the device and it blows.

There are no fuses on the ground side of the ECU, so when you power the ECU backwards it has no protection.

BTW is dosen't matter if the key was on, ECU has keep alive power.

There are big power transistors for the injectors that don't like being powered backwards besides all the other transistors, diodes and logic circuits.

The fuse blew because there was a dead short.

Relays dont care which way you power the pull coils. Only way you could ruin one way if what they were controlling was shorted.


Same thing for motors, they would just turn backwards. Thats what you do every time you make you power window go up or down.

Was it one of those "Multi-fit" batteries with the terminals in the middle of the case as opposed to the corners?
 
  #19  
Old 09-01-04, 06:33 PM
whlin76
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toyotaman11769: Thanks for the insight. I don't know what kind of battery it is quite honestly.

Hello Everyone: I just got the car back from my local Honda Specialty shop and it is now alive and well!

Here is what they have found to be problems:

1) The ECU was bad therefore no sparks from the plugs. And one of the four spark plug was dead.

2) Fuel Replay was bad therefore there were no fuel flow.

That's it! The Disbributor and Ignition Switch were okay. All the fuses and relays were fine. No problems with fuel pump or injectors. The total repair bill came to $306.64(including tax)! My brother was quite thrill to say the least. He almost paid that other CROOK close to $2,000 and it still wouldn't have fix the problem!

Anyway, I would like to thank everyone who particated and shared their expertise. In more ways than one, it was a good learning experience for me and my little brother.

Thanks guys!
 
  #20  
Old 09-06-04, 07:20 PM
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Lightbulb

On some cars, the fuel pump relay does not work if you have no spark, so check the ignition before checking the fuel pump operation.
 
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