I recently bought a 94' Black/Tan SC400 and I'm loving every minute of it until the problems started. For three weeks it ran perfect with absolutely no problems, but about a week ago when I tried to turn it on in the morning, the battery was dead. Dim dash lights ,no horn, steering wheel did not move, etc etc. After several attempts to jump it, it finally worked. To make a long story short, this continued until I took it to a mechanic. I found out that the battery was fine (after a good charge), the alternator was fine, all fuses seem to be fine, the starter would need to be replaced soon(but not right now, is not causing the problem). My mechanic did find that the cig lighter seemed to stuck on, he cleaned out the hole and took out the lighter itself.

We all thought that this was the problem, and that everything should be fine again, but after two problem free days (better than before) the car wouldn't start again. Just clicks when I try to turn it over.

Also the factory alarm goes off sometimes if the door is not shut firmly (door sensors?), but I've never heard it at night and I make sure to close it extra hard at night. Only heard it go off during the day like twice, and I immediately shut it off those two times. Can this be a problem? Is there a valet switch or some easy way to turn off the alarm.

No after market electronics in the vehicle. (At least not yet)

Any suggestions?

Thanks

 

Sounds like dead battery (needs to be load tested after charged), bad charging system (easy to check), bad connection(s) (check fuse/Relays, all connections hot & especially grounds), or something else pretty obvious like these things.

Good Luck,

Tim

 

Both the battery and the charging system are not the problem according to two separate mechanics. And I don't think a bad connection would drain the battery. Something electrical seems to be draining the battery overnight. Are there any suggestions of what it might be. (I know its not the headlights, interior lights, or anything else extremely obvious)

Thanks

 

there is one other thing you can check and its the door ajar sensors those could be causing a draw on the system too .... looks like your gonna have to hunt for where the power is going to when you have the key off hope you got a multimeter

 

Can anybody tell me a quick step by step of how to disable the factory alarm system? This might be the problem causing the drain but its not functioning correctly anyways so it doesn't matter if I disable it.

Thanks

 

other than find the fuse and pull it??? or put in valet mode?

 

Ahh.... How about, buy a battery!

 

Uhhhh, the battery is fine. Something is draining it.

How exactly do you put it in valet mode? I've read that there should be a black switch or something under the dash. And while in valet mode the alarm should not be able to off at all, correct?

 

How exactly did your 2 mechanics check the charging system?
You probably have a bad alternator. I'd start by taking the battery to an autoparts store, and have them check for a bad cell. If that's not the case, take the alternator to them for a check also. This is pretty much a common procedure that people have to go through first before eliminating anything.

 

it's to the right of the gas door/trunk lock mechanism.

I'm actuall having the same issue, i'm going to try this:

http://www.ehow.com/how_2249402_find...paign=yssp_art


hope i helped.

 

The battery and charging system are perfect.

The switch to the right of the gas door/trunk lock mechanism turns the keyless entry off. Anyways, that switch has been in the off position the whole time and the alarm still goes off.

Which fuse (and where: under dash, under hood,or both) should be pulled to kill the alarm system? And does this fuse effect anything else in the car?


Thanks

 

i usually assume people check their own battery and alternator ...he can check both at same time just needs a hand while doing it and all with a multimeter.... check at koeo and see the voltage of the battery before start it not the drop then see where the voltage sits depending on the voltage sits he'd get an idea if its bad or not... after that when the battery is charged up he can shut it down and watch the numbers of the battery at koeo and if it is draining at a steady rate with all electronics off then he has a parasidic draw somewhere

 

Ok, I had an after market alarm installed yesterday to override my out of whack factory system. It works fine, and the alarm shouldn't go off randomly anymore I'm just crossing my fingers that it was the alarm that was draining the battery in the first place.

 

Update:
Okay, the battery is still being drained so I've been diconnecting the positive terminal on the battery overnight. I've also put the alarm in valet mode to avoid any unecessary headaches. Everytime I connect the battery in the morning it starts fine with no problem.

One time when I left the battery connected for a couple a days I went outside and I heard a constant clicking comnig from the door panel (lock mechanism?). When tried to start the car it was completely dead. Now, is it the lock mechanism's continuous clicking that kills the battery or is it the weak battery (already drained by something else) that is causing the locks to whack out)? Also sometimes when i start the car power locks click twice but stay unlocked instead of locking like they're supposed to.

Any answers or suggestions are greatly appreciated.

 

You might have a short somewhere. Some kind of unwanted ground. Try checking the voltage between battery + terminal and the body while the - batt terminal unplugged.

If you get voltage, you probably have a short and is causing current to flow to things when it should not.