Please HELP me identify this blown component!!!

I have been having car trouble lately. /ubbthreads/images/graemlins/icon23.gif First the A/C and power steering belt broke, then my battery died. I charged the battery and the car was (or seemed) fine the next day. I drove it to work and all was well.

Yesterday, it was dead again. /ubbthreads/images/graemlins/mad.gif I was going to put the charger on it and try to drive it to work, but something weird happened.

First, some details about the charger: My charger is a Schumacher electronic charger. It has 6v/12v capability, automatic/manual modes, plus a 50A engine start mode also. I had it set on the 2A, 12v automatic mode (can push as much as 14A here on a dead battery, but trickles at around 1-2A).

I put one clamp onto the battery, and as soon as I attached the other clamp, the charger groaned and souned like it was being shorted. Before I could even unhook the clamp (less than 1s), something blew in the charger and sent sparks flying. The charger was dead after that. /ubbthreads/images/graemlins/frown.gif /ubbthreads/images/graemlins/jpshakehead.gif

Anyway, upon disassembling the charger, I discovered what had blown. As far as I can tell, it was either some kind of thermal switch, or some kind of current limiter. It was pushed down in a hole inside of the plastic housing that the transformer wires are wrapped around, and unfortunately, I can't get the rest of this stupid thing out. The harder I tried, the further in I pushed it. Anyway, here are a couple of pictures:


Click for Fullsize(or if pic isn't showing up)



Click for Fullsize(or if pic isn't showing up)

This component is inline (in series) with one leg of the 120v AC input to the transformer. Because the part has blown, power is not getting to the transformer, thus why the charger has died. The charger input is rated at .5/2/9.1A. If I'm reading this part correctly and it is rated at 2.5A, 250v so I'm not sure how they can rate the charger for 9.1A at 120v AC. /ubbthreads/images/graemlins/thinking.gif

Anyway, any help that anyone can offer me would be appreciated. I realize that I could probably jump across the part and still use the charger if need be, but I'm sure this thing is probably a safety device and would thus be defeated. Any further issues could then cause damage to more expensive parts like the transformer itself. I know we have some power supply guys here, and I'm hoping someone recognizes this part (or what is left of it).

Thanks!!! /ubbthreads/images/graemlins/bowdown.gif /ubbthreads/images/graemlins/wink2.gif

LEDmodMan,

I can get this identified pretty soon, but at this point I would suggest that you do NOT jumper this component.

Also, I know it hurt$ but you probably will have to replace the battery, given the givens here.

I just returned a Schumacher electronic charger 100A as it did the exact same thing! I took it back to Wal-Mart for an exchange. I only had the original one for approx. 1 month & used it very little before it blew.

LEDmodMan,

Well, I don't have a certain answer, but it's a pretty good guess that this is an inrush current limiter. One of my fellow operators and I went through some catalogs trying to find that T w/ over-bar logo and which company belongs to it, but no luck so far. Again, I would be vary wary of jumpering out this component.

Probably Illuminated will be able to ID this for sure. Sorry I couldn't be of more help.

Jim,
Thanks for your help!!!

Ya, I figured it was some kind of current limiter. I am wary of jumpering it, but I would really hate for the charger to be trash. I bought it at Costco around 6 years ago (I likely still have the receipt too), and it has worked very well until yestrday. If I can't fix it, I wonder if they would still honor their return policy /ubbthreads/images/graemlins/naughty.gif (would be a test of just HOW good their return policy is I suppose)?

I wish I could get the remainder of the component out of the little hole as it might provide some more clues. I tried tweezers, and even they were too big to get to it. The only other way I can think of is blowing some high-pressure shop air into the hole. That might blow the part up out of it, however I don't have access to any. I'll have to see where I could get some.

Oh ya, I agree that the battery might be toast too. /ubbthreads/images/graemlins/frown.gif It was reading no voltage before and after this whole mess with the charger. I then took the car's connectors off of the battery, and the voltage began climbing. So the bad news is that the battery has now been deeeeeeeep discharged, so it might be trash anyway. At least the batt. was bought at Costco less than 2 years ago. They have a 100 month pro-rated warranty on their 12v car/boat batteries, and with the low initial cost of this battery I doubt I would have to pay more than $10 for a new one.

The really bad news is that I have some kind of short in the car! /ubbthreads/images/graemlins/rant.gif No lights are turned on that I know of, so it really going to suck finding that now. /ubbthreads/images/graemlins/icon23.gif /ubbthreads/images/graemlins/smoker5.gif /ubbthreads/images/graemlins/sick.gif

Hello there,

That's a Thermal Fuse with the following specs:

2.5 amps
250 vac
150 degrees C

It blows on either too high a temperature or too high
a current through the device.

If this thing was not mounted right up against something
that gets hot you could substitute a 2.5 amp fuse for
testing.

Also, i probably have one of these lying around if
you live in the USA send me (PM) your address and i'll
mail you out one.

Unless something else went wrong the reason it blew could
be because something else about the charger isnt working
correctly anymore. Of course it could have just
been because of a very bad battery.

Take care,
Al

EDIT: An electro expert (MrAl) was faster /ubbthreads/images/graemlins/bowdown.gif

I'm no electro expert, and I have problems understanding Chinese /ubbthreads/images/graemlins/smile.gif, but according to this page, it seems like it's a "thermo protector". I don't know if this helps... Good luck!

OK guys, THANKS!!! So it was a thermal/current fuse! Dang, I must have actually learned something in my electronics classes /ubbthreads/images/graemlins/yellowlaugh.gif, as I thought it might be one of these two things!

MrAl, it was stuffed down inside of the plastic transformer coil housing. What's weird is that there is another much larger metal-cased device (under the tape at the bottom of the picture) stuck to the outside of the primary transformer coil that I figured was a thermal fuse as well. Maybe this thing has double thermal protection (temp inside and outside of the transformer)? PM on the way.

hacky, I think you found the exact part there! The part has a U25 printed on it, and U25 on that spec sheet you listed matches the specs of the device. Thanks! /ubbthreads/images/graemlins/thumbsup.gif

It would apppear that you have some kind of constant drain on your battery. Probably it's over the 9.1 Amp maximun that your charger can deliver, therefor blowing the fuse. Look for something that is staying on all the time in your car..like a light(glove compartment) or something else. It's not a dead short. Could be bad diode in alternator too.

Hello again LEDmodMan,

I checked and i have the part, but it's 115 degree C
part that's the only difference, but if it were my
battery charger i would want something lower
then 150 deg C anyway. 115 deg C means it will
be even safer to operate.

Your address info has been noted and i'll get the
part out to you tomorrow morning in the US mail.

Of course there's no charge so dont worry about that

One thing you should note before you start the repair.
You should really check to see if there are any blown
diodes in the charger or anything else that doesnt
look right. Before you use the thermal fuse you should
also try to run it with a 'regular' fast blow 2.5 to 3 amp
fuse. If it works with that it will work with the
thermal fuse. If it blows the fuse then obviously something
is still wrong and should be corrected before installing
the thermal fuse because the thermal fuse will just
blow out again if something is still wrong.

Also, when the thermal fuse is finally replaced, you should
try to get it into the exact position the original was in
and if it was touching something it should be touching
whatever it was -- you probably know that already

You'll should see something in the mail around
Friday.

Good luck with it!

Take care,
Al

Guys,
Thanks!

rdshores: I'm sure whatever is draining the battery is not doing so at greater 9.1A! I would worry about a fire at that rate! It is a much slower drain than that. I have already checked for bulbs so it is something else. It may very well be a bad alternator diode (I've had past trouble with those).

MrAl,
Thank you sooo much for the thermal fuse!!! You're right, 150 deg C is a bit high, would already probably have damaged the charger by then. 115 deg C should work fine. I'll double-check it with a 3A fuse before re-installing the thermal fuse, since I know I have some of those on hand. I checked many of the other parts on the charger, and everything else seems to be OK.

Thanks again to everyone who helped me out here! /ubbthreads/images/graemlins/thumbsup.gif CPF RULES!!! /ubbthreads/images/graemlins/bowdown.gif

Hi LEDmodMan,

Personally, I'd check it at a lower output with a 2A fuse just to be on the safe side. If it's incorrectly pulling >2.5A<3A then the 3A fuse wouldn't blow, but the thermal fuse would. A 2A fuse would probably be a bit safer and show that the 2.5A thermal fuse wouldn't blow instantly.

Also, it looks like that tcofuse.com site that hacky found was right on the money. Here's that "triangle-T" picture directly from the website.

It came off of this page. The first link on that page takes you to the same page that hacky posted.

pb

EDITED:
This board doesn't seem to like [image][/image] tags for images with a 4+ character extension. Like .jpeg instead of .jpg

Hello again,

LEDmodMan, your Thermal Fuse is on it's journey to your
hometown Keep an eye on the mail.

pb: that's a good idea...a 2 amp fuse should be just fine
for testing, then if it works ok use the thermal fuse.

Take care folks,
Al

So why did the charger fuse blow in the first place? You are going to have to track that down to solve the problem.

The plan is to find out what is wrong with the car tomorrow. I have a plan of attack for this in mind already.

I hope it's not too much work, or else the car is going to the junk yard!!! /ubbthreads/images/graemlins/icon15.gif I've had it with this car! (but I've been threatening to junk it since March) It's 20 yrs old and served me well for 5 of those years. I have definitely gotten what I paid for out of it and then some...

The charger is a seperate problem that I believe only happened because of the problem with the car.

MrAl, I got the component in the mail on Sat. Thank you!!! /ubbthreads/images/graemlins/bowdown.gif /ubbthreads/images/graemlins/thumbsup.gif /ubbthreads/images/graemlins/clap.gif The charger is now fixed and working properly!!! /ubbthreads/images/graemlins/grin.gif

Update:
After about three hours of working on the car, I finally found the short. The problem was in the headlight switch in the steering column. On this car, as is on many I have had experience with before, when you pull back (toward you) on the headlight/turn signal switch, it activates the car's high beams temporarily. When you release the switch wand, it springs back and the lights turn off.

Apparantly, something was catching in this switch and there was a slight short there to the left headlight. The headlights are retractable, so I didn't see the light turned on. Anyway, the switch was disassembled and fixed. What sucks is that I have had to work on this switch before (but because the lights wouldn't turn on)! /ubbthreads/images/graemlins/icon15.gif

Talk about a PITA to find this short though! It was such a pain because the temporary high beam switch is direct-wired to the battery, with only a fuseable link in the circuit path to prevent too much current. I had ALL of the fuses pulled out of the fuse box, and everything else I could think of disconnected. I was still reading a short on my DMM. What the heck? /ubbthreads/images/graemlins/confused.gif /ubbthreads/images/graemlins/thinking.gif I was sooo confused/frustrated. I finally had to start opening the wire harnesses to find out where the problem child wire was! /ubbthreads/images/graemlins/eek.gif Only then did I discover a little box of fuseable links hidden away under the air filter box! /ubbthreads/images/graemlins/mad.gif Then I was finally able to isolate the shorted circuit. I hate electrical problems on cars!!! /ubbthreads/images/graemlins/rant.gif

Anyway, during my electrical quest this past weekend I also found a broken wire going to the regulator in the altenator, which explains a quirk that this car has had since I bought it: I used to have to rev the engine to about 3500-4000 RPM before the alternator would kick on and start charging the battery. This car has an all-digital dash, which includes a battery monitor setting. Shortly after buying the car, I was driving it and the engine just died at a stop sign. I checked the batt. and it was down to about 4v!

After re-charging the battery, I got in the car and started it while watching the batt meter. It only showed 12v from the battery, not the ~14v I expect to see from the regulator on the alternator. I started driving, and noticed that just prior to the shift from 1st to 2nd that the battery meter climbed from 12v to 14v. /ubbthreads/images/graemlins/thinking.gif I finally realized that the engine had to be revved up enough to get the voltage in the alternator to a high enough point that it would engage and start charging the battery. It's been like this for 5 years, and I've never bothered to fix it since I knew I just had to rev the engine a bit to get it working. Problem solved now though... /ubbthreads/images/graemlins/yellowlaugh.gif

Ok..let's summarize. Your headlight switch stuck on and ran your battery down. You didn't notice the headlight was on. You tried to charge the battery using the 2amp charging position (with the battery still hooked up)and blew out the charger fuse by trying to power your headligh(a several amp load). That's why the fuse blew. Now I can relax.

Hi again LEDmodMan,

That's great news! You're welcome, and im glad you
could get it up and running again. I hope it lasts
you a very long time now.
Sounds like you've got the car circuits under control
too


Take care,
Al