Urgent! Fire! Help!

[DRKSD]

Please please please somebody help me out here.

I was just working on my mustang, removing the red extender from the plug that goes from the alternator to the battery to give the needed clearance underneath my hood after relocating the alternator for the trick flow intake manifold, then when I went to re-connect the battery, these two cords that connected to my fuse box caught fire.

I'm assuming since one is green it was a ground, (hopefully) what is the other one, why did this happen and how the heck can I fix it????





Here is how the plug connected once the extender had been removed.




Somebody please tell me I didn't just fry my entire car with this screw up?

 

[wmburns]

Looks like the fusible links have been burned up. The fusible links are designed to protect the system from a direct short.

Depending upon how good your electrical is, it's possible to splice in replacement fusible links. The factory method has the entire battery cable to be replaced. Much better than having the entire car burned down.

Note to self. Today's car's have tons of "always on" circuits. Always disconnect the battery negative when performing electrical work.

 

[DRKSD]

Thanks for the quick reply. Is there somewhere that I can determine what size of fusible link I need to get to replace these?

I had the battery disconnected, the link burned up immediately after I reconnected the negative to the battery.

I'm guessing perhaps when I reconnected the wire to the alternator it was grounded to the alternator somehow? otherwise I'm not sure what the cause of the short could have been?

 

[wmburns]

Try contacting your local autoparts store. This should also be an item that's easy to find in the salvage yards.
http://www.oreillyauto.com/site/c/d...odel=Mustang&vi=1362743&keyword=battery+cable

 

[DRKSD]

I just had one other question, there are two wires that burnt through, does that mean that there are two fusible links attatched there, or is one of those simply a standard wire and if so what does it go to?

 

[wmburns]

The two wires work together to form the fusible link. I suspect that two are needed to carry the required current.

 

[DRKSD]

Roger. That's what I was thinking as well after further examination. Have ordered new cords, hopefully will have the car back in functioning order before the weekend.

If anyone is still looking at this thread, any suggestions as to why this happened? My concern is that even if I do replace the fusible link, what's to stop it from shorting again? The only thing I changed was removing the extension from the alternator charging cable, but it was instructed in the trick flow install manual to do that. From the picture posted did I do something wrong when re-installing that cable without the extension?

 

[wmburns]

From the picture posted did I do something wrong when re-installing that cable without the extension?

Do I even need to answer this?

Unless I'm missing something, the lug has been re-clocked. Remember that the motor does move/turn in the motor mounts. What's to prevent the lug from grounding out to the alternator case in it's current configuration????



If insisting on keeping it like it is, at least wrap three layers of electrical tape around the lug.

OBTW, don't be surprised if the alternator doesn't work once everything gets put back together. The fusible link protected the car from burning to the ground. The alternator would have still been exposed to the full force of the short for the entire time.

 

[DRKSD]

Do I even need to answer this?

Unless I'm missing something, the lug has been re-clocked. Remember that the motor does move/turn in the motor mounts. What's to prevent the lug from grounding out to the alternator case in it's current configuration????

I'm not trying to be a pain, and I am very grateful for your assistance. I freely admit that I have no mechanical expertise or background. I just want to get my car back on the road.

I don't understand what you mean when you say that the lug has been re-clocked?

The extent of the work that has been done in reference to the Alternator is as follows:

The alternator was moved via the trick flow intake manifold relocation bracket, which re-mounted the alternator facing the other direction to make room for the lower portion of the intake manifold.

After driving for a few days I noticed that the cord in question was pressing against the hoodliner and was starting to melt its way into the hoodliner. It was then that I looked back through the instructions and noticed that when the Alternator was re-installed, my nephew and I had forgotten to remove the red extension portion that the eyelet was bolted to, which in turn bolted to the alternator.

So the other day, I removed that red extender, and then bolted the eyelet into place where the picture shows, then pulled the rubber cover back overtop of the eyelet.

Here is the step on trick flows instructions:

16. Install alternator with supplied brackets. Re-use OE bolts to mount TFS main bracket to block and TFS upper alternator bracket. Use (2) HEX FLANGE BOLT M8 X 1.25 X 35mm to attach the cut out spacer to the main bracket from the backside of the main bracket. Use the supplied 40mm and 120mm HEX FLANGE BOLTS to mount alternator. Place belt on top of spacers before installing alternator to bracket. Remove red extension post for battery on alternator, re-attach battery wire. For NA (Naturally Aspirated) applications the bracket should be positioned toward passenger
side. For Supercharged applications brackets can be adjusted for clearance.

NOTE: On some vehicles/applications it may-be necessary to trim/grind thepower steering pump reservoir bracket for belt clearance.

http://www.musclemustangfastfords.com/tech/mmfp_0712_trickflow_intake_manifold_install/photo_05.html
This image shows the alternator with the red extension still in place as it's being removed.

http://www.musclemustangfastfords.com/tech/mmfp_0712_trickflow_intake_manifold_install/photo_27.html

http://www.musclemustangfastfords.com/tech/mmfp_0712_trickflow_intake_manifold_install/photo_28.html

And these two show the Alternator re-installed without the red extension just as I did.

So, again, I do apologize for my lack of mechanical understanding, I certainly would not have undertaken this particular step on my own initiative simply thinking it would be a quick fix. I only did this because it was outlined in the instructions to do so, and I have the pictures from that article in Muscle Mustangs and Fast Fords to go off of in terms of a comparison.

 

[wmburns]

The pictures on the MM&FF sites shows that the red insulator is still in place. From your pictures it has been removed. What do you think the purpose of the red insulator is?

From the pictures posted of your motor, it appears to me there is very little clearance between ring lug and the alternator case. With the red insulator removed, what is keeping the metal of the ring lug from touching the alternator case?

Electricity doesn't care if you followed the instructions or not. All it cares about if finding the path of least resistance. Bottom line, there is someplace that the insulation has been compromised or omitted. The proof is in the burned up fusible links.

 

[n0v8or]

As is usually the case, I am in agreement with everything Burns posted. For what it is worth, I thought I would answer some of your questions that were not specifically addressed.

Where do the black/orange-stripe and light green wires go?
You did not specify model year. On my '03, the black/orange is the main charging wire, and goes to the big lug on the back of the alternator, where the insulated spacer was removed. The light green wire is battery voltage sense, and goes to the 3-pin connector on the back of the alternator.

What does re-clocked mean?
It is a term commonly used by military techs to describe a change in angle. In your photo of the alternator (original post, 4th photo), the lug is bolted such that it exits the alternator at approximately 4 o'clock. The safe zone is between 10 and 11 o'clock. Any other angle risks a short to the alternator case, which is ground. In your image, the short looks to be there already . . . but pictures can be deceiving.

Where is the short?
The insulator/spacer limits the angle of the charging wire and spaces it a safe distance from the alternator frame.
To remove the insulator, did you have to remove both nuts on the stud, or just the outer one? If both had to be removed, you may need a fiber washer between the lower nut and alternator case to prevent a short.
Another possibility is the stud rotated during removal of the insulator/spacer, possibly causing a short to develop within the alternator. Finally, the insulation may have been compromised somewhere between alternator and battery positive, and the bare wire is coming into contact with ground.

How to prevent burning up another fusible link?
Do not reconnect the negative battery terminal until you know the short has been cleared. There are numerous methods to determine this. In my opinion, the safest is a "low tech" test light. At a wrecking yard or parts store, buy a brake lamp socket with wires, and a brake light bulb to fit in it. These bulbs are usually 21 watts and will draw about 1.5 Amp. Strip about 1/2" of insulation from the free ends of both socket wires. With the ignition off, hold one socket wire in contact with the negative battery terminal and the other to the (still removed) negative battery cable. If the lamp lights to full brightness (touch the socket between + and - battery terminals to get an idea of how bright that is), the short is still there. If the lamp lights more dimly, you have less than 1.5A of ground current, meaning the short has been cleared.

If you get a bright lamp, remove the big lug from the alternator, and try again. If the short still remains, inspect the entire length of the charging cable for damaged insulation near or in contact with a ground.

Report back, and Burns or I will try to guide you from there.

 

[DRKSD]

Thank you for the added clarification, you have both been immensely helpful thus far.

The model year is 99.

What does re-clocked mean?
It is a term commonly used by military techs to describe a change in angle. In your photo of the alternator (original post, 4th photo), the lug is bolted such that it exits the alternator at approximately 4 o'clock. The safe zone is between 10 and 11 o'clock. Any other angle risks a short to the alternator case, which is ground. In your image, the short looks to be there already . . . but pictures can be deceiving.

I see what you're saying here. I've noticed now that in the pdf that trick flow provides, they have the lug bolted at the 11 oclock angle, which contradicts the photos that I was working off of in the MM&FF article which pictures the lug bolted at the 3/4 oclock angle. The reason I had attempted to bolt it at the angle I did, was to get the ensure clearance underneath the hood. Obviously in hindsight, I was so concerned with ensuring proper clearance away from the hood that I did not pay close enough attention to the clearance between the lug and the Alternator itself.

Where is the short?
The insulator/spacer limits the angle of the charging wire and spaces it a safe distance from the alternator frame.
To remove the insulator, did you have to remove both nuts on the stud, or just the outer one? If both had to be removed, you may need a fiber washer between the lower nut and alternator case to prevent a short.
Another possibility is the stud rotated during removal of the insulator/spacer, possibly causing a short to develop within the alternator. Finally, the insulation may have been compromised somewhere between alternator and battery positive, and the bare wire is coming into contact with ground.

I removed only the outer nut. the larger one remained in place.

Tomorrow once I have some daylight I will try to take some more/better photo's to help illustrate the situation.

 

[DRKSD]

Alright guys. Here are some more pictures. I re-used the nuts that were on the extender in the fashion pictured above in an attempt to create some more clearance between the connector and the alternator itself.

I also 'reclocked' the lug to the more appropriate 10/11 oclcok position in relation to the alternator itself.

We soldered in the two 12 ga fusible links with the green and the black/red wire and reconnected everything to the fuse box and battery. No smoke or fire, car started up fine.

But ofcourse, Battery light is on.

So I'm again at your mercy here. How best can I go about checking to see if it is the alternator itself that is bad, the voltage regulator that is bad, the connection we just soldered, or any or all of the above?

Again, thank you very much in advance for any help or advice you can share.

 

[n0v8or]

Good idea to increase the spacing with another nut. Looks like thee is plenty of clearance in your new pictures.

Battery indicator 'on' means undervoltage, overvoltage, or no stator output from the alternator.
First, look for a fuse in the box under the hood marked "ALT". I think it is 20A. If blown, the alternator will not function.

To test further, you will need a voltmeter. The cheap digital ones sold by Harbor Freight for $3 will do fine.
With key off, measure DC volts with negative probe contacting the alternator case and positive probe contacting the big lug. Should read battery voltage (~12V). If not, your new fusible links are not completing the circuit.
If OK, push the positive probe into the back of the regulator connector where the yellow/white wire goes. This is the field terminal and it should also be at ~12V. The ALT fuse protects this wire.

If both voltages are OK, start the car and see if the voltage between the two battery terminals increases to 13V to 15V while the engine is at idle. If not, the alternator is not working.

 

[mransr]

I suspect wmburns is right and the alternator is smoked too; assuming there are no blown fuses anyway. When a fusable link burns out something else almost always fails first...

I know it's a PITA, but it probably would be a good idea to take the alternator out and have it checked before pulling your hair out trying to chase down gremlins...

 

[DRKSD]

Good idea to increase the spacing with another nut. Looks like thee is plenty of clearance in your new pictures.

Battery indicator 'on' means undervoltage, overvoltage, or no stator output from the alternator.
First, look for a fuse in the box under the hood marked "ALT". I think it is 20A. If blown, the alternator will not function.

To test further, you will need a voltmeter. The cheap digital ones sold by Harbor Freight for $3 will do fine.
With key off, measure DC volts with negative probe contacting the alternator case and positive probe contacting the big lug. Should read battery voltage (~12V). If not, your new fusible links are not completing the circuit.
If OK, push the positive probe into the back of the regulator connector where the yellow/white wire goes. This is the field terminal and it should also be at ~12V. The ALT fuse protects this wire.

If both voltages are OK, start the car and see if the voltage between the two battery terminals increases to 13V to 15V while the engine is at idle. If not, the alternator is not working.

Ok I checked the First one, Negative probe contracted the alternator case, positive probe on the big lug, got slightly over 12V there.

Pretty sure I tracked down the field terminal and it also showed proper voltage. I guess all that boils down to the alternator being bad. I'll tear it out tonight and take it by a local shop to have them test it to be sure.

Thanks again you guys for all the help.

 

[DRKSD]

I suspect wmburns is right and the alternator is smoked too; assuming there are no blown fuses anyway. When a fusable link burns out something else almost always fails first...

I know it's a PITA, but it probably would be a good idea to take the alternator out and have it checked before pulling your hair out trying to chase down gremlins...

I definitely don't disbelieve his suggestion. I'm just hoping to make sure that the connectors and the regulator are both in working order so that If I do order a new alternator, it can just plug right in, instead of then having to track down where the *other* problems were.

 

[wmburns]

The 99-04 Mustang charging system uses fuses F1.20 and F2.5. Confirm that the fuses are good. Not a bad idea to confirm there is power in the supply side of the fuse with the key on.

Here's the layout.

http://www.allfordmustangs.com/foru...r-swap-wont-fire-please-help.html#post2669271

If the fuses are confirmed OK, then with only 12 volts on the alternator main B+ terminal, the alternator is not charging.

FWIIW, the alternator can be tested on the car. Most auto parts stores will do it for free.

If the alternator is bad and $$ is tight, consider a salvage yard replacement. The Mustang's GT alternator is stupid easy to change. I paid 40 bucks for my last salvage yard unit and two years later it's still running strong.

Try car-part.com for a searchable list of salvage yards in your area.

Kudos on your work! It looks much better! The extra tape up the length of the main cable looks professional as well.

 

[DRKSD]

Ok, new alternator is installed, car is running fine. I don't have pictures yet but its basically the same setup/angle as the last set of pics I uploaded, with the plug at about 10/11 oclock position. That black wire is still pressing into my hood liner when the hood is closed and the heat from it is melting through the hood liner still.

What else can I do here to fix this?

 

[mransr]

wait...a wire is getting hot enough to melt the hood liner? ...I'm not an expert on electrical systems, but I think something is still very wrong with the wiring