What causes alternator fires?

[piranah]

What causes the alternator fires? The previous owner replaced the alternator, (aprox 6 months ago) but it was not with a 3g unit.

Since winter has hit, I would like to use the heat for my car, but I am wondering what causes the alternators to catch fire? Am I safe in using the heat, or is it something I should be cautious about? I am getting a winter beater in a couple weeks, so I don't need it for all winter, I just wanna make sure my car won't go up in flames.

[IPreferDIY]

The heat shouldn't be an issue. The heat is from the hot coolant that goes through the heater core in a plastic box (plenum) behind the dash. When you turn the heat on, the air gets directed past the heater core to heat it. So using the heat in itself shouldn't cause an increase in the load on the alternator. If you use the blower motor on high, that would increase the load on the alternator. I don't know the details of what causes the alternator fires, so I'm looking forward to hearing what others have to say.

[L1011tristar17]

From what I stand, the charge passes through a crappy plastic plug, which deteriorates and melts over time. The 3G units have the charge cable bolt onto a metal stud, which will never melt or catch fire. The charge wire on the 3G is thicker too.

[HiFiMerc]

High current also passes thru another crappy plastic connector down under the air intake duct, by the inner fender. That one is prone to salt and water exposure. The one on my dad's '91 literally fell apart when I tried to disconnect it.

[gadget73]

Its heat, but caused by electrical resistance, not under-hood heat. Its more a matter of current load than anything else. If the connector was replaced with the alternator, its probably OK. make sure the connection is clean, and maybe smash some dielectric grease in there to keep it sealed up. If the connector looks like its about to crumble, replace it.

[piranah]

Thanks for the feedback. I really want this car to last till it can be stored.

[85crownHPP]

Yep, somebody at Ford had the genius idea to use push-on spade terminals for a high amp charge connection... Female spades are notorious for opening up after repeated unplugging.
Like they said, as long as it looks pretty new or at least not melted it should be ok. You could feel it for heat, as long as its not hotter to the touch than the case of the alternator it's good. Touch with caution if your fingertipss aren't calloused up like mine.

The 3G swap can be cheap and easy if you want to add it to your project list

[piranah]

Its on the list. Just not wanting to spend $ before I store it.

[porschpow]

It looks like you have the upgraded charging system.

Would you be able to show some photos of what your system looks like. I will be doing mine soon.

From what I stand, the charge passes through a crappy plastic plug, which deteriorates and melts over time. The 3G units have the charge cable bolt onto a metal stud, which will never melt or catch fire. The charge wire on the 3G is thicker too.

[ATTACH=CONFIG]41431[/ATTACH] [ATTACH=CONFIG]41432[/ATTACH]

[L1011tristar17]

I posted a thread when I did the swap a year or two ago

http://www.grandmarq.net/vb/showthread.php?48019-Finished-with-3G-swap!-(pictures-included)

The swap is pretty straightforward. The new alternator fits into place with a different sized nut and bolt (the top hole on the 3G isn't threaded like the 2G). Charge cable runs from the battery (with a 175A fuse) to the post on the 3G. Grab that charge cable and the wiring pigtail for the voltage regulator from a Taurus in the junkyard. The green wire connects to the AMP light and gets soldered. That's essentially it!

[porschpow]

THANKS! Well done.
How are the lights?
No more dimming?
Where is the amp light that the green guy goes to?
So you had to get a new belt, eh? 505k6 belt (same size as a 2000's Escort)



Good thread.

I heard from a guy that runs an alternator/starter shop that the 2g's were a big problem. They threatened Ford with jacking up insurance premiums if they didn't fix this.

I apologize for thread jacking!

[gadget73]

Its the idiot light in the dashboard that says AMP, or maybe its Batt. Whatever the "yo dawg, yo shit is gonna go dead" light happens to be.



The lights don't dim anymore with an alternator that doesn't suck. I have underdrive pullies on my car and they still don't dim.

[L1011tristar17]

Look up 3G conversion threads. There are tons of them and several have wiring diagrams, which make it even easier to visualize the swap. The lights do dim a little if the subwoofers are going, but it is barely noticeable. The JY alternator I got two years ago is still going strong.

If you want to retain the original belt size, you can always swap the 2G pulley onto the 3G.

[pantera77]

Ya 2g's aren't just fired hazards due to the stupid connections, they also just suck in general.

[porschpow]

nice!