New alternator (2G) hot again!

[mfmagicmike]

Hi!
I am the happy owner of a black 1989 Ford LTD Crown Victoria Lx (302 CID SEFI). Since the car is pretty old, and since the original alternator started to become noisy (probably worn bearings), I replaced it with an identical 65 amp alternator (2G).
Since then, on one hand the output seems better(brighter lights, heating works longer), but on the other hand, it still seems too low for the car, the (new) battery discharging after prolonged heating or the use of the rear window defroster. As the ouput of the alternator is apparently too weak for normal use, I suspect the car of using battery power to do the job, and as it is discharging, the alternator has to work permanently at maximum output, causing it systematically to overheat.
So here is my question: Do You think there is a default in the electrical system of the car, or is the alternator simply too weak to supply the car correctly (and that would mean that Ford sold hundreds of thousands of cars in which it is impossible to put on heat for more than 10 minutes - which can be sort of a problem in winter)?
Thanks for Your advice ++

[gadget73]

what condition is your battery in, and how good are the cables? The stock alternators do blow, especially at idle output, but that seems a little extreme. On the other hand, the blower motor circuit does use a 30 amp fuse, on high its probably pulling an easy 20-25 amps. Rear defrost is probably another 5-10. With the low output at idle, I can see a situation where you'd be discharging the battery after a while.

You may want to check out the condition of the wiring harness at the alternator. Often those will make a poor connection and cause poor charging, fires, and alternator failure.

[85crownHPP]

yes replacing the plug with the alt is a must!!!!!

[interceptor1985]

or replace the intire thing with a 3G alternater and live happely ever after.....???just a thought

[mfmagicmike]

Off course, the 3G alternator sounds like the best solution. Even new, the 2G alternator seems to be too weak for the car: it barely supports the rear defroster running at the same time as the ATC fan. Even when I only turn on the 2 strobes I've got, the cabin lights start flickering.
I hesitated for the 3G when I bought the new one, but I didn't feel confident enough for doing the wiring and fuse links (I like to work on things I can see, (i.e. bolts, screws,...), - unlike electricity).

I went through all the wiring yesterday, and found all the fuse links (close to the alternator and to the starter relay besides the battery), and they don't look to bad. I cleaned all the connectors, and wire connexions. I hope that'll do.

About the wiring harness at the alternator:
The small voltage regulator plug looks good, like new.
The big plug is OK on the outside, but the interior insulation (white plastic or equivalent) is starting to crumble. Your advice to change it ASAP, sounds like a very healthy idea to me.

[interceptor1985]

hmmm Alternator problems sounds like a perfect reason to upgrade to me 3G's are safer too....so I have heard.

[portdizzal]

i just swapped to a 86' mustang alternator. i think it was 110-140amps i dont remember but i have no problems with two air pumps, all the audio, and headlights on. Optima gell cell is a must.

[interceptor1985]

my red top died...wont hold a charge...I'm pissed

[mfmagicmike]

I checked the alternator output and the wiring integrity - everything is working fine. And since my battery is new, and also the battery cables, it must be that the 2G is too weak.
I found a Mustang 3G alternator that should do for a swap.
What amperage should I take: 95 or 130 Amps?

[gadget73]

130. go big or go home

[86GmLsCoupe]

Get the 130, anything worth doing.. I just put a 95 Mustang (5.0) alt in and it's 130 amps. They have the same alt in other cars but everyone remembers the Mustang application. This is the smaller sized one that you'll need (7inch) and it fits right into the stock bracket without any mods. I haven't wired mine up yet, but I can tell you when upgrading there's some minor rewiring and you MUST change the charge cable. You'll also probably want to upgrade your grounds though not everyone suggests it, I'm doing mine. Here's a link to some info about the 3g upgrade, I also picked up my charge cable and harness here. http://www.fordfuelinjection.com/ind...&submit=SEARCH

[mfmagicmike]

Thanks for Your valued advice and link!

[86GmLsCoupe]

No problem, hopefully the rest of my cable/parts will come in and the weather will cooperate so I can actually finish the conversion. I've heard nothing but good things about going 3G, people say it's of the best upgrades you can do on these cars. I'll report back soon and hopefully have tons of pics and some more insight into it.