Batenswytch

The alternator on my 91 5.0 conv. is crap. We had it rebuilt this last summer, 'tweaked', etc by a local alternator 'wizard' (it was sucking the life out of my battery) and still my headlamps are dim (to the point its hazardous to drive after dark unless you've got them on high-beams), my dash lights are dim, all interior lights are dim, the power windows and convertible top controls are sluggish (could be a motor problem there, but I got to wonder...) and now I'm wanting to put a serious sound system in it and I'm worried it won't put out enough juice to power it.

I was told by a guy at a car show that the alternators were weak on the Fox bodies, but if I would take alternator from a 94 and swap out the pigtail that it would bolt right on and voila!

Anyone tried or done this? Could you let me know if it's just that easy? I have no intention of going through the hassle only to find out 'that guy' was a moron and didn't know what he was talking about.

Could the dimness of the lights be caused by something else? FYI - I have brand new headlights and the protective panel over the gauges has been taken apart, cleaned, and buffed so it looks brand new, so its not just a 'dirty lens' issue.

FivePointOhh

it was easy swap. well worth it. took about an hour from start to finish. you have to slightly modify the stock bracket to clearnence the larger housing. just notch out a little bit of the stock bracket is all. about 25 dollars in additional supplies to get the job done.

FordMustangXBA

I recently upgraded to a Powermaster 140 amp alternator and I'm still having charging issues when driving at night with lights, music, and heat. It's getting pretty irritating, considering I was sure a 140 would be plenty.

FivePointOhh

140 is plenty. you're having grounding issues.

Timspony

140 amp should do the trick! ...a lot of boom boom?

FordMustangXBA

It's a 1200 watt amp and 2 10s, so I dunno. The alternator is a 1-wire rig. What should I check? The ground for my amp and such? I'm not too good with electrical stuff, so forgive me for my ignorance.

enix187

that is a lot of amp power, check grounds, if you didn't rub away the paint for the amp grounds do that. Check you battery cables for corrosion, if all esle fails get a capacitor for you sound system, about 100$ for a qaulity one, and btw follow the install instructions for it to the T, ruined my first one and had to buy a second.

FordMustangXBA

Thanks for the help. What size cap would you recommend? They have 2 and 3 farad at the store nearby me. PS sorry for the thread jack.

FivePointOhh

you dont need a cap. my old mustang was a '98 had a cl1600 watt peak with a max X L7. there is no need for a cap.

all i did was upgrade the grounds under the hood all to 1awg(battery to ground, alt to ground, engine to ground.) and all my power wire and ground wire were 0/1awg. you are having ground issue. i suggest either upgrding or cleaning your connections.