140 Amp Alternator

[turbo39151]

I pulled the bulb and it's fine. I tend to assume that the circuit board is fine because all of the other lights seem to work just fine.

This Brown wire is the one that plugs to the alt? IF so , how do I test it while it's plugged?

Or am I misunderstanding?

As of this writing I have no alt. Can I still test the battery light that we're talking about? If this is the case, how do I Ground the brown wire? Also, what exactly is the "L" terminal?

Sorry for all of these stupid questions but I'm really not very handy in the electronics dept.

Thanks for the assistance thus far.

 

[David65]

You pulled the alternator light out of the dash and it was ok? Maybe the socket to pc board connection wasn't? You can check the dash alt light by removing the 4 pin plug from the rear of the alt and sticking a wire in the plug (the cavity that the brown wire is in) and touching the other end to the alt case or some other ground. Then turn on the ign switch (don't start the engine) and the dash alt light should come on. If it doesn't, theres an open somewhere in that circuit. Like was said, some have problems where the socket pops into the cluster. The L terminal is called that because it goes to the light. If the alt has a problem, it grounds that terminal and the light comes on so you know.

Btw, I just emailed you a scan of that page out of the shop manual.

Oh, and if it was me, I'd take the booster out for now at least. I think it should connect to the sense (S) terminal on the regulator plug, not the lamp terminal as said in post #19. I've never used one, maybe someone who has can chime in here...

David

 

[turbo39151]

Actually, the volt booster splices into the brown line that plugs to tha bcak of the alt. You cut off the factory plug and splice in the booster plug and then hook up the vacuum line for it...

I'll go and test for the light to come on..

 

[turbo39151]

Ok I went an put a paper clip on the end of the plug and grounded it to the alt tensioner pulley. I turned the ignition to "on" - (not run) and the battery "volt" light did come on...


Now what???

I can't win for losing

 

[TurboDave]

Ok I went an put a paper clip on the end of the plug and grounded it to the alt tensioner pulley. I turned the ignition to "on" - (not run) and the battery "volt" light did come on...


Now what???

I can't win for losing

Get the volt booster out of the circuit!!! They've been proven time and time again to be way more trouble than they're actually worth, and when they go bad, they will take out the alternator with them. I learned this costly lesson after one of them burned up three alternators in a row.
No more gimmick garbage for me!

BTW, why did the new alternator only put out 13.5v on their test??? they should be making something more close to 14.5.

Might be time to look at a different brand. AFTER you remove the volt booster.

 

[turbo39151]

I am victorious!!!!! :biggrin:


Finally! I got a good one. I had wanted to confirm my connections so a local TR buddy loaned my his ALt. (14.5- no problem)

I wanted to test the new one at the store and found out their tested was broken....

Anyway, installed new unit and I have 14.5-14.7 at idle. Yippee.
I haven't removed the volt booster yet but will probably do so shortly.

Anyway, here's the pertinent info for anyone who's looking to do this upgrade and needs part numbers:

I used Napa (they were the cheapest)

Alternator- Reman unit - Part#66173 the other one I had tried to use (twice) was Part#8112-5 (Unit was for 95/96 Impala SS 140 Amp) $136.99 + $87.00 core LIFETIME WARRANTY!! -Napa-

New Belt- 13/16" x 63-5/8" Part# 060630 $24.09 -Napa-

New 2 gauge wire from battery to starter and for ground $3.00 per foot (6 ft)
New 4 gauge wire from battery to alt (can't remember price or length) cheap
-Napa-

Sidepost battery adapters (to be able to use top mount post ends) $1.99 each -Ace Hardware-

Platinum Battery terminals (0,4, 8 gauge) (both + & -) $18.49 shipped -ebay-

Battery cut-off switch $2.99 -Harbor Freight- (very convenient!!!)

Miscellaneous copper ends and heat shrink $5.00 or so -Ace Hardware-

Also want to thank everyone who helped me try and troubleshoot this bad alternator dilemma especially DAVID65. Thanks again....

 

[5ltretr]

Sorry to ask again, but was the impala alt the problem????

 

[turbo39151]

The first two alts were bad right out of the box. The 3rd one, also an Impala alt was just fine.

Oh and btw, everything fit like stock, no clocking issues...

 

[mikec1969]

I have always had the best luck removing the original alternator and having it rebuilt at a local shop. It costs $35-$50 you get your unit back (keeping the numbers correct- if you care!) case restored, new internals and he upgrades the output. I can't tell you how many times I've chased bad alternators from auto part stores.