I've decided I need to upgrade my alternator. I've got a few things extra on this car so I'm looking into going with more power. It is a '95 with the 6 speed. I looked at SUMMIT and the cheapest is a 200 amp for $270. That's pricey and the amps seems too high. What are my other options? Is there a 180 amp around somewhere?

 

You do realize that the thing doesn't charge at the "200 amps" all the time...right? It only charges at the amps required by the system.

 

Unless you can actually substantiate the need it seems certainly a waste of money. If your current is OE/GM original I'd maybe consider refreshing it at a "LOCAL" shop. A '95 is a 140AMP CS144 and should do anything your system requires if in good condition. There's options to do a CS144 to 170AMP with a dual bridge rectifier. I've done those for some commercial fleets that had a demand. Haven't done one in maybe 10 or so years but they were very reliable. There's 170AMP options I believe in a single also.

Look at some of the CS144 options from these folks. I'm not promoting them but I have bought some parts from them in the past and their service was good.

https://alternatorparts.com/cs144-se...lternator.html

I wouldn't want an "off the shelf" Summit myself. They need to compete in pricing schemes to match the Internet resellers so there's only one way to do that and that's using "OFF SHORE" vendors.

Your location may limit what's readily available but if there's a shop that does the builds for the local LEO fleet, municipalities, state DOH etc I'd certainly prefer/suggest a build of what you've got.

Tom has a very good point and you do realize there's wiring that you need to do also to make the charging system efficient.

 

Ok. Even for a jump to 170 would I have to do the same modifications as I would to say a 200? I need a higher one yes. The 140 is testing good from 2 different testers and it's not keeping up with the car's demand. The extra things it has in it are an electric water pump (6.1 amp draw), bigger/better sound system with amp, backup camera but i don't think that's enough of a draw to matter, and the engine has been rebuilt with probably a hint more compression. With the ac on and headlights, the volt meter on the dash always displays under 14v. I think even without the headlights it does this. Soo even in the off chance a oem 140 helps a little, I dont want to take the chance. By the way I looked up an alternator shop and it looks like one near me deals with alternator repairs so I can give them a call Monday.

 

For an alternator to "keep up" you need to have efficient wiring, a good battery and of course quality alternator. An OE 140AMP wired correctly and maybe with an "over-drive" (smaller pulley) to spin the alternator faster at idle/low RPM might do very well. Most of the higher AMP units require the same "over-drive" to charge at idle/low RPM. They don't maybe mention it but when you "fuss" about performance it's likely what they'll tell you to do and they'll expect you to do it on "your dime" and time.

I ain't going to suggest cable size because that can get very argumentative and actually maybe some of what I've already mentioned could be argued. SO ...

Is your current alternator the OE? It would have the information either etched or stamped in the case. An OE/GM for '95 might be a # 10480202. Get what ever information there is on the case and post it.

I would think a reasonable approach to your particular situation is "rewire" it with cables that are new (including battery cables), sized appropriately for what's suggested for maybe 170AMP + then evaluate the charging system with something other than your cluster VOLT-METER.

 

So you think if I first start upgrading the wires I might see an improvement? Does that pulley require a new belt?
I don't know what numbers are on his as it looks like the sticker came off. But I've never replaced it.

 

while I wait on your response to what I just posted, I found a couple alternators to add to this equation.
this is a 150 amp
http://www.ebay.com/itm/150-Amp-High...VVnu7U&vxp=mtr

and a 200 amp
http://www.ebay.com/itm/HIGH-AMP-HUM...xTxeeV&vxp=mtr

both very reasonably priced for this application.

 

I can't make out the information on your alternator but you seem he!! bent on buying so maybe the best advice is just pick one and do it. Understand from where you're buying and it's possible ramifications.

If you can make out some of the information maybe post back with it.

One last time - I'd have a the charging system "load tested" by someone that knows what they're doing using the proper "carbon pile" device. Have the system checked at multiple RPMs if by chance that they don't. Lower RPM & idle is the concern. I can't speak for the creditability of a load test done by an auto parts store. The device used and the operator is maybe important.

After you have a "for hire" load test done then determine if a maybe a "local" repair/build of what you've got won't accomplish what you need for less $$$'s and you'll have "a go to" if you have problems.

An internet purchase might get you a go to he!! if you have problems.

I mentioned wiring what you've got but you've got a choice there also. Cheap out with the cable and you might have as well done nothing maybe. 1AWG cable (tinned fine strand Marine grade) would certainly be best for larger AMP and the length.

Pulley diameter change would certainly require the change of the belt. Is the pulley diameter important? Maybe not but might be the fix for a low RPM/idle issue.

If you can determine that yours is in fact maybe an "off the shelf" reman then maybe the buy is the thing to do. I'd do it with a "LOCAL" for sure were it me and I could do it at a comparable cost. Comparable cost and the opportunity for a "toe to toe" conversation if there are issues I'd say is very important.

 

I am not hell bent on buying one of those if it can be done cheaper. You misunderstood.
I will talk to these guys around here to see what they can do and the pricing.
The only problems so far are these wires and the belt. But, I did look up the type. Do you know the length of my positive cable and my ground cables? This is my daily driver so I can't pull all the cables and match them.
Any idea on the belt I would need if I'm going to be changing that too? I don't run the water pump anymore and air pump if it ever had one. I can't see where it would go anyway.

 

The wiring on a later C4 with the under-hood fused/relay control might require some thought. Usually when doing a HI-AMP install there's a MAXI FUSE added in the mix somewhere. How to approach it on a later C4 I don't really know but since the battery goes first to the box you could improve that cable by one/two value, add maybe a MAXI in place of the fusible link then increase that wire to the alternator by a one/two value.

All FSM have crank/charge at 8A-30 so look at your FSM and if you decide to do it maybe get local advice or determine what you feel you'd like to do and get comments from users here.


This is how I might do it, battery to MAXI BLOCK, wire from MAXI to the OE UH #1, and the heavier to the alternator from the MAXI BLOCK on the controlled post. Honestly I've never given it any thought. The belt if you do smaller, you measure yours and reduce the length appropriately and maintain the tensioner operation as intended. Most tensioners have an install/worn indicator that you could use.

You will need to construct the entire positive cable from scratch I'd think for it to be efficient and a performance plus. Is the cable from the starter long enough to cut and reuse? Likely not I'd think.

 

This is getting complicated. I read the FSM page but it's not really doing much to my issue.
You say to run a new maxi fuse inline from battery to starter, but there's already a fuse block there? Also I thought it was the alternator wire I was upgrading. Is the alt. wire still going to be a #1 gauge?
What is UH #1?
How do I even go about locating that belt size?

 

This is not complicated. Locate a competent auto electric shop in your area and make an appointment. Have charging system evaluated at idle and 1500 RPM. At that point you can get their recommendations and report back. Your alternator is the basis of many of the amped up alternators you reference. With a competent shop they should be able to reasonably accommodate your needs. Good Luck!

 

Stick with the factory alternator. Mine is sitting in the parking lot at work with 194K on it. Had a front bearing replaced about a year ago, that's it.

Mike

 

If the bass from the sound system is the main draw and causing problems, you may want to just add a capacitor to the system which you should have anyways if it is that big of a system. If still a problem, then I would move to a 140@. Really no need to upgrade any wiring since the factory portion of the wiring shouldn't be a problem, just the aftermarket stuff.

 

I did my alternator bearings myself a year or so ago. I think I spent ~$24 on the two. They were due, but the brushes were still in great shape.

140 amp * 13.5v =1890 watts. You lose some to resistance, accessories running, etc. but what do you have that's drawing so much power? I have two large amps in my 'Vette for my stereo and they don't pose any issue at all. I really don't think you have a problem that needs fixing. You said earlier in the thread that;

"under 14v"? As in 13.7v, for example? That IS, "keeping up". I would not begin to be concerned until my system volts were under 12.5v or so, w/heavy drawing accessories on, while idling. If you system voltage is higher when running, even w/all your electrical draw going on, than it is when turned off, then that is proof that your alternator is charging and more than meeting the demand that the system is placing on it.