Remanufatured Alternator Readings - Need Input!

[Alan in AZ]

Originally Posted by MPDano

I'll re-check my belt again but i made sure I only had flex the same thickness of the belt. 3/4 inch flex?

Also, I will run the numbers again but at the front post.

Thanks for the reply Alan!

3/4" movement is WAY too much.

Alan

[MPDano]

Maybe I am on crack. I will shoot a quick vid of the flex. I'm afraid to go tighter and start damaging bearings.

[MPDano]

Spoke to the seller and he has a 120 amp that I can trade out with (pay difference). I'm gonna go with this. Will post more readings when i get the 120 amp installed.

[MPDano]

Hello all! Sorry I haven't posted more on this topic when i put in my 120 Amp alternator in. I still get light dimming and I can see my volt drop to under 10 in my stock Volt Gauge upon low rpm's. I did all the 14 pin and Post cleanup and still the same. I am really kicking myself for not just doing the Delco Swap in the first place.

When I was cleaning the 14 Pin, I did notice the wire that goes to the Alternator (exciter?) and it had a little greenish tinge to it. Would it make a difference if I just ran another wire straight from the 14 Pin to my Alternator?

[Alan in AZ]

No - your alternator is starting up OK. I think you just have belt slip at idle.

Alternator belts need to be super tight. Take it to a shop - they will know how tight to crank it.

Alan

[MPDano]

Originally Posted by Alan in AZ

No - your alternator is starting up OK. I think you just have belt slip at idle.

Alternator belts need to be super tight. Take it to a shop - they will know how tight to crank it.

Alan

Thanks Alan for the reply. I will try and tighten it up again. Is there some sort of way to gauge the proper tightness?

[harborman]

Originally Posted by MPDano

Thanks Alan for the reply. I will try and tighten it up again. Is there some sort of way to gauge the proper tightness?

Leo,

According to the shop manual, the belts should (flex) give 10mm at center between pulleys.

[jim ross]

Originally Posted by MPDano

Hey guys,

I finally got around to replacing my tired Alternator (was on car when bought and have no history).

I ended up buying a Stock 90 Amp Remanufactured Alternator and took readings before and after.

I also drove the car in to work today and still have that "in gear" dimming of Instrument Lights until RPM's brought back up. This can't be right. It's a pretty new Battery from earlier this year from Autozone.

Old Alternator:

Car Off: 12.59 Volts
Fast Idle (warm up): 14.20 Volts

New Alternator:

Fast Idle (Warm up): 13.64 Volts
Low Idle (Car warmed up): 13.30 Volts
Low Idle, Lights on: 12.81 Volts
Low Idle, A/C on, Stereo on: 12.67 Volts

Do readings seem correct? Or do they seem low? Thoughts?

Hi MPDANO...i went through 2 reman 90 amp bosches , and one 140 amp new bosch, always weak! i ended up putting on a 200 amp delco 1 wire alt. never a problem again. idles at 14+amps and drives at 13+ even w/ lights and stereo on. best ALT ive ever bought..cheap too!

[Alan in AZ]

BTW if it has been slipping for a while the belt will be in poor shape - the inside surface will get glazed from the friction and will slip more than a new belt would.. You may be able to feel this... It will be getting hot at idle also.

Alan

[MPDano]

Thanks Jim and Alan. I will first check the belt and get it to specs. Also, will check the belt condition. If all those fail, it's Delco swap time. Much appreciated for the info.

[Maleficio]

I have the EXACT same symptoms in my 82, along with an intermittent tach and bouncy oil pressure needle.

I'm wondering if my light dimmer switch under the dash on the left has high resistance in it? I'll bet it does. Dimmer switches never last. Maybe I'll over-ride it because the lighting is so weak anyway.

[MPDano]

Originally Posted by Maleficio

I have the EXACT same symptoms in my 82, along with an intermittent tach and bouncy oil pressure needle.

I'm wondering if my light dimmer switch under the dash on the left has high resistance in it? I'll bet it does. Dimmer switches never last. Maybe I'll over-ride it because the lighting is so weak anyway.

The easiest way to fix all that jumpy stuff is to replace the PCB (Printed Circuit Board) on the back of your Instrument Panel. Also, just jump that dimmer with 2 spades and a wire. If I have daylight when I get home and it's not raining, I will tighten the Alt Belt and see if that helps. I will report back either way.

[Maleficio]

Originally Posted by MPDano

The easiest way to fix all that jumpy stuff is to replace the PCB (Printed Circuit Board) on the back of your Instrument Panel. Also, just jump that dimmer with 2 spades and a wire. If I have daylight when I get home and it's not raining, I will tighten the Alt Belt and see if that helps. I will report back either way.

Have you already over-ridden your dimmer switch?

Is it a huge pain in the butt to remove the pod?

[MPDano]

Originally Posted by Maleficio

Have you already over-ridden your dimmer switch?

Is it a huge pain in the butt to remove the pod?

Not hard to remove your Pod, especially when you remove it as much as I do. My 81, it's all the plates underneath the steering wheel and behind it. Those are held by Phillips Screws. Steering Wheel and Signal Stalk comes off. Then 2 10mm long bolts hold the Pod. When you start lifting it out, be very careful of the 2 main plugs as where they plug into is very brittle plastic. I am sure if you search on my username and pod, I have mega pics of me doing it.

Yes, I don't use my dimmer. The wires are plugged together.

Here's a link to a lot of pics when I changed out my PCB and put some reflective foil to reflect the lights better.

http://porsche928forums.com/viewtopic.php?f=9&t=4&st=0&sk=t&sd=a&start=520

[Maleficio]

Originally Posted by MPDano

Not hard to remove your Pod, especially when you remove it as much as I do. My 81, it's all the plates underneath the steering wheel and behind it. Those are held by Phillips Screws. Steering Wheel and Signal Stalk comes off. Then 2 10mm long bolts hold the Pod. When you start lifting it out, be very careful of the 2 main plugs as where they plug into is very brittle plastic. I am sure if you search on my username and pod, I have mega pics of me doing it.

Yes, I don't use my dimmer. The wires are plugged together.

Here's a link to a lot of pics when I changed out my PCB and put some reflective foil to reflect the lights better.

Porsche 928 Forums dot com - View topic - Pics of my First 928 and Current Project

Awesome. Thanks.

[bwmac]

Great Pics

[MPDano]

FYI, tightened my belt last night and same issue this morning. Looks like Delco Swap out. I plan to do some stuff that will require more electrical power so I can't have this. More to come.

[Maleficio]

I want one of those high output alts, too. Where from?

[MPDano]

Originally Posted by Maleficio

I want one of those high output alts, too. Where from?

eBay is where I got mine. Obviously not working very well. Why would you follow my grief. My suggestion is don't do it, unless you want to buy mine I'm going to Delco Swap it.

[bwmac]

Delco is the company that builds electronics for General Motors. You can go to any auto parts store (with your Bosh Alt.) and tell them you want a chev alt with the same mounting placement in 100 amps or more. they will more then likely sell you a standard 110 amp alt.
I was going to rebuild my bosh but now that i see this thread I will do the swap to the chev Alt.
I have done this to many fords and implement equipment before. They are a good replacement.