It might be a coincidence, but my Formula's alternator appears to have stopped charging shortly after I had totally removed my dash, gauges, center pod, etc and then reinstalled it all.
I've driven the car several times since then, and the volt meter was showing proper voltage. However, today I started getting noise on the car's radio (going up and down with engine revs) and later on noticed the volt meter was indicating just barely above the red. I knew I was on borrowed time, and drove straight home... and almost made it. The car died half a block from my driveway, with the battery deader than dead. Anyway, I got the car home with another battery.
The Formula, being an '88, has a CS alternator. If I understand correctly, the CS alternator still requires a charge/alternator warning light in order to get "excited" and start charging. I'm aware that some of the warning lights don't work in my dash (such as the seat belt warning light), but I'm not sure if the alternator warning light is located with the rest of the warning lights in the dash... or is the alternator warning light in the accessory center pod with the volt meter?
I should know better... but electrical knowledge has never been my strong suit, so any advice with this is appreciated. I want to obviously check what I can while the alternator is still in the car... before I scrape up all my knuckles to take it out.
[This message has been edited by Patrick (edited 08-11-2020).]
From 88 FSM. Looks like only the Duke has an indicator bulb.
Tony, how or where is it indicated in your diagram that only the Duke has an indicator bulb?
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Originally posted by fierosound:
V6s have the voltage gauge.
Does that necessarily rule out that the indicator bulb might not possibly be located with the voltage gauge in the Rally Gauge Panel (as the diagrams refer to it as)?
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Originally posted by cebix:
This is from the '86 manual and it's there in the cluster. The alternator wiring looks different though.
Yes, the wiring is different as the earlier Fieros have SI alternators, whereas the 88's have a CS alternator.
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Originally posted by cebix:
Maybe you don't need that light.
This is what I'm unsure of. I don't want to be replacing an alternator if it's just because a 5¢ light bulb isn't working.
Light is in the dash. OEM Volt meter has nothing to do w/ turn on the alt.
SI and most CS conversions and some OEM CS need the bulb to work. Think 88 Fiero V6 still needs this. Some CS setups has "Extra" wire to turn on the alt w/ Alt Bulb dead like 87-88 dukes. See my Cave, CS Alternator
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Light is in the dash. OEM Volt meter has nothing to do w/ turn on the alt.
SI and most CS conversions and some OEM CS need the bulb to work. Think 88 Fiero V6 still needs this.
Alright, I'll start poking around the dash/instrument cluster to see why all the warning lights aren't coming on. Thanks Ogre.
One side note to this situation. My Formula was actually pulled out of a forest six years or so ago. Among other things, it was missing its instrument cluster. I have a lot of different Fiero components here, and I installed an instrument cluster from... oh, I dunno... possibly an '86 GT. I wonder if there are some slight variations to these clusters that might be preventing all my warning lights from coming on. Just a thought. I know for a fact that some of the clusters I have here, probably from earlier 4-banger Fieros, the individual warning lights are in different locations within the cluster.
Light is in the dash. OEM Volt meter has nothing to do w/ turn on the alt.
SI and most CS conversions and some OEM CS need the bulb to work. Think 88 Fiero V6 still needs this. Some CS setups has "Extra" wire to turn on the alt w/ Alt Bulb dead like 87-88 dukes. See my Cave, CS Alternator
The following are screen grabs of Ogre's site. Even though my dash warning lights do not include a lit/functioning bulb for the charging system, I still get 12v (with key ON) indicated on both the L and I terminals. Am I correct to assume that the bulb is not then required with my charging system... as if it was, I don't believe the L terminal would've had any power?
I've now pulled the alternator. The problem with these CS alternators is, although they're more efficient than SI alternators, they're not serviceable like the SI alternators are. Instead of paying five bucks to easily replace something like a diode trio, I'll probably have to replace the entire alternator. That kind of sucks.
[This message has been edited by Patrick (edited 08-12-2020).]
After reading over various articles on these alternators, it's finally sunk in that the CS alternator in my Formula is directly related to the alternator in my '87 L4 Fiero... which I'm in the process of stripping down. Yes, it's a CS alternator in the '87 duke. Obviously it's not a direct swap, as the mounting "ears" on the front plate are in different locations than what is required for a V6 installation. However, the back half, which contains the stator and all the electronics (rectifier, regulator, etc) appears to physically be the same. And I know this alternator worked properly when this Fiero was "retired".
So... would there be any reason why I couldn't just take the back half of the alternator from the L4 and transplant it to the V6 alternator? Would there be any compatibility issue between stators and rotors and/or electronics?
While doing my research on these CS alternators, I came across a thread Here by some dork named Patrick from 1999. He had this to say about replacing the alternator in his '87 L4 Fiero...
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Originally posted by Patrick:
I went to a local auto wrecker and got an alternator that must have been rebuilt just before whatever car it was in got cracked up. Really great condition. (The alternator, not the donor car.) Fifty bucks.
Of course, that was me... but it got me wondering... whatever happened to that alternator when I retired the '87 Fiero a couple years later? I still have that Fiero... in pieces. The alternator was not on the engine... but after pulling a bunch of assorted parts out of the trunk, there it was, sitting on the bottom of the trunk for almost 20 years ... the alternator!
So this is the alternator that I took the back half (stator, rectifier, regulator, etc) from and transferred it to the front half (rotor, pulley, etc) of the alternator from my Formula.
Started the car up... charges at 14 point something volts. A rebuilt alternator sourced locally (if they even have the proper one in stock) would've been around $150.
I'm a happy camper.
[This message has been edited by Patrick (edited 08-14-2020).]
Glad that you got it running again. Just wanted to answer your question about where it says in the manual that only the duke uses the charging light. It says it right on the schematic below the charging bulb (L4 VIN R only).
I knew I was on borrowed time, and drove straight home... and almost made it. The car died half a block from my driveway, with the battery deader than dead. Anyway, I got the car home with another battery.
I wonder if there are some slight variations to these clusters that might be preventing all my warning lights from coming on. 
