i've search for a solution to my problem and have found a lot of confusing answers.
i'm trying to get some peace of mind and confidence back in my car ('88 Formula).

it all started when the car wouldn't start. i thought it was the starter so i replaced it.
found out it was the battery, so i replace it with one (red top optima) that was in my
other car from Jan. 2004 but was never used. after two days of driving (about 200 miles)
the battery expolded. put in another red-top optima, never noticed this before but the
voltage gauge in the car is reading high.

SYMPTOMS:
when i first start up the car the voltage gauge will go to the last white mark before the
red zone. then after several minutes of driving it will drop a couple of tick marks. also
i notice that the gauge will pulsate when the turn signal is on. another thing it will drop
a little when i step on the brake.

i've taken the car to two different autozones and both of them said the same thing.
(1) check for corrosion on the cables, didn't see any.
(2) said the charging system is working correctly.

i've added a new ground strap, from where the little black wire from the (-) terminal
attaches to the body, it goes from there to the head on the engine. that didn't seem
to change any of the symptons describe above.

i've read that the fluctuation is normal but i've never noticed it before when driving,
so i'm suspicious and don't know what else to check for.

the car has gotten me so paranoid that i'm afraid to drive it, help me to trust my car again...

thanks,
tom.s

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I've had tons of problems with my electrical system and the latest sounds similar to your problem. When i would drive at high rpms on the interstate the volt gauge would run up to over where it normally sat and would almost be in the red. When I would hit my brakes or turn signals, the voltage would drop and fluctuate. My problem was the plastic connector going into the alternator was gunked up and wasn't making a good connection. After I cleaned that up, the car has run fine with no fluctuations in voltage. I hope this helps, it's easy to try at least.

------------------

1966 Pontiac GTO convertable, tri-power 389
1st owner 84 2M4 SE 4-speed
87 2M4 Automatic

Check the voltage with a REAL voltmeter. Just hook one up to the battery then start the car and it should be around 14 V

quote Originally posted by goatboy: I've had tons of problems with my electrical system and the latest sounds similar to your problem. When i would drive at high rpms on the interstate the volt gauge would run up to over where it normally sat and would almost be in the red. When I would hit my brakes or turn signals, the voltage would drop and fluctuate. My problem was the plastic connector going into the alternator was gunked up and wasn't making a good connection. After I cleaned that up, the car has run fine with no fluctuations in voltage. I hope this helps, it's easy to try at least.

thanks... i'll give that a try.

quote Originally posted by goatboy: I've had tons of problems with my electrical system and the latest sounds similar to your problem. When i would drive at high rpms on the interstate the volt gauge would run up to over where it normally sat and would almost be in the red. When I would hit my brakes or turn signals, the voltage would drop and fluctuate. My problem was the plastic connector going into the alternator was gunked up and wasn't making a good connection. After I cleaned that up, the car has run fine with no fluctuations in voltage. I hope this helps, it's easy to try at least.

i did it and no change.

anything else to try?

thanks,
tom.s

ive got the same problem... it still does it even after i had the alt. replaced and i put in that ground strap that everyone was raving about for a while. im thinking that i need to swap some ground straps.

------------------
'86 Fiero GT

My Fiero XoticRydz
Mid-Rear Madness

quote Originally posted by TaurusThug: ive got the same problem... it still does it even after i had the alt. replaced and i put in that ground strap that everyone was raving about for a while. im thinking that i need to swap some ground straps.

i'm glad i'm not the only one having this problem. hopefully we can figure this thing out or someone smarter than me
will tell me how to fix it.

quote Originally posted by Tom Slick: i've done that and i get 14.# volts. thanks...

If you are getting 14V then what are you still mucking around with this for... the reason it was suggested was to see if the volt meter in the car was off. If you measured 14V while the car is running then it is just the volt meter on the dash... not the charging system... are you trying to fix the volt meter?

I can almost say that its definately a bad voltage regulater in the alternater.If you continue to drive the car like this you can fry the battery again or even fry the ECM in the computer.And dont forget to save your receipt, theres alot of c*r*a*p alternaters out there.It would also be a good idea to make sure you have a heat shield on the alternater,because of the close proximity to the exhaust manifold.

The chargingf system should put out 14 volts when the car is running. Turning on the lights, etc can drop the output when the car is in idle. It is not a bad idea to check all grounds and other wireing to eliminate line loose. I have had two cars that when the engine was at idle, in gear(automatic) at a stop light at night( headlights radio etc) the Amp gauge dropped to 12 volts. I have yet to have a battery blow up. That could have been a bad battery, not the charging circuit.

Frank

If you are still haveing this issue, let me know. By no means am I a expert mechanic but I can get around very well on my own. I also have parts that we can swap out to see if the problem goes away. Drop me a Pm and we can set something up since I am just right up the raod from ya.

[This message has been edited by MstangsBware (edited 10-20-2004).]

quote Originally posted by MstangsBware: If you are still haveing this issue, let me know. By no means am I a expert mechanic but I can get around very well on my own. I also have parts that we can swap out to see if the problem goes away. Drop me a Pm and we can set something up since I am just right up the raod from ya.

thanks...
pm sent.

14.8 charging volts is normal. If the output on the alternator post and the voltage at the battery both read the same voltage, and they should, then the dash guage is bad. Repair could be as simple as removing and re-orienting the guage needle.

JazzMan

[This message has been edited by JazzMan (edited 10-21-2004).]

it sounds like an overvoltage from the altenator. the altenator output specifications may be affected by temperature or load. example, the altenator might read normal when cold and no load, or abnormal when hot & under load. 14.6vdc is the norm. if 14.8vdc is the norm for that altenator then its tolerance might exceed 15vdc when loaded. a properly executed load test on the altenator might not even detect this problem. there is also the possibilty that there is excessive ac ripple from the altenator. this means that ac is actually leaked into the dc system of the fiero.

quote Originally posted by JazzMan: 14.8 charging volts is normal. If the output on the alternator post and the voltage at the battery both ready the same voltage, and they should, then the dash guage is bad. Repair could be as simple as removing and re-orienting the battery. JazzMan

Thanks JazzMan...

is there a way to fix the dash gauge?
so do i need to move the battery to another location?

tom.s

Is your alt. a si or cs alt. I have a early porduction Formula with the si alt. and a late production 88 GT with the cs alt.
May God have mercy on your sole if you have ci alt.

quote Originally posted by alienfiero: Is your alt. a si or cs alt. I have a early porduction Formula with the si alt. and a late production 88 GT with the cs alt. May God have mercy on your sole if you have ci alt.

how do you tell the difference?

thanks,
tom.s

quote Originally posted by Tom Slick: thanks for the info... is there a way to test this? tom.s

With an AC leak you would most likely see the ripple in the lighting at night... do your head lights and dash pulse at night?

A word on ground straps; a lenght of 8 gauge wire does not constitute a great gound. Put something really heavy like jumper cable size and put to it to a clean bolt on the engine and a good clean (no rust) bolt on the body. As for meters bouncing with the directionasl and brake lites, most will.

quote Originally posted by carbon: With an AC leak you would most likely see the ripple in the lighting at night... do your head lights and dash pulse at night?

nope

tom.s

Can I ask again?

If you are getting ~14V with you real voltmeter and you aren't having any electrical problems other than the car's volt meter showing high voltage, why aren't you just looking to fix the volt meter or ignoring the problem? My old 84 oldsmobile cutlass cierra wagon did the same volt jump with the turn signals and brakes. My fiero also does it. If it was really jumping around it would have to be noticable in the intensity of the headlights and dash illumination. I have just come to expect that it is normal. :shrugs:

[This message has been edited by carbon (edited 10-21-2004).]

A cs alt. has a internal fan you should be able to see the fan by looking in to the engine bay down at the alt.
On the top connection there should be 3 wires at the connection one lg. red wire, one brown and white wire and one brown wire.
If it is pulsing replace the alt. immediately!!!

Things to do before removing your alt.

1. Fallow the red wire from the bat. to the buss and then fallow the orange wire to the weather pack connection that is under
some blk. electrical tape. This is your power connection to the ecm. disconnect. Also pull the ecm fuse and the raido fuse.
Disconnect all your engine sensors, map ,iac, tps, vss. Before removing the battory connections!!!

2. Remove the battory connections, neg. first. Then remove the alternator connections.

3. With a cs alt. make sure that your bat. is fully charged before reconneting.

4. When you installt the new alt. connect the bat. and alt. first before reconnecting the ecm power,
ecm and raido fuses and the engine sensor connections.

Doing these steps will go along way in preventing, the nightmare.

quote Originally posted by carbon: Can I ask again? If you are getting ~14V with you real voltmeter and you aren't having any electrical problems other than the car's volt meter showing high voltage, why aren't you just looking to fix the volt meter or ignoring the problem? My old 84 oldsmobile cutlass cierra wagon did the same volt jump with the turn signals and brakes. My fiero also does it. If it was really jumping around it would have to be noticable in the intensity of the headlights and dash illumination. I have just come to expect that it is normal. :shrugs:

sure, ask all you want...

just call me PARANOID, i don't like things that are out of the ordinary.
yeah i know, "welcome to the world of fiero's"
it was not doing this before the starter/battery problem.
if the gauge is action normally then i just want to double, not make triple check everything.
i don't want to make the local traffic news as my fiero blew another battery and caught on fire while driving home.

???: can i take the voltage from the factory volt gauge to see if it's reading correctly

thanks,
tom.s

Thats cool... everyone has their reasons. If you get the pin out for the connector for the aux gauges you can check it there or if you don't have them you can find the pin in the main cluster that is connected to the volt meter. As far as I remember the volt meter is pretty much connected to the battery but I will check the factory service manual when I get home.

edit for stupidity

[This message has been edited by carbon (edited 10-21-2004).]

ok, i need to verify an assumption i have.
1. i check the voltage at the back of the car's volt gauge.
a. with the key turn on (not motor) the both the meter and gauge read the same.
b. with the engine running, the gauge was at the last tic mark before the red zone
but the meter said 14.# volts (good, i hope).
c. with the engine running, i step on the brake pedal and watch the voltage drop
a couple of tenth's volts.
d. same as c but with the turn signals lever, same results.
2. i check the battery voltage and the alternator voltage while the engine was
running and they were within a couple of tenths volts. (good)

now that it looks like the voltages are normal, can i assume that my volt gauge
in the car is at fault? or is there other things i need to check?

thanks,
tom.s

P.S. "+" all round for everyone's help, thank you.

quote Originally posted by Tom Slick: Thanks JazzMan... is there a way to fix the dash gauge? so do i need to move the battery to another location? tom.s

Sorry, brain fart on my part, I edited my post to reflect what I was thinking, not what my fingers were typing.

It should have read "reorient the guage needle".

D'oh!

JazzMan

For a quick and "low budget" fix, remove the bezel and front glass from the aux gauges. Pull the needle (careful, pull at hub and pull straight out) off, turn key on and measure battery voltage with a known accurate meter. Push the needle back on with it pointing to the correct voltage and put the lens and bezel back on.

Over years and miles, vibration and wear can (and does) cause the pointers to slip on the shafts. Almost every Fiero temperature gauge is wrong because the needle slipped, the other gauges are built the same way...