84 Fiero Lights Causing Low Voltage (Page 2/3)
Patrick MAR 30, 06:09 PM

quote
Originally posted by maxalator:

I made a video of almost exactly whats happening...



That's weird how the RPMs show to be going up and down exactly in sync (and with absolutely no delay) along with the voltage gauge when the turn signals are on.

The voltage is also shows low for a running engine. Check with a multimeter at the battery while the car is running to get a better picture of what's going on.

[This message has been edited by Patrick (edited 03-30-2022).]

maxalator MAR 30, 06:44 PM
The voltage being around 13 is pretty normal it seems as other 84s seem to hover around there. The battery is new after the one the previous owner put in sprung a leak so I've already ruled out the battery being a part of the issue. I've been doing some looking and cleaning but no dice so I'm going to take apart the steering column as my father has advised to since he seems to think I might be able to find the fix under there.

[This message has been edited by maxalator (edited 03-30-2022).]

Patrick MAR 30, 07:18 PM

quote
Originally posted by maxalator:

The voltage being around 13 is pretty normal...



The voltage gauge in your video is displaying more like 11.5v.

Before you start ripping your steering column apart... does your 4-way flasher also produce the same symptoms? If so, maybe leave the steering column alone.
maxalator MAR 30, 07:36 PM
Yeah the hazards cause the same issue but its even worse than the blinkers. I'm not even going to attempt to make a video of it because I feel I could damage something. The voltage gauge almost always reads right around 13 even when running a bunch of things at once. Its reading at the 11.5 mark because I hit the blinker and it was causing my draining issue

[This message has been edited by maxalator (edited 03-30-2022).]

theogre MAR 30, 08:53 PM
You "Claim" is only HL bulbs and Turn light cause this is Wrong.
Dash gauge reading 13v w/ engine running is Low Volts and is Not Normal even for 84 Fiero.
Tack bouncing is common because used same power and ground in the dash as volt gauge and more.

Even if a dash gauge reads wrong... You can't trust them to find the problem.
Use a real meter on Battery, alt output, and other places.
Should see ~ 12.6-13 engine off w/ full charge battery, 14.5-15 engine running.

Engine and body has many "ground" bolted/screwed to them, between frame and engine, and more in engine bay, in cabin, in front of car.
Not all "Grounds" are power grounds but return lines like for ignition and "one wire" O2 sensor.
1 large ground between engine and frame carries major Alt Ground and often have problems or is gone.

Iffy Alt Sense wiring can do similar as bad grounds or cause high volts.
Alt Output Goes Thru 84 Fiero C500 in a round about way and crap connection there can Burn Down your car.

Link A and C500 E4 runs Most of the car including the dash, ECM, Engine, AC and Heater, other Lights like the turn and brake lights.
Only HL Bulbs and Motors get power by Link B connected to the starter same way as Link A covering in Alt Sense page.
(Link splice w/ Alt Out says goes to EFI is only Standby Power to save ECM code(s), radio clock and setting.)

read wire service but location(s) of whatever maybe different or don't have for 84.
If you can't find 84 data elsewhere... go to alldatadiy.com to get Correct Data For 84 Fiero. They have Same Data as GM FSM unlike crap Haynes and others.

If someone have "modified" the wiring... you likely still need same to find just what they did and is it safe.

Once you find this problem... Continue cleaning/fixed grounds. Crap grounds often cause Dim HL bulbs and more problems.


quote
Originally posted by olejoedad:
The 84 doesn't use a Battery Junction Terminal.

Yup. Some people can't be bother most 84 Fiero wiring is different then later years.
Like Has the Same problems in other GM vehicles w/ fusible links to the starter causing problems and alt output and others going thru C100 that = to C500 in 84 Fiero. The links and ends mounted so low often get dirty/rusty, cooked by exhaust, and worse. 84 Fiero, V6 and V8 front engine vehicles have exhaust running near them and Road salt etc can eat them.

These need same cleaning as grounds above. If ends or links are "bad" then must Replace Them right or expect more problems.
maxalator MAR 31, 11:47 AM
The dash gauge does in fact read wrong and the actual voltage from the alternator and battery is reading correct on a multimeter. In my video the tach is bouncing at the exact same time as the voltage gauge due to the motor struggling with the voltage changing. If I was driving the car and hit the turn signal I wouldn't be able to accelerate due to the turn signal draining all of the voltage. I tested it with the hazards and the cars voltage drops down intensely and struggles to keep the idle at even 600.
maxalator MAR 31, 12:53 PM
Alright so the headlights aren't doing it anymore but the blinkers/flashers are still doing the same thing in the video. I think when I messed with the instrument cluster back in winter I might have rubbed something wrong or left something loose and now its effecting the entire car. I've went through and checked everything else I could find in diagrams and from your comments and now I've realized its probably been with what I did all along. I'm going to take apart the instrument cluster area again today and will clean it up and make sure everything looks satisfactory and hope it fixes it.
theogre MAR 31, 06:38 PM
You took dash out/apart?

Big plugs on back often have problem were hits copper on back board. the "glue" fails allowing the copper to bend/break that can short out whatever the "pin" connected too.

HL Switch can have problems it's own.

But Those should Not cause the main problem(s) that's killing the engine.
Iffy Grounds and Fusible Links may have enough Volts and Amps at one test point and barf in other sections of car.

Pull out cig lighter and test volts there and leave meter connected while try turn lights etc engine off and on.

If mostly/only happens while driving... Check motor/trans mounts and done bone. Crap mounts let engine to move way over spec that often pulls/pinches wires, hoses including vac hoses, etc. Can loosen or break exhaust and intake parts too.

[This message has been edited by theogre (edited 03-31-2022).]

maxalator MAR 31, 06:48 PM
I got my headlights fixed but the blinkers still cause the same issue and now I can get it to happen when only the accessories are on. All the gauges bounce when the blinkers are on and I think something is shorting under the dash or around the steering column. I'm not exactly sure what the problem is but I'm going to take it all apart to clean everything and slide it back together hoping for the best.
WalkerTexan MAR 31, 10:25 PM

quote
Originally posted by olejoedad:

The 84 doesn't use a Battery Junction Terminal.

Battery power is pulled off of the starter lug.



Good point. I forgot that.