86 lights surging
Thread Starter
Intermediate
Joined: Apr 2003
Posts: 25
Likes: 0
From: Lyndon Sta. WI
86 lights surging
Lights on entire car were "surging" for a number of miles/days. Engine RPM didn't seem to change the frequency. Not bad enough to be bothersome but wonder what is starting to fail? Just installed a hypertech chip, took the car out for some high speed runs. Seems to have settled down the surging lights but I think only for short time. Any thoughts?
:auto:
:auto:
Team Owner
Joined: Sep 2001
Posts: 62,139
Likes: 1,727
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: 86 lights surging (bikerski)
The Chip doesnt affect the lights
If they are surging, your alternator is likely going out. Usually its the voltage regulator or something inside.
Might as well replace the whole thing.
If they are surging, your alternator is likely going out. Usually its the voltage regulator or something inside.
Might as well replace the whole thing.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: 86 lights surging (bikerski)
If your lights are pulsing, your alternator's voltage regulator is oscillating. Look at the waveform across the battery with an oscilloscope. Most ignition analyzers have this function to determine if one or more diodes aren't working, but they will also show if you have an oscillating (sinewave) waveform out of the alternator. You can replace the regulator , or the whole alternator. Watch the lights when you unplug the alternator, if the pulsing quits, it definetely is the alternator.
Instructor
Joined: Apr 2003
Posts: 112
Likes: 0
From: Front Royal VA
Re: 86 lights surging (bikerski)
Check your electrical connections at the battery. If they are tight & have no build up, go for the alternator. Similar problem on mine was cured last year with a wrench by tightening the + side of the battery.
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Re: 86 lights surging (bikerski)
Interesting, let me know what works.....
I have a similar problem of when I start slowly in first gear the lights seem to surge... I wonder if that means the alternator is going too...
Let us know the cure that solves it and good luck!
I have a similar problem of when I start slowly in first gear the lights seem to surge... I wonder if that means the alternator is going too...
Let us know the cure that solves it and good luck!
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Re: 86 lights surging (USAsOnlyWay)
USA, if you drag the rpm down on your slow 1st gear startups, the alternator will not turn fast enough to keep up with the electrical load and the battery will supply power to your electrical system which makes the system voltage fall from 14 down to 12, then when you get underway, your rpm rises and the alternator will be turning fast enough to supply 14 volts again and is the reason you observe a momentary dimming. (How's this for a runon sentence?)
Le Mans Master
Joined: Dec 2002
Posts: 5,270
Likes: 3
From: Seattle Area WA
Re: 86 lights surging (jfb)
Jfb, thanks. Good good I was planning a trip to the coast soon and I didn't want to have to pack an alternator in the emergency road pack. Thanks, and sorry to hijack the thread.....
Found that problem yet? :flag
Found that problem yet? :flag
