All interior lights seem to be pulsating at idle, does anyone have any ideas, the bea - ZR-1 Net Registry Forums

lakemeadzmonster · 07-06-2016

Charcoal Metallic #1217 1467859558101.jpg1990 ZR-1

Sent from my SM-G860P using ZR-1 Net Registry mobile app

Kevin · 07-07-2016

Alternator is going bad

G8nightman · 07-07-2016

Make sure your negative connection to the Batt is clean and tight.

George Maz · 07-07-2016

Same issue here.
More so with dashboard lights diming and brightening. The volts gauge needle floats up & down, especially noticeable at idle...and when using turn signal. Sometimes gauge reads lower than halfway point. Engine idle is smooth at 975-1000rpm (guestimated). I haven't checked connections with a voltmeter yet. Car starts up quickly. Alternator appears newer, clean ...which means nothing since even new ones can be faulty.
relocated Odyssey PC925 battery.
SGC stage 1 cams
corrected alternator pulley size
battery quick-disconnect
some interior LED white lights

Billy Mild · 07-07-2016

I have this issue too. I chalk it up to a battery issue. I have already cleaned all my grounds.

KJL · 07-09-2016

If all connections are tight, it is likely an alternator issue and likely the voltage regulator. Look around and see if there are any folks out there that can rebuild it for you. I had some issue about a year ago and even replaced the alternator and it was then I found the red hot wire on the rear of the alternator was loose. Because of fitment issues I put the old one back in and was back in business. My dash lights still pulsate a little but everything appears to run fine now. Summit sells an alternator that is billed as direct fit but it needs to be dissembled and re-Clocked to get the harness connection where it needs to be. There are other differences as well regarding the upper mounting, ours use a pass through bolt while this unit used two threaded bolts which would not work. The alternator housing needed to be drilled out to remove threads to so bolt could pass through.... I think the brand was Master?

If is just a little pulsation, keep an eye it if all else checks out OK. Replacing the alternator is a PITA. It can be done without removing the intake plenum but other stuff will need to be removed....

07-07-2016	#2
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,624	Re: All interior lights seem to be pulsating at idle, does anyone have any ideas, the Alternator is going bad __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

07-07-2016	#3
G8nightman Join Date: Dec 2007 Location: NYC Posts: 1,192	Re: All interior lights seem to be pulsating at idle, does anyone have any ideas, the Make sure your negative connection to the Batt is clean and tight. __________________ 90 Chevy ZR1 LPE #2315 'SOLD' 90 Chevy ZR1 LPE #2774 'SOLD' 91 Chevy ZR1 Callaway aerobody 91 Chevy ZR1 #1512 91 Chevy ZR1 #951 95 Chevy ZR1 #338 'SOLD' 91 BMW 850i 94 BMW 850csi 95 BMW 850csi 94 Lotus Esprit S4 07 Benz CLS550 06 BMW M5 "SOLD"

07-07-2016	#4
George Maz Join Date: Dec 2014 Location: Long Island, NY Posts: 293	Re: All interior lights seem to be pulsating at idle, does anyone have any ideas, the Same issue here. More so with dashboard lights diming and brightening. The volts gauge needle floats up & down, especially noticeable at idle...and when using turn signal. Sometimes gauge reads lower than halfway point. Engine idle is smooth at 975-1000rpm (guestimated). I haven't checked connections with a voltmeter yet. Car starts up quickly. Alternator appears newer, clean ...which means nothing since even new ones can be faulty. relocated Odyssey PC925 battery. SGC stage 1 cams corrected alternator pulley size battery quick-disconnect some interior LED white lights

07-07-2016	#5
Billy Mild Join Date: Aug 2014 Location: Kansas City, MO Posts: 835	Re: All interior lights seem to be pulsating at idle, does anyone have any ideas, the I have this issue too. I chalk it up to a battery issue. I have already cleaned all my grounds.

07-09-2016	#6
KJL Join Date: Mar 2013 Location: Roswell, GA Posts: 234	Re: All interior lights seem to be pulsating at idle, does anyone have any ideas, the If all connections are tight, it is likely an alternator issue and likely the voltage regulator. Look around and see if there are any folks out there that can rebuild it for you. I had some issue about a year ago and even replaced the alternator and it was then I found the red hot wire on the rear of the alternator was loose. Because of fitment issues I put the old one back in and was back in business. My dash lights still pulsate a little but everything appears to run fine now. Summit sells an alternator that is billed as direct fit but it needs to be dissembled and re-Clocked to get the harness connection where it needs to be. There are other differences as well regarding the upper mounting, ours use a pass through bolt while this unit used two threaded bolts which would not work. The alternator housing needed to be drilled out to remove threads to so bolt could pass through.... I think the brand was Master? If is just a little pulsation, keep an eye it if all else checks out OK. Replacing the alternator is a PITA. It can be done without removing the intake plenum but other stuff will need to be removed.... __________________ 1995 ZR1 #159 Ported,Corsa,4.10 Rear, Dual Disc RAM Clutch, Alum Flywheel, Haibeck Chip, ZFDoc Plates, Relocated Battery 400 rwhp 1992 ZR1 #280 Ported, Locked Secondary's, Flowmaster Exhaust, Haibeck Chip, 375rwhp 1996 Collectors LT4 (Stock) 1972 Convertible 434 Small Block 572 rwhp

07-06-2016	#1
lakemeadzmonster Join Date: Nov 2006 Location: Las Vegas, Nevada Posts: 137	All interior lights seem to be pulsating at idle, does anyone have any ideas, the bea Charcoal Metallic #1217 1467859558101.jpg1990 ZR-1 Sent from my SM-G860P using ZR-1 Net Registry mobile app Last edited by lakemeadzmonster; 07-06-2016 at 10:53 PM. Reason: The beast is running better than ever hate to touch anything, not sure what happened to my original post, some of it came up missing