Dash Intermittent while driving - ZR-1 Net Registry Forums

KPW · 09-24-2017

Tach is acting screwy (jumping high quickly) and a few times on a 45 minute drive today the whole dash flashed out for a second and caused a miss. Little worried about it dying on the way home.

Any ideas what this could be? Hot day today...

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karlaw · 09-24-2017

My no start car does something similar. I put new fuel pumps in, which the secondary was completely dead. My key switch still does not activate the starter, the starter is fine shape. So I hook up VATS bypass, turn key to run position, then jumpstart to purple wire, the car immediately starts to fire and barely runs for 4-5 seconds, then dies. Have to wait 10 minutes to retry.
Anyways, my speedo cluster goes crazy, and there is a bunch of clicking noises from glove box area at same time cluster is crazy. Each time the key is turned to run position, the cluster and glove box area noises do a cycle, then settles down. But car never starts.

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KPW · 09-24-2017

Here's some more info:

Stop #1: parked in the shade for ~90minutes. Door sill hatch release buttons don't function at this point. Center console one does. Did not check door locks. Leave the car parked and go about our business. Start it up to head toward dinner, and it's still acting funny (tach is erratic and wrong, low voltage at stop lights)

Stop #2: Low on gas, so stop to fill up. Put 15.8gal in, and car seems much happier (tach is accurate again, voltage is OK...standard C4 discharging feeling) Thinking maybe gas fixed the issue...but no logic so still skeptical.

Stop #3: Stopped for dinner ~5-10 minutes from Stop #2. Everything seems OK when we come back, and we drive 50minutes toward home with no issues.

Stop #4: Decide to stop for some ice cream as it gets dark. When we come back to the car, I start it up and flip the headlights on. As we start to drive away, I notice the tach flutter again, and the dash blinks out and comes back. We manage to drive the 10 minutes to home, with the dash blinking out and jerking the car a handful of times along the way.

Car is parked at home now, so I'm hoping to do some troubleshooting to figure out what's up with this.

Summary:

Dash goes blank (LCD and Gauges) while driving, jerks the car
Fuel up seems to help for a while...but ultimately no fix
Charging seems OK, radio stayed on throughout everything, battery and alternator are both new within the last 2-3 months.

Any ideas on where to start?

conesare2seconds · 09-25-2017

It sounds as though you are getting a total loss of electrical power when the dash winks off and the car misses. I would start by checking the battery terminal cables and the condition of the power distribution block behind the battery tray and the nearby chassis grounds.

scottskill · 09-25-2017

Do you have a good shop manual to start your troublshooting? If so start with CCM Flow chart troubleshooting.

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Paul Workman · 09-25-2017

Sounds like several circuits are involved, which makes think the common ground issue. Well, easy enough to kill many potential problems (grounding):

There are two major ground point lugs located at the back of the motor, right and left of center, below the MAP (see FSM for exact location). Clean them both with a wire brush or sand paper, and then coat the lugs with dielectric grease.

Once that is eliminated, we'll see what else remains...

Just my 2 cents

P.S. Just to add, IF it were just the dash, I'd be thinking about that multi-pin connector at the back of the instrument cluster. (My cluster was flickering and the tach would jump around. That connector was "frosted" (oxidized), but some brushing and electrical circuit cleaner solved that issue.

Ccmano · 09-26-2017

Start with the simple stuff. What is the condition of the battery? These cars are very touchy about low battery voltage. You could have a battery that is just starting to short out. Do a battery capacity test. What is the voltage of the battery at rest and running?
H

WARP TEN · 09-26-2017

Quote:

Originally Posted by Ccmano

Start with the simple stuff. What is the condition of the battery? These cars are very touchy about low battery voltage. You could have a battery that is just starting to short out. Do a battery capacity test. What is the voltage of the battery at rest and running?
H

I agree on this. It is surprising how frequently a large number of electrical gremlins in ZR-1s come back to a bad battery. Then as Dom points out, grounding points are worth a look. Good Luck!--Bob

Ccmano · 09-26-2017

I just had one do almost exactly this. One day, started and ran normally, next day, no start, gauges going wild, alarm going wonky. Turned out battery was shorting. Voltage was low. Replaced the battery and has been perfect since.
H

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lfalzarano · 09-26-2017

Good article on chasing ghost problems
http://m.cloreinfo.com/?task=get&url...tent-faults%2F

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09-25-2017	#5
scottskill Join Date: Aug 2014 Location: Maple Park, Il. Posts: 54	Re: Dash Intermittent while driving Do you have a good shop manual to start your troublshooting? If so start with CCM Flow chart troubleshooting. Sent from my SM-G955U using ZR-1 Net Registry mobile app

09-25-2017	#6
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Dash Intermittent while driving Sounds like several circuits are involved, which makes think the common ground issue. Well, easy enough to kill many potential problems (grounding): There are two major ground point lugs located at the back of the motor, right and left of center, below the MAP (see FSM for exact location). Clean them both with a wire brush or sand paper, and then coat the lugs with dielectric grease. Once that is eliminated, we'll see what else remains... Just my 2 cents P.S. Just to add, IF it were just the dash, I'd be thinking about that multi-pin connector at the back of the instrument cluster. (My cluster was flickering and the tach would jump around. That connector was "frosted" (oxidized), but some brushing and electrical circuit cleaner solved that issue. __________________ Good carz, good food, good friendz = the best of timez! 90 #1202 "FBI" top end ported & relieved Cam timing by "Pete the Greek" Sans secondaries Chip & dyno tuning by Haibeck Automotive SW headers, X-pipe, MF muffs Former Secretary, ZR-1 Net Registry Last edited by Paul Workman; 09-25-2017 at 10:33 AM.

09-26-2017	#7
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Dash Intermittent while driving Start with the simple stuff. What is the condition of the battery? These cars are very touchy about low battery voltage. You could have a battery that is just starting to short out. Do a battery capacity test. What is the voltage of the battery at rest and running? H __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

09-26-2017	#9
Ccmano Join Date: Jun 2006 Location: Sparks, NV Posts: 2,852	Re: Dash Intermittent while driving I just had one do almost exactly this. One day, started and ran normally, next day, no start, gauges going wild, alarm going wonky. Turned out battery was shorting. Voltage was low. Replaced the battery and has been perfect since. H Sent from my iPhone using ZR-1 Net Registry __________________ 90'ZR-1 #1461 Red/Black Ported Intake, Degreed Cams, OBX Headers & Exhaust, Fidanza FW, Secondary Delete, Custom tune, C6 GS Wheels. Sold 08 C6 Z51 Crystal Red Metallic Sold Vararam Intake, Tune, Sold 05 C6 Z51 Red/Black Sold 90'ZR-1 #1723 Black/Gray Sold but not forgotten 91' Z51 L98 White Vert. My First, you always remember your first. Sold.

09-26-2017	#10
lfalzarano Join Date: Feb 2011 Location: Clayton, North Carolina Posts: 1,133	Re: Dash Intermittent while driving Good article on chasing ghost problems http://m.cloreinfo.com/?task=get&url...tent-faults%2F Sent from my iPhone using ZR-1 Net Registry __________________ Lou[COLOR="Red"][B][SIZE="4"][/SIZE][/B][/COLOR]

09-24-2017	#1
KPW Join Date: Jul 2015 Location: Ypsilanti, MI Posts: 116	Dash Intermittent while driving Tach is acting screwy (jumping high quickly) and a few times on a 45 minute drive today the whole dash flashed out for a second and caused a miss. Little worried about it dying on the way home. Any ideas what this could be? Hot day today... Sent from my iPhone using ZR-1 Net Registry __________________ 1991 ZR-1 #1438 Black/Black & Red

09-24-2017	#2
karlaw Join Date: Jun 2008 Location: Alberta Posts: 85	Re: Dash Intermittent while driving My no start car does something similar. I put new fuel pumps in, which the secondary was completely dead. My key switch still does not activate the starter, the starter is fine shape. So I hook up VATS bypass, turn key to run position, then jumpstart to purple wire, the car immediately starts to fire and barely runs for 4-5 seconds, then dies. Have to wait 10 minutes to retry. Anyways, my speedo cluster goes crazy, and there is a bunch of clicking noises from glove box area at same time cluster is crazy. Each time the key is turned to run position, the cluster and glove box area noises do a cycle, then settles down. But car never starts. Sent from my iPhone using ZR-1 Net Registry __________________ LT5

09-25-2017	#4
conesare2seconds Join Date: Jul 2016 Location: Greater St. Louis Posts: 484	Re: Dash Intermittent while driving It sounds as though you are getting a total loss of electrical power when the dash winks off and the car misses. I would start by checking the battery terminal cables and the condition of the power distribution block behind the battery tray and the nearby chassis grounds.