Busted tach - ZR-1 Net Registry Forums

efnfast · 04-03-2012

Went for a ride today, and no tach, either that or the wind was puhing me very fast. What makes the tach not work? 1990, no trouble lights.

Paul Workman · 04-03-2012

Quote:

Originally Posted by efnfast

Went for a ride today, and no tach, either that or the wind was puhing me very fast. What makes the tach not work? 1990, no trouble lights.

What was it doing? Reading too high, pegged high, registering ZERO, what?

P.

efnfast · 04-03-2012

Paul, it sits right on zero, never moves. Did it once the other day, than seemed alright. I've restarted a couple times with no change.

Steve

GOLDCYLON · 04-03-2012

Quote:

Originally Posted by efnfast

Paul, it sits right on zero, never moves. Did it once the other day, than seemed alright. I've restarted a couple times with no change.

Steve

Could be anything from a bad cap or resistor on the back side to a mouse chewed cable in the harness. I mention this as you say you dont drive it much.

Seeing no obvious rodent or harness damage I suggest pulling the gauges and cleaning the back side contacts with electronic contact cleaner.

While you are there make a project out of it and replace the 20 plus year old bulbs. Make a call on your instrument panel lens if its scratched etc. Great time to get this ALL done in one.

You will need to drop the steering wheel a bit in order to get the gauge lens surround off in order to access the backside of the IP

efnfast · 04-03-2012

Oh great, this sounds like a dandy. Must be a winter project. Spring is here, I'm not going to disable it now. Are the bulbs stock items at the chevy dealer?
Thanks GC.

VetteMed · 04-03-2012

The bulbs are available at rockauto.com

I think the PN is PC161. It's a 194 bulb soldered into a plastic base with contacts for the printed circuit board.

Paul Workman · 04-04-2012

Actually, the cluster is only about 30 min to an hour to get it out, and same to reinstal it. Add to that whatever R&R'ing to be done, and that's it.

BTW, Zip has bulbs for $5.00 ea., ASSUMING you need to pull the cluster (which has not been established yet).

P.

efnfast · 04-04-2012

Thanks Paul, so how do we determine that the cluster needs to be pulled?
GC had mentioned mice, never seen any signs. I hope not, they can make a mess.
Steve

GOLDCYLON · 04-04-2012

Steve this is part of the troubleshooting process. The pulling of the cluster and using the electrical contact cleaner is the first of many non invasive things to do. The worst case scenario is that the cluster may have do go out for a service.

After cleaning you can verify if that solution worked without putting the car all back together with a simple turn of the key. Paul is correct on the time to do this you need to remove your knee bolster and then the metal skeleton that the knee bolster connects too. Then three bolts that secure the tilt steering wheel column.

Unscrew tilt lever until it is almost completely out as you will need it to move the steering wheel during the screw removal process. Then just before dropping the column don’t forget to remove the tilt lever so the column will drop and not hang up on the tilt lever.

Place something under the column as there is no need for it to drop too far you are just trying to access the IP gauges surround.

While behind the guages you can trace the tach wire to the harness yadda yadda. It sound worse than it is which is why I suggest doing everything while you are there once. GC

efnfast · 04-04-2012

Thanks for that GC. What other maint. items while I'm under there.
How many bulbs are there? Are they all the same?
Are the screws and retainers all the same, or do I need to keep track of what came from where?

04-03-2012	#1
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,407	Busted tach Went for a ride today, and no tach, either that or the wind was puhing me very fast. What makes the tach not work? 1990, no trouble lights.

04-03-2012	#3
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,407	Re: Busted tach Paul, it sits right on zero, never moves. Did it once the other day, than seemed alright. I've restarted a couple times with no change. Steve

04-03-2012	#5
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,407	Re: Busted tach Oh great, this sounds like a dandy. Must be a winter project. Spring is here, I'm not going to disable it now. Are the bulbs stock items at the chevy dealer? Thanks GC.

04-03-2012	#6
VetteMed Join Date: Mar 2009 Location: Orlando, FL Posts: 1,828	Re: Busted tach The bulbs are available at rockauto.com I think the PN is PC161. It's a 194 bulb soldered into a plastic base with contacts for the printed circuit board. __________________ 2004 Z06/Z16 LeMans Commemorative Edition 1991 ZR-1 #302 White/Gray (sold) 1991 ZR-1 #1147 Red/Saddle (sold)

04-04-2012	#7
Paul Workman Join Date: Nov 2007 Location: Squires (near Ava MO in the Mark Twain N'tl Forest) - Missouri Posts: 6,493	Re: Busted tach Actually, the cluster is only about 30 min to an hour to get it out, and same to reinstal it. Add to that whatever R&R'ing to be done, and that's it. BTW, Zip has bulbs for $5.00 ea., ASSUMING you need to pull the cluster (which has not been established yet). P. __________________ 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

04-04-2012	#8
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,407	Re: Busted tach Thanks Paul, so how do we determine that the cluster needs to be pulled? GC had mentioned mice, never seen any signs. I hope not, they can make a mess. Steve

04-04-2012	#9
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,154	Re: Busted tach Steve this is part of the troubleshooting process. The pulling of the cluster and using the electrical contact cleaner is the first of many non invasive things to do. The worst case scenario is that the cluster may have do go out for a service. After cleaning you can verify if that solution worked without putting the car all back together with a simple turn of the key. Paul is correct on the time to do this you need to remove your knee bolster and then the metal skeleton that the knee bolster connects too. Then three bolts that secure the tilt steering wheel column. Unscrew tilt lever until it is almost completely out as you will need it to move the steering wheel during the screw removal process. Then just before dropping the column don’t forget to remove the tilt lever so the column will drop and not hang up on the tilt lever. Place something under the column as there is no need for it to drop too far you are just trying to access the IP gauges surround. While behind the guages you can trace the tach wire to the harness yadda yadda. It sound worse than it is which is why I suggest doing everything while you are there once. GC __________________ GOLDCYLON - 91 ZR-1 #2014 GOLDCYLON - 90 ZR-1 #2794, 4L60e (Formerly Schrade's) GOLDCYLON - 11 CTS-V Arizona State Director 91 WHITE/BLACK #2014. 380 P&P&PCed,Ported Heads, Jeal Long tubes, Corsa Exhaust/FIKSE FM-5s /LED TLs, LED Headlights, Front Wilwood 6 piston narrowlite calipers and rear Wilwood caliper street shop mod,CNCed Coolant Pipes,TPI Cvr,Filter cover,Stainless Bolts, DRM/DOM PROM /ZFDOC mod build #102,DRLs,BMAD with stainless Debris Screen,Coplan Air Blaster, Pioneer APP Radio 4,Brey-Krause HB,Sub Bar,Fire extinguisher seat mount,DRM Coilovers,LEDs everywhere,Compass mirror (orange),V1 DIC hidden display, Homelink sun visor, Carbon Fiber top x3 and APSIS Carbon Fiber interior, APSIS CF Steering Wheel/NAPA Leather, Banski trailing arms, Guldstrand front suspension,urethane bushings from Prothane (total suspension) ZFDoc drive shaft safety loop, raptor shift light (orange),AO engineering louver front plate, Console seat cushion, 96CE seats with black custom Sheepskins, ss billet catch can,Viper remote entry/alarm,Cragar Rear Louvers,LED side louver lights, Dewitts Radiator with SPAL fans and a Woods 160 T-Stat 90 RED/BLACK #2794. 4L60e Automatic Stage V by RPM Transmission, TCI Dedicated TCM, OBX Stainless Headers, Corsa Exhaust, SAN Secondaries and Haibeck PROM, Exotic Muscle Coil overs, LED Interior Lights, LED Tail Lights, LED Headlights, 94 Sport seats with black custom Sheepskins , Cragar rear louvers, GS Front calipers, Banski Trailing arms, APSIS Carbon Fiber steering wheel, Front and Rear Baer Eradispeeds, DRLs, Guldstrand front suspension,urethane bushings from Prothane (total suspension), Dewitt's Raditor with Dual SPAL fans and a Haibeck 170 T-Stat 11 RED/GREY CTS-V Last edited by GOLDCYLON; 04-04-2012 at 09:19 AM.

04-04-2012	#10
efnfast Join Date: Nov 2011 Location: Dunbarton NH Posts: 7,407	Re: Busted tach Thanks for that GC. What other maint. items while I'm under there. How many bulbs are there? Are they all the same? Are the screws and retainers all the same, or do I need to keep track of what came from where?