Charging problem - ZR-1 Net Registry Forums

Ouchdog · 07-23-2013

On my way to work yesterday i noticed that my battery light came on on my 90 ZR1 i put a multimeter on it and only had 10.50 volts with it running. I assume that the alternator is shot so i ordered one. I am going to replace the battery also. My question is can i replace the alternator without pulling the plenum and just pull the throttle body extention off. I dont think i have what it takes to pull the plenum you guys make it sound pretty hard.

thanks

Paul

John Boothby · 07-23-2013

I replaced my alternator awhile back, and it was not too hard. If I remember, I just unbolted the plenum and propped it up with a wooden hammer handle (I purchased one at Home Depot just for plenum work). You do not have to disconnect the ignition module or connections on the rear of the plenum. You will have to drain coolant by syphoning off some coolant from the upper resivor to below the inflow/outflow lines. Replace your plenum gaskets (Jerry's Gaskets) and torque using the sequince indicated in the Service Manual.

I have had my plenum off maybe half a dozen times. The first time was intimidating! After that, no sweat.

Some of the other guys might want to jump in here also.

Ouchdog · 07-23-2013

I ordered the gaskets. Can you please tell me what the service manual says about torquing the plenum bolts i don't have a service manual yet i just got the car on Saturday.

Thanks

John Boothby · 07-23-2013

Torque to 19Ft Lbs per the LT5 Service manual or 20Ft Lbs per the Corvette Service manual. Sequence is basically from the middle of the plenum alternating from side to side and outward toward front and rear. HIGHLY recommend that you get a set of service manuals (Corvette Service Manual; RPO Lt5 Service Manual Supplement and Electrical Diagnosis Manual). They arn't that expensive, they are available and essential, in my opinion.

Check the website and forum for more info. I am sure there are tech articles regarding this.

Hope this helps.

PS. Someone on this forum might be able to scan the page out of the SM showing the torque sequence and either post to this thread or email you.

ScottZ95ZR1 · 07-23-2013

I'm away from home so can't scan FSM torque sequence but see Michael's post linked below:
http://www.zr1.net/forum/showpost.php?p=52677&postcount=9

Ouchdog · 07-23-2013

Thanks guys I will let you know how it goes.

Ouchdog · 07-25-2013

It works thanks for all the help!

GOLDCYLON · 07-25-2013

Ive done it with out removing the TB or the plenum there is enough room if you simply remove the air horn. However, that being said if you have big meaty hands there is plenty of room if you remove the TB. I was in a pinch as I didnt have any TB Gaskets handy. The battery cable on the back is a bear to getting to using the Airhorn only method. It will need to be canted to roved at and angle and reinstalled the same way in a turned angle motion. GC

07-23-2013	#1
Ouchdog Join Date: Jul 2013 Location: Nebraska Posts: 5	Charging problem On my way to work yesterday i noticed that my battery light came on on my 90 ZR1 i put a multimeter on it and only had 10.50 volts with it running. I assume that the alternator is shot so i ordered one. I am going to replace the battery also. My question is can i replace the alternator without pulling the plenum and just pull the throttle body extention off. I dont think i have what it takes to pull the plenum you guys make it sound pretty hard. thanks Paul

07-23-2013	#2
John Boothby Join Date: Jul 2005 Location: Las Vegas, Nevada Posts: 775	Re: Charging problem I replaced my alternator awhile back, and it was not too hard. If I remember, I just unbolted the plenum and propped it up with a wooden hammer handle (I purchased one at Home Depot just for plenum work). You do not have to disconnect the ignition module or connections on the rear of the plenum. You will have to drain coolant by syphoning off some coolant from the upper resivor to below the inflow/outflow lines. Replace your plenum gaskets (Jerry's Gaskets) and torque using the sequince indicated in the Service Manual. I have had my plenum off maybe half a dozen times. The first time was intimidating! After that, no sweat. Some of the other guys might want to jump in here also.

07-23-2013	#3
Ouchdog Join Date: Jul 2013 Location: Nebraska Posts: 5	Re: Charging problem I ordered the gaskets. Can you please tell me what the service manual says about torquing the plenum bolts i don't have a service manual yet i just got the car on Saturday. Thanks

07-23-2013	#4
John Boothby Join Date: Jul 2005 Location: Las Vegas, Nevada Posts: 775	Re: Charging problem Torque to 19Ft Lbs per the LT5 Service manual or 20Ft Lbs per the Corvette Service manual. Sequence is basically from the middle of the plenum alternating from side to side and outward toward front and rear. HIGHLY recommend that you get a set of service manuals (Corvette Service Manual; RPO Lt5 Service Manual Supplement and Electrical Diagnosis Manual). They arn't that expensive, they are available and essential, in my opinion. Check the website and forum for more info. I am sure there are tech articles regarding this. Hope this helps. PS. Someone on this forum might be able to scan the page out of the SM showing the torque sequence and either post to this thread or email you. Last edited by John Boothby; 07-23-2013 at 07:29 PM.

07-23-2013	#5
ScottZ95ZR1 Join Date: Mar 2008 Location: Pendleton, IN Posts: 674	Re: Charging problem I'm away from home so can't scan FSM torque sequence but see Michael's post linked below: http://www.zr1.net/forum/showpost.php?p=52677&postcount=9

07-23-2013	#6
Ouchdog Join Date: Jul 2013 Location: Nebraska Posts: 5	Re: Charging problem Thanks guys I will let you know how it goes.

07-25-2013	#7
Ouchdog Join Date: Jul 2013 Location: Nebraska Posts: 5	Re: Charging problem It works thanks for all the help!

07-25-2013	#8
GOLDCYLON Join Date: May 2007 Location: Peoria, AZ Posts: 9,119	Re: Charging problem Ive done it with out removing the TB or the plenum there is enough room if you simply remove the air horn. However, that being said if you have big meaty hands there is plenty of room if you remove the TB. I was in a pinch as I didnt have any TB Gaskets handy. The battery cable on the back is a bear to getting to using the Airhorn only method. It will need to be canted to roved at and angle and reinstalled the same way in a turned angle motion. 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; 07-25-2013 at 08:53 AM.