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Topic: oil pressure gauge

in Forum: C3 Electrical

oil pressure gauge

Posted: 4/19/12 11:42pm Message 1 of 11
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Vancouver, WA - USA
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Vette(s): 1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
I installed my center gauge cluster (yeah, what a cluster that was) tonight and it appears as if my oil pressure gauge became "un-zeroed".  I didn't notice it till it was all put back together.   So is it probable that the needle rotated on it's shaft?  I've had it stored for awhile at an odd angle. Probably unlikely that it will right itself once it actually sees some oil pressure?  I turned the key on and juice is getting to the cluster, but the gauge just stays at the same location way past 80.  (About the 3:00 position).   Guess I probably need to get the dang thing outta there....Cry



 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
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Re: oil pressure gauge

Posted: 4/20/12 4:29am Message 2 of 11
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Duncanville, TX - USA
Joined: 11/8/2003
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Was the needle stuck there before you installed it? If so, I'd say the gauge itself is whacked. Not much chance of the needle twisting on the shaft, but it could have "frozen" in that position while stored, or the spring may have broken...looks like you'll need another gauge, or repair on that one.Ouch


Joel Adams
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Re: oil pressure gauge

Posted: 4/20/12 10:37pm Message 3 of 11
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Vancouver, WA - USA
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Vette(s): 1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
Thanks, Joel.  I don't know when it moved, I just know it worked (and seemed to be accurate) last time the car ran.  I'll pull it out of there and take a look.  Is there a clock spring in there that could have broken?  



 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Re: oil pressure gauge

Posted: 4/21/12 3:05am Message 4 of 11
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Sebago Lake, ME - USA
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Vette(s): 1978 Silver Anniversary L82 4spd (M21) Red Leather. Pace Car is in the hands of a new caretaker.
Does yours have that printed circuit board behind it with the copper strips on it? When mine stopped working the needle stayed pegged way up high like that. The circuit board looked a little dryed out and worn in places so I replaced it and it worked fine since. Maybe check the connection??


Re: oil pressure gauge

Posted: 4/21/12 6:28am Message 5 of 11
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Duncanville, TX - USA
Joined: 11/8/2003
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Jeff has a point. If the gauge isn't getting power, it could be stuck just about anywhere in it's sweep. I think the '76s did have the circuit boards...that would be a good place to start. Check that bugger well to make sure it is connected nice and snug on the gauge panel. 


Joel Adams
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Re: oil pressure gauge

Posted: 4/21/12 11:50am Message 6 of 11
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Germansville, PA - USA
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Vette(s): 1974 Coupe 358ci 4 speed Black w/Medium Saddle interior w/79 custom leather seats. . 1999 C5 Convertible, 6 speed, Atomic orange, Oak interior.
A nornal check for a non fuctioning gauge is to disconnect wire from sending unit and ground the wire...if gauge pegs out the gauge is good....if not sending unit is bad. I'd check for a possible grounding of a wire or on the circuit board if it has one.


   

DanT

Re: oil pressure gauge

Posted: 4/21/12 9:20pm Message 7 of 11
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Vette(s): 1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
I think I'm OK.  I took the cluster out and dis-assembled and cleaned.  I moved the needle left of zero and it slowly zeroed itself out.  I re-installed everything and needle was still reading zero.  Then turned key on and it pegged itself out.  My engine is out and of course the sending unit is removed so the gauge is seeing infinite resistance.  So I think it's doing what it's supposed to??  Is it OK to test by bridging across the connector where it plugs into the sending unit?  Should it read zero if I do that?  

Thanks for all your help, guys.  Oh and BTW, no circuit board on '76.  Only the tach has one.  Circuit board for center gauges must have come in '77 or '78.  






 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Re: oil pressure gauge

Posted: 4/22/12 7:42am Message 8 of 11
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Duncanville, TX - USA
Joined: 11/8/2003
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
The temp sending unit for the earlier, non-electronic gauge should have only one wire...dark green, driver side head. The two wire passenger side sender is for the TCS system.
Anyway...if you have the sending unit for the car, plug it into the harness, and see how it reads like that. If the gauge is pegging hot, and you're fairly certain the gauge is good, then there is a short to ground somewhere. Key "On", with the sender unplugged, the gauge should read to the left(cold). If you ground the green wire for the sending unit, the gauge will peg right(hot).
The electronic gauges work a little differently. With the key off, the gauge needle could be anywhere on the dial.



Joel Adams
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Re: oil pressure gauge

Posted: 4/22/12 12:46pm Message 9 of 11
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Vancouver, WA - USA
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Vette(s): 1976 Silver/Firethorn. L48, 4spd. Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.
Well, I plugged in the sender and grounded it and with the key on it reads zero.  Sender unplugged or not grounded it pegs hot.  I think it's the opposite of what you say, Joel since it's pegging hot with the sender unplugged and I think you say it should peg cold.  But I think I'm going to go with it since it reads zero when it's properly plugged in and grounded.  If I have to replace it later after I get the car running, I guess I'll get to tear into the center console again - oh well.  



 

1976 Silver/Firethorn.  L48, 4spd.  Original 2 bolt, vortec heads, 9.4:1 CR, Speed Pro Cam: 224/224@0.050, 112 LSA, Eagle Steel Crank.

Re: oil pressure gauge

Posted: 4/22/12 5:20pm Message 10 of 11
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Duncanville, TX - USA
Joined: 11/8/2003
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Vette(s): #1-1974 L-48 4spd Cp Med Red Metallic/Black deluxe int w/AC/tilt/tele./p/w-p/b/ Am-Fm/map light National/Regional/Chapter NCRS "Top Flight" #2-1985 Bright Red/Carmine Cp.L-98/auto Member: NCRS, NCRS Texas, Corvette Legends of Texas
Well...we all know that the '76 year models were a bit "different".....LOL LOL LOL

It must be an electronic gauge cluster, then. ALL of the older style gauges work the way I described(with the exception of the fuel gauge, which is "backwards"). Either way, if it is sweeping the needle all the way, the gauge is most likely fine. Thumbs Up



Joel Adams
C3VR Lifetime Member #56    

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             NCRS

"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"

in Forum: C3 Electrical


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