1969 gauges inoperative
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Joined: Nov 2006
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From: New York
1969 gauges inoperative
I just fully restored a 1969 corvette. As far as interior electrical, everything works: speedo, tach, lighter, gauge lights, courtesy lights, bright indicator, door ajar, seat belt warning, headlamp warning, fan, wipers, etc. The strange thing is NONE of the gauges work. NO fuel, ammeter, oil pressure, water temp, and of course no clock. The car has original wiring BUT I redid all the sensors (complete new gas tank assembly with sensor, new water temp sensor, alternator rewired, etc.) Why would none of them work? Do they have some kind of common hookup between all of them? Everything seems to be wired correctly. Any ideas, help or insights would be much appreciated. Thanks.
Last edited by US300hp; Aug 30, 2016 at 03:17 PM.
Racer
Joined: Apr 2016
Posts: 493
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Maybe not related to yours, but when I put my center cluster back in for the last time (for now any way haha), I had no gauges either. I checked the fuse block and found the instrument fuse blown. I musta touched something, because when I replaced it and turned on the key, everything worked.
I hope it's that simple for you too!!!
I hope it's that simple for you too!!!
Team Owner
Joined: Jul 2006
Posts: 22,195
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From: Kannapolis NC
Certainly check the fuse first. They all share a ground at the instrument cluster. so verify that.
Edit: This was a rare occasion I used my smart phone and spoke the words, I said "comma" and instead of inserting it, it spelled it.
I just meant check cluster ground.
Edit: This was a rare occasion I used my smart phone and spoke the words, I said "comma" and instead of inserting it, it spelled it.
I just meant check cluster ground.
Last edited by 65GGvert; Aug 30, 2016 at 07:41 PM.
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Joined: Nov 2006
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From: New York
Yes I checked the fuse box first and tested all the contacts in it. All is good. Wished it was that simple too!! Where exactly is the instrument cluster comma ground? That's what I thought it could be also but couldn't locate it.
Racer
Joined: Apr 2016
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I'm pretty sure mine was on the trans hump. There was another ground wire that ran into the harness, and out in the engine compartment, I think. Don't quote me on that one. I ran all kinds of additional grounds on mine this time. From the battery ground at the frame, I went to the bellhousing, then to each head (aluminum heads this time), then to the intake. I went from the starter to the motor, and to the frame. I've had ground issues before, but not this time.
Le Mans Master
Joined: Aug 2006
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
The instrument cluster is GROUNDED by the center lug of the temperature gauge.
Not shown here but the center gauge tach and speedometer use the same black wire which attaches to the "A" pillar.
Since you have instrument gauge lights, your ground is good!
The problem is elsewhere.
Not shown here but the center gauge tach and speedometer use the same black wire which attaches to the "A" pillar.
Since you have instrument gauge lights, your ground is good!
The problem is elsewhere.
Le Mans Master
Joined: Aug 2006
Posts: 7,427
Likes: 1,560
From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Are the gauges good?
Are you sure the lighter works because the lighter and the clock are on the same fuse?
Is the oil gauge is mechanical?
Connects directly from the engine to the gauge?
Temp gauge and the gas gauge can be tested.
With the KEY ON remove the sensor line and note the readings then ground the wire and note the readings.
The gauges should go to zero and to full if they are working.
Ammeter wire connects at the solenoid BATTERY post and ends at the gauge.
The other wire goes from the gauge to the horn relay and then on to the alternator.
Is the oil gauge is mechanical?
Connects directly from the engine to the gauge?
Temp gauge and the gas gauge can be tested.
With the KEY ON remove the sensor line and note the readings then ground the wire and note the readings.
The gauges should go to zero and to full if they are working.
Ammeter wire connects at the solenoid BATTERY post and ends at the gauge.
The other wire goes from the gauge to the horn relay and then on to the alternator.
Le Mans Master
Joined: May 2003
Posts: 8,877
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From: Fernandina Beach FL
2023 Restomod of the Year finalist
2020 C3 of the Year Winner - Modified
OIL-First of all the oil pressure gauge should work- as it's mechanical...if the line is connected between the engine and gauge w/ no kinks - have oil and the oil pump is working- you have a bad gauge.
CLOCK-You have a ground- as the gauge lights work- and the cigarette lighter works- than more than likely the clock is broken.
AMMETER- you said you rewired the alternator- depending how you did that- the ammeter might not read correctly if at all.
TEMP and FUEL - have a common power wire- its hot w/ ignition and in the start position. That needs to be checked- the pink wire. If it has power take the green temp wire under the hood and connect it to a good ground. With ignition on it should peg.
Fuel sensor replaced- is the tank grounded?
Richard
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