1973 Electrical Issue
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Joined: Dec 2005
Posts: 76
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From: St Louis MO
1973 Electrical Issue
Hi,
Had a little adventure and looking for some thoughts. Started the 73 this morning, no problem. Runs for a couple minutes, no water temp indication, laying all the way to the left on the peg, no signal. Also notice the power windows do not work and the turn signals do not work.
Put a voltmeter on the alternator, 14+ VDC. Check voltage at battery, 14+VDC. Check a couple other things, the headlights do work, the air conditioning and blower motor work and the radio works.
I do not have a wiring diagram handy, does anyone know what is common between the turn signals, the water temp gage and the power windows?
Now for the interesting part, suddenly after about 5 minutes, all of the components that were not working suddenly come to life. I hate gremlins like this. It is far easier to find an issue when it stays inoperative. Would like to figure this out before Bloomington. Any help is appreciated.
knbwag
Had a little adventure and looking for some thoughts. Started the 73 this morning, no problem. Runs for a couple minutes, no water temp indication, laying all the way to the left on the peg, no signal. Also notice the power windows do not work and the turn signals do not work.
Put a voltmeter on the alternator, 14+ VDC. Check voltage at battery, 14+VDC. Check a couple other things, the headlights do work, the air conditioning and blower motor work and the radio works.
I do not have a wiring diagram handy, does anyone know what is common between the turn signals, the water temp gage and the power windows?
Now for the interesting part, suddenly after about 5 minutes, all of the components that were not working suddenly come to life. I hate gremlins like this. It is far easier to find an issue when it stays inoperative. Would like to figure this out before Bloomington. Any help is appreciated.
knbwag
Burning Brakes
Joined: Sep 2005
Posts: 1,050
Likes: 205
From: Lewes Delaware
Check the grounds to the gauges and the console and also fuses, specifically 12V connections. Also connections to the relays on the firewall.
Send your email address in a pm to Forum member "papawana" and request a wiring digram for a 1973. He will send you a pdf file of the diagram. He has a post now in the C3 General section of this Forum.
Good luck. Fran
Send your email address in a pm to Forum member "papawana" and request a wiring digram for a 1973. He will send you a pdf file of the diagram. He has a post now in the C3 General section of this Forum.
Good luck. Fran
Last edited by Blue73Shark; Jun 5, 2013 at 04:38 PM.
Thread Starter
Advanced
Joined: Dec 2005
Posts: 76
Likes: 0
From: St Louis MO
Hello all,
I have checked grounds in various locations and still the problem exists. Is it possibly the ignition switch?
I discovered an interesting twist last night. Started car, everything worked. After about 30 minutes same symptom as before, no turn signals, no power windows, etc. Shut the car off and restarted it, all systems came back to life immediately.
I have checked grounds in various locations and still the problem exists. Is it possibly the ignition switch?
I discovered an interesting twist last night. Started car, everything worked. After about 30 minutes same symptom as before, no turn signals, no power windows, etc. Shut the car off and restarted it, all systems came back to life immediately.
Melting Slicks
Joined: Apr 2001
Posts: 2,030
Likes: 363
From: Lubbock Texas
Hello all,
I have checked grounds in various locations and still the problem exists. Is it possibly the ignition switch?
I discovered an interesting twist last night. Started car, everything worked. After about 30 minutes same symptom as before, no turn signals, no power windows, etc. Shut the car off and restarted it, all systems came back to life immediately.
I have checked grounds in various locations and still the problem exists. Is it possibly the ignition switch?
I discovered an interesting twist last night. Started car, everything worked. After about 30 minutes same symptom as before, no turn signals, no power windows, etc. Shut the car off and restarted it, all systems came back to life immediately.
If I remember correctly, the turn signal fuse and the gauge fuse both come off of the ignition buss in the fuse block. I think that the power window relay signal wire is also fed from that location. Are you having issues with any of the other gauges?
It could be you have a loose connection in the fuse block. Check the screws that hold the fuse block to the engine compartment connector. If they are loose, tighten them up and see what happens. If not you might need to separate the fuse block from the engine side connector and clean all connections while looking for wires that may be broken and connecting intermittently. I went through this exercise awhile back while chasing an intermittent electrical gremlin.
Thread Starter
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Joined: Dec 2005
Posts: 76
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From: St Louis MO
DC3,
Thanks for the suggestion. Yes, when the systems stop working the fuel gage stops along with the water temp. The clock keeps working, oil pressure is direct reading and ammeter keeps working.
Cheers,
B
Thanks for the suggestion. Yes, when the systems stop working the fuel gage stops along with the water temp. The clock keeps working, oil pressure is direct reading and ammeter keeps working.
Cheers,
B
Thread Starter
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Joined: Dec 2005
Posts: 76
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From: St Louis MO
DC3,
Not sure if this was what you meant, I went to the wire harness connection in the engine compartment just below the power brake booster and loosened the bolt in the center that holds the harnesses in the fuse block. The ignition harness had a lot of some sort of grease on several terminals. Using contact cleaner and cotton swabs I cleaned all of the terminals and reassembled the connection. Right now everything is working, I guess we'll see if that resolved the issue. Thanks.
Not sure if this was what you meant, I went to the wire harness connection in the engine compartment just below the power brake booster and loosened the bolt in the center that holds the harnesses in the fuse block. The ignition harness had a lot of some sort of grease on several terminals. Using contact cleaner and cotton swabs I cleaned all of the terminals and reassembled the connection. Right now everything is working, I guess we'll see if that resolved the issue. Thanks.
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Melting Slicks
Joined: Apr 2001
Posts: 2,030
Likes: 363
From: Lubbock Texas
Yes that's what I meant. I couldn't remember how the harness connection in the engine compartment separated from the back of the fuse block.
DC3,
I don't have a diagram to refer to at the moment but that sounds right that the fuel gauge would stop working along with the water temp. Oil pressure and ammeter definitely don't go through that fuse block connection.
Sounds like your work on the connections has you back in business. If it happens again, double check the crimps on all of the connectors to make sure they are tight. You could also use a small wire brush to better clean the contacts than by using the cotton swab. Disconnect the ground cable from the battery before using a metal brush.
My problem was an intermittent issue with no brake lights. Turned out that the fuse holder was not making good contact with the fuse. Too many years of crud on the contacts. I ended up using contact cleaner and a wire brush to get the contacts clean again on all the fuse holders and on the connections from the engine compartment wiring harness connector.
DC
DC3,
Sounds like your work on the connections has you back in business. If it happens again, double check the crimps on all of the connectors to make sure they are tight. You could also use a small wire brush to better clean the contacts than by using the cotton swab. Disconnect the ground cable from the battery before using a metal brush.
My problem was an intermittent issue with no brake lights. Turned out that the fuse holder was not making good contact with the fuse. Too many years of crud on the contacts. I ended up using contact cleaner and a wire brush to get the contacts clean again on all the fuse holders and on the connections from the engine compartment wiring harness connector.
DC