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Discussion Starter #1
Hey there,
I’ve got a 78’ nova that for whatever reason is just dying at random times. I have checked all the connections and everything seems to be wired up fine, but my in cab voltmeter is reading at lower than 12v even while I’m driving. I recently installed a brand new high voltage alternator to combat the same issue that was caused by too much draw from the stereo, which had me running at around 12.5 to 13v consistently while I was driving. When the power gets killed, I can turn the key off, wait a few seconds, and it will fire right back up. I have a two prong relay installed to the cab in the engine bay where an old fuseable link was wired, and I’m thinking that might be what is causing it to kick off. My guess is that it’s doing this because of a voltage surge from somewhere, or that the voltage just isn’t high enough to power all of the minimum required systems (this has happened with everything off but the fuel pump). The left turn signal light in cab hasn’t been flashing, and sometimes the turn signal itself won’t either. I read somewhere that the ignition and turn signals all draw from the same hot wire, so that might be something as well? It’s got me stumped and I’m really not in a place where I can afford to just retire the whole car to curb the issue... any help would be appreciated
 

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Mike - 74 Nova Baltimore, MD
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I recently installed a brand new high voltage alternator to combat the same issue that was caused by too much draw from the stereo.
Do you mean a "High Output Alternator" (higher amperage rating) was installed?

While the car is running, take a hand held volt meter and connect it across the positive (+) and negative (-) terminals of the battery to confirm running voltage. Are you still seeing under 12 volts (at the battery) with the engine running?
The "engine shut down and restart" issue you are describing would normally point to a bad ignition module in your HEI distributor. But if you are truly running at below 12 volts, the HEI may not be working properly... as it is designed to operate at 12+ volts.

Low running voltage could also explain why your blinkers are not working properly (not enough load to cycle the blinker relay/flasher). Turn on your "Emergency Flasher Switch" and check to see if all of the turn indicator bulbs are flashing. You may also need to replace your stock blinker relay/flasher with a heavy duty one.

The relay you installed (in place of the fuseable link) may also be suspect.
*Can you describe the relay that is installed in your car?... since you stated it only has 2 prongs, it may be a circuit breaker.
*Are all of the electrical needs of the vehicle going thru this relay?
*What amperage max is the relay rated for?... It is possible that the relay may be overheating due to overloading. NOTE: Since you indicated this relay is also located in your engine bay, that could also be causing this relay to overheat.
I would recommend replacing this relay with the correct fusable link (or 12 volt "heat rated" circuit breaker) that is rated to handle the amps of the "high output" alternator that you installed.
 

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Mike - all good answers -
and, I might suspect the "said relay" - - - all of my relays (for my headlights - two ea) , have 3 prongs . I , also may think that he has a 'circuit breaker' type installed. When, that - ? -
circuit breaket heats up , they quit working - - thus, the engine quits . . . cools-off - - then, engine will restart .
Thorne Malkin . . .
Remove your "relay" - - - get a 'fuse holder & insert 30 amp fuse , install metal wire ends ; and install that "jumper fuse" into that socket .
Does that make sense - - - - - you can 'jump' that just too check , too see if that "relay" may be your trouble. (if you do have something going on - - the fuse will 'blow' - - bingo ) . Drive the car (time u'r drive) . . . . see if your car keeps running.
The jumper fuse , will still proctect your wiring , just too check - too see if your car can keep running . YOU Do still need to check u'r " voltage - across u'r battery terminals
( check that battery out-put - - "charging" . . . . should see about 14v on u'r voltmeter. ( min of 13.5v , to make u'r system work - - charge ) .

14v plus - with a new 'high-output alt.


Ok - - - here's alittle story for you - - - - -

years ago, at work . . . A employee came to the shop, came over too me : "Can you check my 'tail-lights' . . . I can not stop them from "the left rear keeps flashing" . . . . .
"I have had people stop - knock on my door - & tell me my lights are FLASHING ! "
This has been going on over a week, by now ! So, I check the Rt rear tail light - - bulb was burned-out. As soon as I installed the R/R bulb - - it started too Flash .
Bingo = = = = she- had been driving around - with her 4-way-flashers going. For over a week - - until it started burning out bulbs . . . . that's why other people told her - - that her lights were flashing. She , never caught-on .

Check all of your lights - - front & back - - check that u'r 4-way lights are not on . - - - - let us know how you fix your problem . . . . I hope this will help . . . . .
. . . . I'm just saying . . . . jim

and , WELCOME to SNS , glad to have you with us . . . .
 

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Discussion Starter #4 (Edited)
Thank you all! I’m discovering now that the accessories might still be drawing too much, or that my alternator may be going bad (I did mean high amperage alternator, I was just really tired the night I posted). I did check the breaker relay by cutting it out of the circuit and running a fuse in its place, but all seems to be fine there. I replaced it, because it has saved me a lot of pain and fuses in the past from hot wires melting to hot headers and other fuse killing issues (it is rated 12v and it’s survived the long four years the car has been floundering back to life, so I’m thinking it’s probably heat resistant as well). The battery is reading 13.5 when it is running, but The overall voltage is dropping while I’m driving to anywhere between 11.8 and 12.5. I’m beginning to think the stereo might be what is tipping the voltage to sub-12, although it has been running fine up until this point six months later. What concerns me is while I am at idle, I can see the voltage decreasing gradually, which has me thinking the alternator may be going. I went with a tuff stuff 250 amp alternator from summit around five months ago, and it’s kind of disappointing that it might already be going bad. Do you guys have any recommendations brand or model wise for increased amperage alternators? Also, for future reference, the flashers and headlights seem to be pulling a ton of power. Would swapping to halogens be beneficial? Thanks :)
 

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Mike - 74 Nova Baltimore, MD
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*What type of voltage gauge are you using in the car when viewing the lower volts?
*When you are showing between 11.8 and 12.5 volts on the vehicle's gauge, what is the volt reading across the battery terminals?
*Does the vehicle's volt gauge ever show 13.5 volts?
*What kind of stereo system (and amps, speakers, etc) do you have installed in your car that has you concerned about amperage draw?

With the engine off, all lights & accessories turned off, and all doors shut > disconnect just one of the wires connected to the battery terminal and run a test light (or a volt meter) from the end of the wire to the battery terminal. What happens?... you should show no light or voltage.

It might be a good idea to take you Nova to an AutoZone or Advanced Auto and have them do a free charging system test.

P.S.... What happened when you turned on your emergency flashers? Did all the blinker lights flash?
 

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Discussion Starter #6
Hey all, I may have discovered the issue bud I haven’t had enough time to re-evaluate and see if everything is completely resolved. I was on my way to the airport today and I herd a pop and then a bunch of very loud clicking coming from the engine bay. There wasn’t an increase in vibration and the car was still running at the same tempo as before, so I pulled off and popped the hood. The left(passenger) rear spark plug has apparently been working itself loose and the high compression from highway driving must have finally popped it out of the socket. I think it may have been arcing to a header bolt or something close , and just stayed in place because of the plug wire. I screwed it back in and the car fired right up and the voltage immediately started rising from a flat 12 to around 13.15 over the rest of the drive to the airport. She was running a little rough before, but I had figured that was due to the shop that redid the intake manifold gaskets timing it a little rough. Now it’s running smooth as butter. Thank you guys for all the help, I’ll be sure to let you know if anything else changes or if the problem persists.
 

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Discussion Starter #7
*What type of voltage gauge are you using in the car when viewing the lower volts?
*When you are showing between 11.8 and 12.5 volts on the vehicle's gauge, what is the volt reading across the battery terminals?
*Does the vehicle's volt gauge ever show 13.5 volts?
*What kind of stereo system (and amps, speakers, etc) do you have installed in your car that has you concerned about amperage draw?

With the engine off, all lights & accessories turned off, and all doors shut > disconnect just one of the wires connected to the battery terminal and run a test light (or a volt meter) from the end of the wire to the battery terminal. What happens?... you should show no light or voltage.

It might be a good idea to take you Nova to an AutoZone or Advanced Auto and have them do a free charging system test.

P.S.... What happened when you turned on your emergency flashers? Did all the blinker lights flash?
Yeah, they all flashed. I believe I found the issue with the loose spark plug, I mentioned below, but I will test the battery like you mentioned. I have a voltage gauge installed in the cab, but I had my voltmeter hooked up to a hot and a ground as well that was giving me the same data. Hopefully all that I need to fix this is a heali coil for the spark plug that shook loose and some lock tire for the rest of them. I’ll be sure to add to the post if anything changes
 

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i never heard of using lock tight on spark plug threads.
 
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This is kind of weird. I never heard of a spark plug backing out like that but ya learn new stuff every day. Who was the last person to install the spark plug? How long ago? Did they remove the plug when they replaced the intake gasket for some reason? Did the spark plug tighten when you put it back in? I don't think I'd put a helicoil in if the plug tightened when you put it back in. Never heard of using Loctite on plugs either. I would suspect that the plug was never tightened when it was installed.
 

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Discussion Starter #10
Yeah, they all flashed. I believe I found the issue with the loose spark plug, I mentioned below, but I will test the battery like you mentioned. I have a voltage gauge installed in the cab, but I had my voltmeter hooked up to a hot and a ground as well that was giving me the same data. Hopefully all that I need to fix this is a heali coil for the spark plug that shook loose and some lock tire for the rest of them. I’ll be sure to add to the post if anything changes
This is kind of weird. I never heard of a spark plug backing out like that but ya learn new stuff every day. Who was the last person to install the spark plug? How long ago? Did they remove the plug when they replaced the intake gasket for some reason? Did the spark plug tighten when you put it back in? I don't think I'd put a helicoil in if the plug tightened when you put it back in. Never heard of using Loctite on plugs either. I would suspect that the plug was never tightened when it was installed.
You are probably right about that, and to be honest I haven’t either. It’s possible they took it out, but it’s more likely it just wasn’t as tight as it should have been. It’s in a really hard to reach place. I was thinking a dab of blue loctite on that spark plug because it had stripped threads towards the front, and I want to avoid that happening again. The heads are aluminum, so I’m a little reluctant to torque them down super hard
 

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Hey there,
I’ve got a 78’ nova that for whatever reason is just dying at random times. I have checked all the connections and everything seems to be wired up fine, but my in cab voltmeter is reading at lower than 12v even while I’m driving. I recently installed a brand new high voltage alternator to combat the same issue that was caused by too much draw from the stereo, which had me running at around 12.5 to 13v consistently while I was driving. When the power gets killed, I can turn the key off, wait a few seconds, and it will fire right back up. I have a two prong relay installed to the cab in the engine bay where an old fuseable link was wired, and I’m thinking that might be what is causing it to kick off. My guess is that it’s doing this because of a voltage surge from somewhere, or that the voltage just isn’t high enough to power all of the minimum required systems (this has happened with everything off but the fuel pump). The left turn signal light in cab hasn’t been flashing, and sometimes the turn signal itself won’t either. I read somewhere that the ignition and turn signals all draw from the same hot wire, so that might be something as well? It’s got me stumped and I’m really not in a place where I can afford to just retire the whole car to curb the issue... any help would be appreciated
 

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Most elec probs are related to issues with 'grounds' Start @ batt. then check 4 good batt to body ,good batt to motor, good alt to motor. Sum connections will test good , but go open under load. Been fooled by that B4. Fully chgd batt is 12.6v. No 12v conn should b over .5v lower. A reliable VOM meter and good quality test lite r a must to avoid 'chasing ur own tail' .Happy hunting
 

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Shouldn't the spark plug boot be pretty tight on the plug. I know on mine I have to twist it off to get it off the plug which would seem to not allow it to just work it's way loose, but I also understand it should have been tightened. Maybe your spark plug boots are worn or bigger than they should be on the plugs. Also you shouldn't need any kind of thread locking liquid and should just need to tighten it down.

Also, make sure you have lots of ground straps. I had the same issue, although my battery was in the trunk but I'd drive 30 mins at night and my voltage would drop below 12v by the time I got home with the head lights on. I added a few ground straps and that helped tremendously. I was still showing some voltage drop at different points between the engine and the battery. A few months back I went and bought some thick gauge wire from Lowes to run from my starter bolt to the battery in the back and now I'm running at anywhere from 12.5 - 14volts consistently with lights and radio on. Also I have a Tough Stuff alternator and it works great and I've had it for a couple of years. I believe mine is a 140 amp or something around that range, but I also do not have an amp. As said already take it and get it checked before buying another one. It may not be the alternator and just some simple grounds are needed.
 

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This is kind of weird. I never heard of a spark plug backing out like that but ya learn new stuff every day. Who was the last person to install the spark plug? How long ago? Did they remove the plug when they replaced the intake gasket for some reason? Did the spark plug tighten when you put it back in? I don't think I'd put a helicoil in if the plug tightened when you put it back in. Never heard of using Loctite on plugs either. I would suspect that the plug was never tightened when it was installed.
Properly torqued plugs won't bak out even tho most pros use Anti-sieze on threads. Compromixed threads must be fixed be fore mo bad things happen. Eng spitting out a plug seldom occurs conviently
 
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