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The 77' has worked fine for years. Had the battery unplugged this winter (bought a trickle charger for the future). Plugged back in and clicked but didn't start. Then it was dead, no clicking, nothing. I tried jumping the battery and saw smoke come from the alternator and maybe even an area near the firewall inside the engine bay, does that make sense?
I just put a new battery in and the car tries to start. Tries and tries but just wont kick over that final step (whatever it is) and turn on.
Any diagnostic help would be greatly appreciated! Do I need to check any fuses? Do I need to check any ground wires?
So now when you try to start it there is no longer smoke from the alternator and near the firewall? It just fails to start? I would check to see if you have any fire to the sparkplugs....
Smoke coming from area near the firewall. Near the brake booster? There is a fusible link there. Did you smoke it? Was the first battery hooked up backwards?
Also under the brake booster on my early 77 is a plastic covered gang connector. Where a number of power wires are connected together. I melted mine years ago. Obviously I replaced it and car has been fine.
With a test light check that your getting power to the distributor at the "Batt" wire with key on.
It is important to know if your 1977 is a early or late build as the electrical is completely different in several areas.
We don't need to know your VIN number but is the last 5 numbers of your VIN below or above 27372?
You have ignition to starter and it cranks that is a promising sign...
It is important to know if your 1977 is a early or late build as the electrical is completely different in several areas.
We don't need to know your VIN number but is the last 5 numbers of your VIN below or above 27372?
You have ignition to starter and it cranks that is a promising sign...
hey thanks!
the vin is higher than the number you presented. Does that lead you to any next step thoughts??
So now when you try to start it there is no longer smoke from the alternator and near the firewall? It just fails to start? I would check to see if you have any fire to the sparkplugs....
I only ever had smoke from those areas while the jumper cables were connected in effort to jump the battery. Once pulled off, the smoke went away and hasn’t shown up since.
How do I check for “fire to the spark plugs?”
I’ve been wondering by, now that the battery isn’t the problem, what the next likely culprits are? I figure the alternator, starter and/or maybe some fuses. The spark plugs are now added to that list lol
thanks for you help!
Smoke coming from area near the firewall. Near the brake booster? There is a fusible link there. Did you smoke it? Was the first battery hooked up backwards?
Also under the brake booster on my early 77 is a plastic covered gang connector. Where a number of power wires are connected together. I melted mine years ago. Obviously I replaced it and car has been fine.
With a test light check that your getting power to the distributor at the "Batt" wire with key on.
if the brake booster is on the firewall, higher near to the hood an led on the passenger side, then yes, smoke seemed to come from that area also.
What tool do I need to check the distributor is getting power?
thanks for your help!
hey thanks!
the vin is higher than the number you presented. Does that lead you to any next step thoughts??
So as for now lets assume you have a Late Build 1977.
Forum member 4-vettes talked about checking voltage at the BAT connector on the distributor cap with ignition switch in the ON position.
Do you have a volt meter, as a test light will not work for this test?
Do you know how to use a meter?
Do you have a Harbor Freight tools near you?
I will give you a couple links from Harbor Freight on a cheap voltage meter and a spark tester.
The spark tester simply plugs into the spark plug wire and the rubber boot end attaches to spark plug, ignition on crank engine over, there is a light inside that will flash IF it receives that signal to spark.
Spark Tester LINK: https://www.harborfreight.com/search?q=spark%20tester
Different Multimeters LINK:https://www.harborfreight.com/electr...s-testers.html
Personally out of the 3 on the link the CEN-TECH for $22.99 would be my pick as it has detachable wire leads.
So as for now lets assume you have a Late Build 1977.
Forum member 4-vettes talked about checking voltage at the BAT connector on the distributor cap with ignition switch in the ON position.
Do you have a volt meter, as a test light will not work for this test?
Do you know how to use a meter?
Do you have a Harbor Freight tools near you?
I will give you a couple links from Harbor Freight on a cheap voltage meter and a spark tester.
The spark tester simply plugs into the spark plug wire and the rubber boot end attaches to spark plug, ignition on crank engine over, there is a light inside that will flash IF it receives that signal to spark.
Spark Tester LINK: https://www.harborfreight.com/search?q=spark%20tester
Different Multimeters LINK:https://www.harborfreight.com/electr...s-testers.html
Personally out of the 3 on the link the CEN-TECH for $22.99 would be my pick as it has detachable wire leads.
this is all great stuff! I don’t have a Harbor freight but I can find those tools somewhere. I’ll find the items and give it some testing this weekend.
You most certainly CAN test for power going to your distributor with a simple test light. No. it won't give you an exact voltage. But it will at least let you know if your getting power or not.
OP doesn't even know what a brake booster is.
I say let's keep this simple.
Smoke rising up on the passenger side by the firewall. (No where near the brake booster). Would indicate that perhaps one of the fusible links has fried. Late 77 has 2 fusible links at the starter. Smoke would rise up from there.
No it's not possible to put the Smoke back in the wires.
Testing for power is just a quick test to see if this is a possibility.
Me, I would be under that car checking those fusible links if I seen smoke rising. And now the car doesn't start.
Still, all this seems strange. From the G.M. Electrical Troubleshooting Manual.
two fusible links. yet one is for lighting circuit. The other for everything else.
Power coming into the main switch. power feeds starter wire and power out to distributor.
Rising smoke needs to be explained. And with a 45 year old car who knows what has been done with the wiring.
Still, all this seems strange. From the G.M. Electrical Troubleshooting Manual.
two fusible links. yet one is for lighting circuit. The other for everything else.
Power coming into the main switch. power feeds starter wire and power out to distributor.
Rising smoke needs to be explained. And with a 45 year old car who knows what has been done with the wiring.
these diagrams are awesome.
I’ll be checking the wiring and fusible links tomorrow. Any specific signs I should be keeping an eye out for?
as for the wiring, I’m pretty positive the only non original wiring is when a modern (10 year old) stereo system was installed. Aside from that the car is quite original.
I know each of the three previous owners and it was 100% original car until my dad and I got it. It’s set to be a resto-mod of sorts in its future.
You need to purchase a Gen. G.M. Electrical Troubleshooting Manual. Look around on ebay. Full of easy to understand wiring diagrams as well as descriptions of where components and connections are.
it's gold!
First, anytime working on or near the starter disconnect the battery cables.
If you still have headlights, that would be Fusible link "B" and your definitely able to crank the car I would bet Both Fusible link(s) "A" & "B" are good.
Just a brief on Fusible Link(s) to keep in your memory bank.
On a late 1977 both (lets label them as the troubleshooting manual does) Fusible Link "A" and Fusible Link "B" are connected to the main battery cable large lug on the starter solenoid.
Fusible Link "A" is a 14 gauge and Fusible Link "B" is a 16 gauge.
You will notice there are, or originally were two White or dirty plastic capsule, this is the splice point of where the main harness wire is crimped and solider to the Fusible Link wire.
I have seen Fusible links that the wire has burned in half, I have also seen failed Fusible links that you can still read the wire gauge size on the insulation, so there is no defined description of a failed Fusible link other than it will no longer pass current.
I will provide a photo of the location of the 2 Fusible links from my Late Build 1977..
Using a test light will indeed get you to Step 3 of 10 as outlined in the 1977 Chevrolet Passenger Car Service Manual.
The physical locations of the Fusible links varies from year to year but they are clearly something you want to check. If I can't easily see both ends of the fusible link's wire I have put a needle thru the wire allowing me to verify continuity or voltage through the fusible link. Generally on fusible links near the Starter the power is coming from the battery connection at the starter. By pushing a needle thru the wire past the fusible link so you can measure the voltage after getting through the fusible link. Fusible links can wear over time and that can make them more susceptible to burning out more easily. If you do test one of the links with any kind perforation be sure to seal the hole in the wire's insulation when done. You don't want any moisture to get into the wire through the hole and cause corrosion on the wire. I use liquid electrical tape on the outside of the wire to seal the penetration if one is made or found on the electrical harness. If you want to use heat shrink that too will work as long as it covers the hole effectively. Marine grade heat shrink has the same ability to shrink but adds a heat activated glue on the inside to ensure a good sealed connection. Inexpensive electrical tape will come off very easily and leave the hole exposed.
The local NAPA stores carry replacement fusible links of various sizes as does our local Pep Boys. I solder the new fusible link in line where the old one was and then cover the solder connections with heat shrink.
The Fusible Links are the "last protection" of the wiring harness. If a fuse blows it should not affect the fusible link. If someone puts a larger rated fuse in place of the original fuse then the possibility of blowing the fusible link increases. A slow blow fuse can help the fusible link get blown as well. They can also fail when a power accessory is attached the the power side of the fuse in a fuse block instead of the fuse protected side. A simple way to figure out which is which is to pull the fuse and see which end has power and which does not with the fuse removed. If any power is drawn from the power end of the fuse then you can and will burn out the fusible link if there is any short.
Do not assume that a fusible link is good because the wire "appears" okay on the outside. You need to measure the voltage on the output of of the fusible link to be absolutely sure. I have seen plenty of cars where the owner puts the power connection for a new accessory on the power end the fuse thus rendering the fuse ineffective in the power circuit. It is very easy to do if the installer is not checking the wiring as he or she goes.
On later Corvettes we have seen corrosion where the fusible link gets their power and this can lead to a lower voltage due to the corrosion. Be sure to measure the voltage of the battery and then measure what is getting through the fusible link. On the C4's we simply measure the battery voltage and then measure the voltage available at each of the fuses on the side that supplies the power. If there is a difference then you have a bad connection in between the battery and the fuse block.
Testing to see if the spark plug is getting power can also be done with a standard timing light. Connect it like you normally would and then check to see of the light is flashing while the engine is cranking. Then you can move the #1 probe from cylinder to cylinder to see if they are all getting power to spark.
Harbor Freight multi-meters and not only inexpensive but they are cheaply made as well. I would recommend people stay away from the less expensive units as they do not last very long and are made of questionable quality. I would suggest this is one place that you spend a few more dollars and get a quality multi-meter. I typically buy a Multi-meter that has a Min-Max function which makes testing things like the battery much easier. Home Depot sells a name brand unit for less than $60 that includes this function and the meter can last you a lifetime. With the Min-Max function testing your battery is a one person affair as the meter can capture how low the voltage goes while cranking the engine.
You guys are amazing!!!
i have ordered the troubleshooting book and assembly manual. They may take a couple of weeks to show up though. In the meantime, I’m removing the entire interior of the car, for a multitude of reasons. Most related reason to this, I’ll have east access to see and track all wires as best as possible.
i plan to tame the entire fuse box out and clean it up as well as getting all new fuses. Some fuses have a red hue in a portion Of it or a yellow smattering of color. Some fuses aren’t even fully compressed into their location etc. etc.
I’m also going to try to locate the fusible links so I can begin up walk through your in depth directions!
This is fun…so far lol.
i really want to get the car back to consistently starting and as reliable as possible. From a Mechanical and electrical standpoint, lofty goal, I know.
Engine won't turn over (on)
