My 84 was coming along nicely but I got in it Wednesday to go someplace and there was nothing. Turn the key and no starter or dash lights. I checked the battery and it read 12.7 volts and all of the fuses were okay. I dod a continuity check on them because I don't trust them just by looks. I wire brushed the terminals and that didn't solve my problem.

I know that batteries can be weird so I took it to O'Reilly's and had it load tested and it is fine. I imagine that there is some kind of ground problem but I'm not sure where to start looking. I can see the starter not working if it was loose there but would that explain why I get no dash lights? I was working on the hatch solenoid just before this as it is not working and I have another to put in it. But the car has been starting fine and running normally.

Scratching my head here.

 

Fuseable link or maxi fuse maybe.blown. I would check voltage at fuse boxes. If there are dead fuses you will need to find out how the are powered

 

I am not sure if and how this applies to a 1984 Corvette but I will make a suggestion.

We have a 1988 C4 that sat for a time and when I tried starting it nothing would happen, no clicking, no fuel pump priming, nothing. It turned out that most of my electrical problems were coming from one little Post mounted below and behind the battery on the drivers side. It is under the body panel between door and front left side. This little post has a fairly large red wire coming directly from the battery supplying 12 Vdc to the post. The on the same post are 7 fusible links with connectors that had corroded. After wire-brushing the post and cleaning the terminals I re-assembled the post and connectors. After doing this I had full battery voltage at the fuse panel. The radio power wire went up over two volts as did the fuel pump supply voltage. Everything worked a whole lot better with full battery voltage.

You can test the fusible links but if you make a hole in the wire to test it please cover the hole or plug it so water can't get into the wire and start corrosion. This post supplies most of the car with 12 Vdc so I suspect it would be a good place to start. If it is not in the same place some 1984 owners will tell us I hope.

Good luck!
Chris

 

The '84 is different. There is no fusible link post behind the battery. The fusible links are at the starter solenoid battery cable post (a bit harder to get to).

You may have a grounding problem.
1. Check the battery voltage from the + post to the - post while trying to crank the engine. Verify 12 v.
2. Check the battery voltage from the + post to the alternator case (ground) while trying to crank the engine. Verify 12 v.
3. Check the voltage at the alternator output post (red wire) to the alternator case (ground) while trying to crank the engine. Verify 12 v.

These test verify a good ground of your negative battery cable, and a good fusible link for your starter circuit.

Please report back.

 

Thank you Hot Rod Roy!

I really appreciate your helping us with the location of that darn post. I guess that is why they moved it to the frame rail as near the battery gets crowded.

One more check would be helpful, measure the battery open circuit voltage at the battery. Then leaving the red lead on the battery positive take the black lead and touch it to the engine block to verify that your engine is grounded properly. You should get the same voltage you get reading from the battery. Engine grounds are important and they seemed to add ground straps as they went along making C4's.

Hot Rod Roy, you mentioned measuring the voltages "While trying to crank the engine". If you are measuring the battery voltage while cranking the car you will likely see 10.5 Vdc and up on the battery while loaded cranking the engine. Checking the grounding of the alternator is important but while cranking the engine? I guess I don't under stand why you have them trying to crank the engine and measure the reduced voltage due the load on the battery at that time. I use a Fluke 87 Multi-meter and it has a "Min-Max" mode which will record the upper and lower numbers during the test. I hook the meter to the battery and then crank the engine up. The voltage should not drop under 10 volts in this test and my MIN/MAX function catches the peaks to accurately show you the results of the test.

If you measure the batteries open circuit voltage (disconnected from any load) and then leave the black lead on the battery ground terminal and measure the output terminal on the alternator with the red lead you should see the same voltages. If you reverse this and leave the red lead on the battery Positive and touch the engine with the black lead you should see close to full battery voltage. The one place I am really curious about is the voltage at the source of power for the fusible links. On my Corvette it was closer to 2 volts lower than the battery voltage and that identified it as my "Problem".

I have had my 1968 C3 for 28 1/2 years and when I rebuilt the engine I had time to really look at the other wires in my engine compartment. I found that my battery Positive cable had a lump in it. The battery positive cable is real long as the battery is behind the driver. Anyway it seemed that I had corrosion ongoing in my old battery positive cable running from the battery to the starter solenoid. We cut open the old cable and somehow water had gotten inside the jacket and started corroding causing a small egg shape to appear in the battery cable. Check your wires carefully and thoroughly for any strange things like bulges or corrosion. A cable with corrosion starts making resistance and when you get enough resistance you will probably either "fuse" the wire or start a fire if the conditions are right. That particular wire is what takes the power from the alternator to the battery to charge it up and handles current going both ways. Using a 125 amp alternator I needed to upgrade the alternator output wiring and protect the 40 amp ammeter. I ran a #4 flexible wire from the alternator output to the starter solenoid and now my car stays charged but I have a useless meter in my dash. I need to install a modern voltmeter so I can see the battery voltage at any time.

In the past year I learned of a compound called DeOxIt and it does an incredible job cleaning off corrosion, it is now what I use on virtually all my connections in the Corvette. You can use DeOxIt to improve conductivity and minimize the voltage drops.

Thanks for helping me out Hot Rod Roy! I learn something new everyday.

Best regards,
Chris

 

That's exactly the same as my request to check from the + battery post to the alternator case (ground). My suggestion for doing these tests "while trying to crank the engine" is because a high resistance (bad) connection may read correctly, but will not allow the cranking current to flow, which will result in a very low voltage reading while trying to crank. It was defined by the OP that the engine would not crank, but that doesn't prove that the starter or the solenoid is defective. Since the starter won't "crank", you won't get the expected 2 v. drop in the battery voltage that you would see if the starter cranked normally, since no high current is being pulled from the battery.

In the '84, there is a fusible link between the alternator and the "hot" post on the starter solenoid. This link also feeds the ignition and starting circuits. Checking per my procedure keeps you out from under the car. If all connections and the fusible link are good, the car should start! If these test prove to be okay, we move on to other culprits . . . ya gotta start somewhere! Hopefully, the OP will respond.

 

I am not ignoring the good replies but I have been busy for the past several days. Going to tackle this today.

 

As it turns out there was nothing drastic to do to fix the window. I also had problems with the door latch. I loosened all of the fasteners and that freed up the window, regulator and the door hatches. Everything works. The car has been good to me the past week or so and I'm not complaining. Next project.