Chevy Tri Five Forum banner
1 - 20 of 30 Posts

·
Registered
Joined
·
83 Posts
Discussion Starter · #1 ·
I was having an intermittent problem with the Gen light (Alt. Conversion) staying on, No turn signals, No fuel gauge. I could fiddle around with the ignition switch and the problem would go away. My mechanic just replaced the switch for me and now the car starts but won't stay running. Any ideas I could relay to him?
 

·
Registered
Joined
·
1,773 Posts
I was having an intermittent problem with the Gen light (Alt. Conversion) staying on, No turn signals, No fuel gauge. I could fiddle around with the ignition switch and the problem would go away. My mechanic just replaced the switch for me and now the car starts but won't stay running. Any ideas I could relay to him?
Look at harness for switch where it plugs in and all the connections. Sounds like a burnt connection to me
 

·
Registered
🐔County, TN. 55 Bel Air Sport Coupe
Joined
·
10,620 Posts
If it stalls as soon as you release the switch from the cranking position, it's in the distributor ballast wiring. Even if it doesn't still use a ballast resistor, it is still in that circuit.
 

·
Registered
Joined
·
7,723 Posts
If the ballast resistor, or wire was bad it wont fire. So if it's firing, but then dies when you release the key from the start position it's likely losing power in the run position. Need to make sure that when you turn the key to run (not start) that you read 12v. or more at the input side of the ballast resistor. Output side will likely be more like around 9v. to the coil.
 

·
Premium Member
Joined
·
243 Posts
Just follow this wiring diagram and you should be good to go by the first of the year.
1957 chevy ignition switch
Ignition switch is wired wrong for start and run voltage , JMO
 

·
Registered
🐔County, TN. 55 Bel Air Sport Coupe
Joined
·
10,620 Posts
If the ballast resistor, or wire was bad it wont fire. So if it's firing, but then dies when you release the key from the start position it's likely losing power in the run position. Need to make sure that when you turn the key to run (not start) that you read 12v. or more at the input side of the ballast resistor. Output side will likely be more like around 9v. to the coil.
If the ballast resistor is bad or a problem with its wiring, it will do exactly what I said. The ballast resistor is bypassed when cranking to give the coil full voltage when it needs it the most, while cranking which lowers the battery voltage.
Yes, it is loosing power in the run position, after letting the key loose. That is the run position. It has power in the start position which again is when the ballast resistor is being bypassed.
 

·
Registered
🐔County, TN. 55 Bel Air Sport Coupe
Joined
·
10,620 Posts
Need to make sure that when you turn the key to run (not start) that you read 12v. or more at the input side of the ballast resistor. Output side will likely be more like around 9v. to the coil.
No. If the key is in the run position, IF the points are open (or your electronic ignition isn't firing), then you should have the same voltage as the battery on BOTH sides of the coil. If the points are closed (or your electronic ignition is firing), then you should have around 9 volts to the positive side of the coil and close to Zero on the negative side. That is if there is a ballast resistor in the circuit. If the ballast resistor is bypassed, then the positive side of the coil will have closer to to full battery voltage. (the actual voltage depends on the quality of the wiring and the switch, better wiring-higher voltage.)
 

·
Premium Member
Joined
·
243 Posts
A couple of questions?
What distributor do you have, points or electronic ?
Do you still have a resister ( a white block on the fire wall with 2 wires) used with points dist.)
When your mechanic installed a new ignition switch, what year did he use?
57 Chevy's ignition switch had a run and a start terminal , similar to 55-56 switch, google it.
If he used a 55-56 switch, you need to jump IGN#1 and IGN #2
If he used a 57 only switch, there are terminals for start and run(google the switch and wire set up.)
If you have burned wires, you should have blown fuses also.
I do not think you have a major issue, I think your mechanic installed a tri-five switch, and it is wired wrong.
Just my thoughts, but I have been wrong before, good luck, let us know what you find.
 

·
Registered
Joined
·
83 Posts
Discussion Starter · #13 ·
There were two problems ( so far) . There was a bad wire to the ignition switch. Thanks Shadetree. I thought we were done until I pulled out and noticed the GEN light was on gauges and turn signals didn't work. We were only getting 12 Volts at the battery and alt. He found a connection issue with the Alternator wiring. He said this was most likely the original problem. I drove it home only a mile away from the shop and all was well. Tomorrow night is Cruise night which will be the real test.
 

·
Registered
Joined
·
7,723 Posts
No. If the key is in the run position, IF the points are open (or your electronic ignition isn't firing), then you should have the same voltage as the battery on BOTH sides of the coil. If the points are closed (or your electronic ignition is firing), then you should have around 9 volts to the positive side of the coil and close to Zero on the negative side. That is if there is a ballast resistor in the circuit. If the ballast resistor is bypassed, then the positive side of the coil will have closer to to full battery voltage. (the actual voltage depends on the quality of the wiring and the switch, better wiring-higher voltage.)
Since I've recently replaced my ballast resistor, and checked voltage at both sides, I know the output of the ballast resistor is not the same on both sides. And ignition voltage through it is the same cranking, or in run position, as there isn't a second wire to the load side that gives full 12 volts.
Of course if the ballast resistor is jumpered, or bypassed the voltage will be the same all the way through. But did he say he had jumpered it and I missed that? And a ballast resistor that is bad usually goes open, or at least partially open, so has a higher resistance. My recent one that failed had 4.5v to the load side of the resistor when it failed.
And I didn't see where he said he had electronic ignition? He just said the ignition switch was replaced.
 

·
Registered
Joined
·
1,773 Posts
Since I've recently replaced my ballast resistor, and checked voltage at both sides, I know the output of the ballast resistor is not the same on both sides. And ignition voltage through it is the same cranking, or in run position, as there isn't a second wire to the load side that gives full 12 volts.
Of course if the ballast resistor is jumpered, or bypassed the voltage will be the same all the way through. But did he say he had jumpered it and I missed that?
And I didn't see where he said he had electronic ignition? He just said the ignition switch was replaced.
I didn't see it stated but evidently fixed (so far)---see post #13
 

·
Registered
🐔County, TN. 55 Bel Air Sport Coupe
Joined
·
10,620 Posts
Since I've recently replaced my ballast resistor, and checked voltage at both sides, I know the output of the ballast resistor is not the same on both sides. And ignition voltage through it is the same cranking, or in run position, as there isn't a second wire to the load side that gives full 12 volts.
Of course if the ballast resistor is jumpered, or bypassed the voltage will be the same all the way through. But did he say he had jumpered it and I missed that? And a ballast resistor that is bad usually goes open, or at least partially open, so has a higher resistance. My recent one that failed had 4.5v to the load side of the resistor when it failed.
And I didn't see where he said he had electronic ignition? He just said the ignition switch was replaced.

You say the "resistor" while I had written "coil". Still it's pretty easy to tell the difference if you have basic electrical knowledge.

The point is that unless there is a load on the circuit, a resistor (or a coil) DOES NOT lower the voltage. Not a single bit, not a millivolt. That's why I said " IF the points are open (or your electronic ignition isn't firing), then you should have the same voltage as the battery on BOTH sides of the coil." With the points open there will be no current and NO voltage drop.

If you don't understand this then you don't understand Ohms Law. It's probably the first thing they taught us in electronics and I'm told that it's one of the first things electrical school also.

Ohms law is the most basic thing that everything else electrical is based on. Electrical 101
 

·
Registered
Joined
·
7,723 Posts
If the ballast resistor is bad or a problem with its wiring, it will do exactly what I said. The ballast resistor is bypassed when cranking to give the coil full voltage when it needs it the most, while cranking which lowers the battery voltage.
Yes, it is loosing power in the run position, after letting the key loose. That is the run position. It has power in the start position which again is when the ballast resistor is being bypassed.
In case you forgot what you wrote, here it is above. You most certainly were talking about the ballast resistor.
 
1 - 20 of 30 Posts
Top