Boomer
Active Member
Thanks.
Wanted to reply to Mr C's post about electrical gremlins, as I have a few of those hiding in the car as well.
Electrical systems can appear very imposing and intimidating due to the sheer volume of 'stuff' involved. And there are certainly components and faults that are challenging to diagnose.
I would hazard a guess that 75% or more of electrical issues in our old cars are connection-related. As in, a poor connection. Of that figure, at least 50% would be bad ground connections. These are usually lugs under washers somewhere on the body or frame.
To oversimplify a bit, think of an AC light in your house: you have the power company source, wire running into your house, a switch, the light, and a return.
Now substitute a DC battery for the power source, and a ground connection for the return.
If you use a simple Digital Volt Meter (DVM) to check the voltage, you can check it before the switch to see if you have power coming to the circuit. If not, you'd go back to the source (battery) and check there.
If you have power at the switch, close the switch and check the other side. If yes, switch is good. If not, switch is bad.
On to the light socket, bulb good or bad. If good, check the physical condition of the socket proceed to ground connection.
As I said, it's an oversimplified explanation, but basically that's all there is to it. If you have good power and ground connections and you've got power coming to the component (switch, bulb, gauge, motor, etc) with no results, check the component.
When tackling an old car like this one that hasn't been in use for many years, I make it a practice to loosen and clean every ground connection I come across. Corrosion from years of moisture as well as electrolysis from dissimilar metals will break connections out of view under washers or in connectors, like those big firewall bulkhead plugs.
Two things worth having: a DVM with an audio feature for checking continuity between connections, and contact cleaner. The continuity 'beeeeep' is nice because it frees you up to keep an eye on your work and just listen for results. Hook the meter between two contacts of a switch, close the switch, you should get a beep. If not, the switch is the problem but not necessarily bad.
Contact cleaner is the other important thing for electrical work. I use a product called Caig DeOxit D5 aka Red which can clean light surface corrosion, grease, and other build up off contacts inside switches. WD-40 will work in a pinch. Squirt it in, work the switch, re-test. Same goes for those snap together connectors - pull them apart, spray a small amount in, the work the connector together and apart a few times to mechanically clean the contact areas.
Loosen those ground connections, spray, work back and forth a bit, then re-tighten.
95% or more of electrical problems are that simple. Tedious, sure. But it's a process of elimination: clean the contacts, check for voltage, isolate the problem component. Sometimes it's even a break in the wire hidden by the insulation. Those tend to be annoying since they're often somewhere in a harness.
Hope this helps you overcome those gremlins. Once you corner one and defeat it, you'll see how easy it really is. Time and patience are the bigger issues.
Wanted to reply to Mr C's post about electrical gremlins, as I have a few of those hiding in the car as well.
Electrical systems can appear very imposing and intimidating due to the sheer volume of 'stuff' involved. And there are certainly components and faults that are challenging to diagnose.
I would hazard a guess that 75% or more of electrical issues in our old cars are connection-related. As in, a poor connection. Of that figure, at least 50% would be bad ground connections. These are usually lugs under washers somewhere on the body or frame.
To oversimplify a bit, think of an AC light in your house: you have the power company source, wire running into your house, a switch, the light, and a return.
Now substitute a DC battery for the power source, and a ground connection for the return.
If you use a simple Digital Volt Meter (DVM) to check the voltage, you can check it before the switch to see if you have power coming to the circuit. If not, you'd go back to the source (battery) and check there.
If you have power at the switch, close the switch and check the other side. If yes, switch is good. If not, switch is bad.
On to the light socket, bulb good or bad. If good, check the physical condition of the socket proceed to ground connection.
As I said, it's an oversimplified explanation, but basically that's all there is to it. If you have good power and ground connections and you've got power coming to the component (switch, bulb, gauge, motor, etc) with no results, check the component.
When tackling an old car like this one that hasn't been in use for many years, I make it a practice to loosen and clean every ground connection I come across. Corrosion from years of moisture as well as electrolysis from dissimilar metals will break connections out of view under washers or in connectors, like those big firewall bulkhead plugs.
Two things worth having: a DVM with an audio feature for checking continuity between connections, and contact cleaner. The continuity 'beeeeep' is nice because it frees you up to keep an eye on your work and just listen for results. Hook the meter between two contacts of a switch, close the switch, you should get a beep. If not, the switch is the problem but not necessarily bad.
Contact cleaner is the other important thing for electrical work. I use a product called Caig DeOxit D5 aka Red which can clean light surface corrosion, grease, and other build up off contacts inside switches. WD-40 will work in a pinch. Squirt it in, work the switch, re-test. Same goes for those snap together connectors - pull them apart, spray a small amount in, the work the connector together and apart a few times to mechanically clean the contact areas.
Loosen those ground connections, spray, work back and forth a bit, then re-tighten.
95% or more of electrical problems are that simple. Tedious, sure. But it's a process of elimination: clean the contacts, check for voltage, isolate the problem component. Sometimes it's even a break in the wire hidden by the insulation. Those tend to be annoying since they're often somewhere in a harness.
Hope this helps you overcome those gremlins. Once you corner one and defeat it, you'll see how easy it really is. Time and patience are the bigger issues.
