Headlights, dashboard light flickering, car stalled.

[The "A" Team]

Hi everyone,

I ran into a couple of problems recently. When I first started my coupe, it started and ran fine, but a couple of hours later that night when I went to start it, nothing happened when I pushed the starter, but after a couple of tries it finally spun and started right up. Then, as I was driving home, I noticed the headlights and dash light starting to flicker and at one point, they turned off and the car stalled. I was able to start it again, but I noticed the lights flickering a little a again a few times before I got home. I wouldn't think it's a battery issue if the car is already started, and when I checked the battery before and after the car is started is reads over 6 volts and between 7 and 8 volts when running.

I thought it could be a case of old wires, especially when I saw some insulation missing on the windshield wiper wire (I disconnected that wire and will replace it at a later time), so I bought new terminal to dash wires, terminal to cutout wires, new distributor to coil wire, and to be safe, a new ignition coil.

I got the new items and started replacing them. A couple of things I noticed that could've been a problem:

Looking at the wiring diagram for the dash wires, it shows the ignition switch wire goes to the positive terminal on the coil, but when I took off the old coil, the ignition switch wire was attached to the negative terminal. I'm not sure which way is correct.

The piece of plastic at the base of one of the ammeter terminals looks like it melted. Also, I wanted to check if I wired the ammeter correctly since I don't see a + or - on the back terminals, but at first when I switched on the battery and honked the horn and turned on the lights, there was no movement of the needle either left or right. It also didn't go to zero and stays around 2 amps when the battery is switched off. It looked like I reversed the terminal wiring and when I switched them the needle did move to discharge when turning on the lights and honking the horn, but it still sits at around 2 amps even after the battery is switched off at the cutoff.

I just wanted to make sure what I'm doing is correct. I attached as many pics as I could.

Thanks.

John

 

[Y-Blockhead]

The first thing I check when I have any kind of electrical problem is GROUNDS. Make sure all ground wires are clean and tight, including the battery connections.

On the coil, if you have positive ground, wire so + side of coil is to points.

 

[The "A" Team]

The first thing I check when I have any kind of electrical problem is GROUNDS. Make sure all ground wires are clean and tight, including the battery connections.

On the coil, if you have positive ground, wire so + side of coil is to points.

Sorry, I forgot to mention, I checked and cleaned up the battery terminals and connections and also took the positive ground cable off the frame, cleaned it up and even sanded any corrosion down to the bare metal on the cable and frame to make sure it gets a a good connection.

The ignition coil was originally wired so the positive was connected to the terminal box and the negative was connected to the ignition switch, but the diagram that came with the new one shows the opposite. I'm not sure which part of the terminal box would go to the points.

 

[Y-Blockhead]

If you have stock wiring, The RED wire from the + side of the coil goes to the ignition switch. The other terminal on the ignition switch goes to the points. Your diagram does not show the second wire. Do you still have the armored cable?

 

[Bob C]

Be sure you replace the melted insulator before you hook up the battery.

 

[The "A" Team]

If you have stock wiring, The RED wire from the + side of the coil goes to the ignition switch. The other terminal on the ignition switch goes to the points. Your diagram does not show the second wire. Do you still have the armored cable?

I think the diagram shows the second wires from the ignition coil going to the terminal box.

The big armored cable that goes to the distributor is still there.

 

[The "A" Team]

Be sure you replace the melted insulator before you hook up the battery.

Do I have to get a special insulator part, or can I use something else, like a plastic spacer or something like that?

 

[oldman - NorCal]

First things first........... Install a starter mounted fuse to prevent an electrical fire as you sort through these issues. Don't ask me how I know...........

 

[The "A" Team]

First things first........... Install a starter mounted fuse to prevent an electrical fire as you sort through these issues. Don't ask me how I know...........

Already did that.

 

[nkaminar]

There are so many issues with the wiring on this car that you may want to get a new wiring harness and ammeter and start over. Every connection has to be bright and shinny and tight and not melted. The coil connection depends on how the battery is installed and whether the original style ignition switch is used or a modern ignition switch is installed and the wiring changed. Buy a polarity tested, see https://www.snydersantiqueauto.com/content/Snyders/Product_PDFs/A-12116.pdf

If you are electrically challenged, find someone to help.

 

[German guy]

I recently shifted my ground wire from the frame to the bell housing. I had been at the verge of purchasing all of the parts needed to convert to 12V due to balky starting power. The improvement made by the change to the bell housing was like night and day regarding starts. Starts every time immediately now. No more of that slow grinding of the starter. Also...I had the transmission down to locate a missing bolt from the bendix...YES I tried the magnet method. Had my mechanic do it and he found THREE bedix bolts lodged at various locations in the trans. Clearly my car eats bendix for breakfast. I shifted to the new version bendix that has no exposed bolts. That process gave me the idea to try the bell housing for ground.



I have only owned my '30 Tudor for 10 months but rather than replacing wires one at a time as I noticed insulation gaps...and the occasional spark....I wish that I had just bought a new harness and rewired the entire car from the start. Between ancient wires and poor previous restoration work you just don't know what you have unless you do it yourself. I am gong to strip every wire out of the car and start fresh this winter.

 

[Badpuppy]

I think the diagram shows the second wires from the ignition coil going to the terminal box.

The big armored cable that goes to the distributor is still there.

As Y-Blockhead said, the red wire connects the ignition switch to the + terminal of the coil, bypasses the junction box posts. The black wire you circled is between the - terminal and the left/driver side post. Yellow battery wire connects to the right/passenger side post and continues to the right side ammeter post. The yellow-black generator wire connects to the left post at the JB and then to the left ammeter post. You have a couple wires from the JB above the loom that don't belong there. You also need the clip that screws into the firewall to secure the loom. Same clip as on the left side of the engine. And find a new ammeter. It may be possible to repair, but probably not worth the trouble.

 

[Y-Blockhead]

I think the diagram shows the second wires from the ignition coil going to the terminal box.

The big armored cable that goes to the distributor is still there.

I was referring to the second wire from the switch, not the coil. Your diagram isn't showing the complete circuit.

 

[rotorwrench]

A lot of the modern reproduction ammeters are crap and don't have near the sensitivity of the old original ammeters. If it has any signs of melting then it got too hot and is likely not going to function. The heat can come from any loose connection in the system. The lights flickering tend to be problems with the wire at the generator to the light switch or the switch itself since that is the power connection but it depends on the condition of the battery and whether the engine is running or not. Battery power flows through the ammeter to all loads but the starter when engine is off. This is also if the ignition is connected per the mid 1929 service bulletin. The battery has to have a good connection to the system at all times or the generator starts to over-amp. The ammeter being compromised with the melt going on can start to isolate the battery from the system which just makes things worse.

A good wire with continuity through it is good to go. A wire with high resistance or deteriorated insulation is compromised and should be repaired or replaced. It all may have started with a loose connection at the ammeter. The ammeter has a charge side and a discharge side relative to looking at the front of the meter. The terminals on the back correspond to the two individual sides. The battery is connected to the charge side since it takes the charge. The generator is connected to the discharge side since it does the charging when functioning normally. The loads, with the exception of the starter, are all connected to the generator side of the terminal box or ammeter in the case of the dash light. The use of the plastic finger nuts on the ammeter is not always a good way to tighten them. They really need either a very good lock washer or a hex nut with a lock washer to get more positive grip.

As far as the starter not operating with the push of the foot switch, then I'd check the connection to the battery or check the foot switch for problems. The battery has enough capacity to function the starter as long as it's in good condition and the circuit is not compromised. The exception is if the starter is compromised in some way.