Recent purchase 66 l79 coupe. Had MSD 6AL box and points in dizzy. The coil had an array of wire spades with an insulating piece of plastic. I think the intention was to be able to switch if MSD failed. I removed MSD box and wiring and was using a 67 300 hp car as comparison to hookup wiring. On car with MSD the ballast resistor was bypassed ( both wires on same lug of resistor) both were red or pink and a smaller gage than wires on the 67. Does it matter what side the wires go on the ballast? And do you need the capacitor that is on the wire loom?

 

No. The ballast resistor is not polarity sensitive.

 

The resistor doesn't care which end is input and which is out. The capacitor on the coil is for radio noise suppression and needed only for AM with the original radio. The capacitor on the point plate under the cap is the only one needed. There is also a capacitor on the voltage regulator for radio noise suppression.
Smarter guys may correct me if I am wrong.
Ron

 

You seem to be correct on the voltage regulator and coil capacitors based on my less than original car.

 

There is also one on the heater blower for radio noise suppression, in addition to the half dozen or more behind the dash. I disconnect them as I only listen to FM on an aftermarket radio. The capacitors behind the dash were the old paper type and were falling apart allowing the leads to flop around with a potential to short out to the Z-bar. Of course I don't have a NCRS gold racer, just a driver. If you disconnect the capacitors with flag connectors, you have to readjust, tighten up, the female terminals to fit tightly on the male lugs. IF they don't fit tight, you can get intermittent contact and have to chase that down. PIA, but some are not fused .
I am envious of your engine compartment, but too lazy to try to match it!
Ron

 

My car was originally a no-radio option car but a previous owner had installed one in it. When I restored it I remounted the antenna in the correct place and went through adding a whole bunch of factory capacitors under dash and in the engine compartment. I don’t even remember where some of them are. I haven’t had the radio on in probably 10 years or more.

 

You might want to power up the radio occasionally as the electronics seem to fail if left unused for long periods of time. I can't remember which of the members here advised this, but I believe it is true as the radio in the 68RS quit working after many years of non-use. Maybe Jim or Dan can confirm this.

 

The electrolytic capacitor is the issue, especially when they are old and exposed to all kinds of temps. These are so named because they use a special compound on one electrode and employ a paste, or something short of a solid in their construction which gives them a lot of capacity for their size. They lend themselves well in radio and TV given the various filtering and coupling tasks they have there.

Over time the electrolytic capacitor dries out and shorts or goes open. An antique radio or TV that lights up but will not play is almost always going to be electrolytic cap failure rather than tubes. radio tubes, especially in cars last a long, long time. It's the electrolytic caps that go bad and replacing all of them is what radio restorers call "re-capping." There is anecdotal evidence that using a radio as opposed to leaving it to sit indefinitely preserves the capacitors but I have not had a satisfactory explanation from those smarter than I. That's an invitation for Mr. Lockwood to weigh in.

Why not replace the electrolytic caps with modern film capacitors? Because in film the same values would be physically far larger in size.

Dan

 

Why are you ditching the MSD box?
When you use that, the points are retained, but they are only a trigger, no need to set gap or dwell.

 

As Dan intimates, one of my other hobbies (besides working on FI) is repairing and using old radios.

Those fragile looking glass envelope vacuum tubes really are durable little things and electrolytic capacitors really do fail from age and lack of use. Dan you don't need my validation of this; you are spot on.

There are other parts in old radios which are notorious for going bad:

Carbon composition resistors, common in old radios, will drift up in value and that will degrade a circuit which otherwise sorta seems to work. Fortunately, you can use an Ohmmeter to measure the resistors and spot the ones which are out of spec.

Paper capacitors, like those used to suppress noise from the brake light switch and in other places under the dash, become leaky. They begin functioning more like high value resistors than actual capacitors. Best practice is to shotgun them all. Don't even worry about testing them.

Ditto for a type of capacitor known as a "postage stamp mica", so named for its rectangular shape and thin profile. Visually, these have their values color coded in an array of dots on one surface. Shotgun them.

Of course, also check the vacuum tubes on the tube tester at your local drug store. Tubes do fail. But just know that the other components are much more likely to be the cause of an in-op radio.

More often than not, an old radio can be brought back to near perfect working condition by simply checking/replacing the components Dan mentioned and the additional ones I just described.

 

Come on Jim, I haven't seen a tube tester at the local drug store in near on half a century.
I took a B&H TV repair course back in 1972 and built our first Heathkit color TV along with a scope and multimeter. Then the age of the throw away electronics came and put an end to my part-time career and most of my knowledge it seems.
Haven't seen a soda fountain at at the local drug store since the 1960s. Didn't Woolworth have one?
Ron

 

More than anything, I haven’t turned it on in a long time as the volume rheostat is dirty and squeals loudly and I’ve been too busy on other things to take it out and clean it good. But I hear you. I’ll try to put that on my schedule to do. Not that I can hear it much over the sidepipes.

 

Jim,
Boy, did that line bring back memories. I dabbled in tearing down old radios and amplifiers as a kid, and clearly remember going to the Sun Rexall Drugstore to use their tube tester. De-soldering old radio chassis and testing/saving resistors and capacitors. Great memories!!

 

While it might be slightly out of your way, Ron, I recommend a visit to Kempson Rexall Drug Store in Inman SC. They still have their soda fountain. In fact it was recently featured on 60 minutes (or maybe it was on Sunday Morning).

For all I know they also have a tube tester.

 

Kinda circling back to what Dan and others wrote.... I regularly use my old tube type radios. Almost all of them retain their 60+ year old electrolytic capacitors because they see regular use. Most of my old radios have many of their original vacuum tubes also. It's the typical "use it or lose it" situation.

Of course YMMV....

 

I play with old CBs and ham radios (e.g., Johnson White Face) once every blue moon. The boss' eyes lit up when I said I was looking for a vibrator. Needless to say she was disappointed when I pulled one out.