1940 Plymouth Business Coupe, P9 Roadking

[Bmartin]

Well, my car has finally arrived from exile and I can introduce myself.  It arrived this afternoon on Intercity lines.  They were great and got it to me in 10 days from scheduling.  Here are couple pics.

 

 

 

I found it on craigslist right by my parents, so I had them go pick it up for me and now she's finally here.  Its got a bunch of maintenance to catch up on, but it runs and drives and should be good for the big cruise next weekend. 

 

Now for my first question.  This is my first classic, so I am starting from scratch.  I've never even owned a carburated car before.  I've done quite a bit with modern cars, so it should just be getting familar with the technology.

 

The generator seems to be having issues, this is new since it left my parents, or at least it hadn't been noticed by them or the classic car mechanic who gave it the once over.  I started it up and something under the hood wass squealing like a stuck pig.  I think I've narrowed it down to the generator (all original 6V,BTW).  I pulled the belt off and moved the pulley, but its not obvious that the bearing is bad.  Put it back toghether and the noise comes and goes.  I did notice that the amp meter started jumping when the noise came back, then evened out when the noise went away.  Voltage seemed to be varying between 5.5 and 7.7 volts, depending on load.  This is my first amp meter in a car, it goes negative when the lights are on, but hovers at zero at all other times.  It jumped around zero volts when noisy.  

 

 

If you guys could school me on proper generator operation, that would be great.  The troubleshooting in the manual makes it sound like I need a amp meter and a DVM to properly diagose the charging circuit.  I've only got a DVM. 

 

So if I can find an alterator shop open tomorrow, will they be able to diagnose a bad bearing or just charging issues?

 

All help is greatly appreciated. 

 

Brian

 

 

Forgot to add, that generator got pretty darn hot!

Edited October 5, 2013 by Bmartin

[greg g]

Well in general the generator works or it doesn't,  The voltage regulator is the heart and brains of the system.  There are two oil cups on the generator one up front for the bearing, and one at the rear for the bushing, and the belts needs to be snug but not over tight.  When the engine is running the generator is making juice, by temporarily grounding the field post of the genny with a jumper wire it bypasses the regulator and the ammeter should peg at full charge at high idle.  If it does chances are the gen is operating.  The job of the regulator is to sense the load on the electrical system and the battery and through the cut out circuit, applies current to the field windings to produce power.  If the light is low and the battery is at full charge, the ammeter will usually ride at 0 or i the positive by like a needles width.  So the regulator will sense that and allow the gen to idle along, step on the brakes, and turn on the headlamps, and the reg will signal to start making juice.  So the amp gauge will pop over further to the positive to indicate the battery is getting recharged at a rate commensurate with the demand.  When you step on the brakes and turn on the head lamps the ammeter should go int on the negative by 15 or so amps.  It will also show a negative when you crank the starter, then the regulator will monitor the situation, and you should see the meter drop back down to a minimum charge rate after the current used to turn the starter is replaced.  The regulator has some adjustments that can be made and it also has contact points and electro magnets inside that do the magic.  The points could use a dressing with a points file especially if the car has been sitting for a while. 

 

The system in you car is positive ground, and as a 6 volt it s operation depends on clean and tight connections and properly sized wires and primary cables.  So you can start by oiling the gen, checking all the connections and making sure you have good thick primary cables not the wimpy 12v stuff.  You should pick up a service manual for your car before tearing into things if you can't find a brand specific manual, check your local library's reference section for th year appropriate MOTORS repair manual and study up on the charging system chapter, take a pile of dimes and copy the pages that apply to your car.  

 

So make sure your gen has oil, and the belt is in good condition and properly adjusted, before you do anything else.

[greg g]

Just saw the note about heat at the genny.  If the rear bushing is worn, they generally wear a bit oval. when the field coils are energized, they can pull the armature into contact with the coils.  This causes drag, which might make the belt squeal in time to the cut out circuit working, and heat from friction.  The bushings are generally available and fairly easy to replace.

 

Oh by the way nice car, welcome to the forum.

Edited October 5, 2013 by greg g

[Bmartin]

Greg, Thanks for the response. Sounds liks I need to pull the gen and disassemble for inspection. Ive got the factory manual with the expoded view. I'll tackle that in the morning as well as check for available replacements. Need it running next weekend. After that, I can take it down for while and go thru everything.

 

I was going through the manual and it did not mention an oil cups.  Will they be obvious in the disassembly?

Edited October 5, 2013 by Bmartin

[Don Coatney]

The noise is possibly from the drive belt or the rear bushing in the generator.

 

Remove the generator and carry it to a competent generator/starter repair shop. They can replace the rear bushing.

 

 

 

 

 

[1940plymouth]

Welcome to the forum and also congrats on your 1940 Plymouth coupe. 

 

The oil cups for the generator are visual at each end of the generator, I use 3 in 1 oil in mine.

 

I have had my 1940 P-10 Business coupe since 1988, not a show car by any means, but a driver.  They are a fun car to drive, again, congratulations and good luck with your coupe.

Bob

[RobertKB]

The noise is possibly from the drive belt or the rear bushing in the generator. Try this first. With the engine running carefully take a bar of bath soap and hold it on the "V" portion of the belt to coat the pully contact area of the belt. Use caution and keep your hand out of harms way.

 

 

I personally would not try this. One mistake when the engine is running could cost you some fingers or worse. The soap is a good idea though. With the engine off, put soap on the pulley contact area of the belt that you can easily get to. You can then move the belt by either loosening the generator and easily turning the belt or you can usually move the belt by pulling on the fan which will be a bit harder but can be done. If the latter way, make sure you have a good grip on the fan or you could lose fingernails when they scrape against the radiator when you lose your grip. Better to loosen the generator. There are also products out there that you can spray on your belt to quieten it. Your call.

[martybose]

It seems obvious, but I would check to make sure that someone didn't install a narrow belt in place of a wide belt.  It will sort of work, but the only part of the belt that would be working is the bottom, the sides wouldn't have any pressure on them.  Squeeling is what usually happens in this case.

 

Marty

[Bmartin]

Well, I tried the soap trick, no real change.  The generator was still noisy.  I took it for a ride and on the way back the amp meter went to full negative at some point and stayed there.  It was running OK when I pulled it in, but now it won't start, but does turn over slowly.  Battery is at 6 volts or so and drops to about 5.3 when trying to start it.  Is it a pheasable troubleshooting step to disconnect the generator and see if it starts? 

 

In looking at the wiring diagram, it does not seem that the generator shorting out would cause the amp meter to drop.  So I may be looking at a wire shorted out somewhere.  If there is a good thread already on here about electrical troubleshooting, please point me in that direction.  I'll be in the garage poking around. 

[Don Coatney]

I personally would not try this. One mistake when the engine is running could cost you some fingers or worse. The soap is a good idea though. With the engine off, put soap on the pulley contact area of the belt that you can easily get to. You can then move the belt by either loosening the generator and easily turning the belt or you can usually move the belt by pulling on the fan which will be a bit harder but can be done. If the latter way, make sure you have a good grip on the fan or you could lose fingernails when they scrape against the radiator when you lose your grip. Better to loosen the generator. There are also products out there that you can spray on your belt to quieten it. Your call.

KB;

You are correct this can be an unsafe act. Sometimes I forget that the things I did in the 50's (I was about 11-12 years old when an old mechanic taught me this soap trick) are not acceptable by the standards of today.

[RobertKB]

KB;

You are correct this can be an unsafe act. Sometimes I forget that the things I did in the 50's (I was about 11-12 years old when an old mechanic taught me this soap trick) are not acceptable by the standards of today.

 

Don, we were all 11 or 12 once. However, you must be really old! I wasn't 11 until the 60's, 1960 to be precise. LOL I still do dumb things today I know I shouldn't but hopefully less than when I was a kid. Still a kid at heart though.

Edited October 5, 2013 by RobertKB

[GlennCraven]

Congrats on getting the car into your possession and I hope you have great fun with it. Welcome to the forum!

[Bmartin]

Ok, here is the update.  I poked around a bit.  Then took the battery down to get it tested, just to be sure.  Its good, also picked up a 6 volt charger.  Came home and charged up the battery while I troubleshot.  Hooked the DVM between the pos and neg batter cables and had continuity - NOT GOOD.  Went through all the wiring and couldn't find anything, still shorted.  Read few articles and about common shorts - brake switch, voltage regulator, light dimmer switch.  Popped the cover off the regulator and pushed on the coils.  Then checked again and WALLA!  No continuity.  It fires up and runs and the amp meter sits just below zero.  Looking at the regulator, the top coil is showing some corrosion and its go about 50 miles on it.  So, here's my theory.  The faulty generator is damaging the voltage regulator.  Its almost definitely the rear bearing on the generator since I can squeeze the back and change the noise.  The bad news is that no gen places are open till monday. 

 

Thanks for all the help and the welcomes.  I'll keep posting up as I work through all the issues on this beast. 

Edited October 5, 2013 by Bmartin

[Floydflathead]

Look forward to seeing and hearing more about your car!  Sounds and looks like it's pretty much ready to roll (except for the generator).  I also have a 1940 Plymouth P9 coupe.  It is not as pretty as yours but is the original paint and upholstery.  Looks like someone went to put a radio in that car, and the dash seems to have been woodgrained a somewhat lighter color and possibly different pattern -- still your dash looks great!  Other Mopars I have are 1960 Dodge Dart Seneca, 1946 Dodge 3W business coupe, and 1942 DeSoto Custom club coupe.  Here's some pictures of those, though they aren't the best. The Dart was purchased new by my granddad and was his only new car.  The other Dodge and the DeSoto aren't currently running.  I'm working on the DeSoto actively to get it put back together.

[Bmartin]

Nice Mopars you got there.  Seems that I'm a closet mopar guy.  I pick my rides based on looks or capability.  I've got two out of four mopars and looking to make it three out of four.  Look forward to talking Mopars with everyone here.

[Don Coatney]

Don, we were all 11 or 12 once. However, you must be really old! I wasn't 11 until the 60's, 1960 to be precise. LOL I still do dumb things today I know I shouldn't but hopefully less than when I was a kid. Still a kid at heart though.

I am not that old. I just started fiddiling with cars at a young age. There was a gas station/repair shop next door and I would hang out there every day. The seasoned mechanic took a liking to me and taught me a lot. I was 11 in 1958.

 

Pictured is my dad in our driveway with the gas station behind him.

 

[Bmartin]

So, I need to locate a spare wheel and tire.  Anyone know the backspacing on the factory wheels?  Whats the best way to go about getting a spare?  New?  Junkyard?  other?

 

Thanks.

[Floydflathead]

You could even try calling a couple of reproduction parts suppliers because some of them sell used parts as well.  For example, Andy Bernbaum or Roberts Mopar parts.  Actually, these wheels are pretty common.  I collect/restore Hudsons as well and I think they are the same wheels on the contemporary cars.  Of course, the spare goes in the pocket behind the drivers seat in the 1940 busines coupe.

[greg g]

Some folks have been carrying the modern temp style from modern cars ad they are narrow back space is not an issue and they are dirt cheap at the pick and pulls yards.  Just match up your 5 x 4 1/2 bolt circle. 

[Plymouthy Adams]

I have a couple temp tires in a car or two Greg...quick and easy and I like to get the 16 size as they look quite at home in the trunk.. I also like to grab the modern scissors jacks..they are a bit safer in my opinion if you should ever need to change a tire along the road...they are also easy to hide behind the wheel and the spare mount...

[Bmartin]

Thanks for the info, that reminds me that I need a jack as well.  The temp spare is good in the meantime, but I eventually want to get a full sized spare for when I take a trip.  These tires are just too hard to find if I have an issue.  So if anyone knows the backspacing, that would be helpful.  I'll just pull a wheel later and measure it if not. 

[Plymouthy Adams]

Bmartin...the full size spare is great if you running stock rims and tires...but the wide alloys and fatter tires I have on the majority of my older cars..the wheel well is just not accommodating.to me the spare is just that..a temp tire to get you to the repair shop if on the road or to home if local area..odds of a spare being on the ground for any length of time is slim...I have my original jacks also cleaned up and freshened up in galvanize and black paint...they works great but will be a display item only....

[Bmartin]

Pretty sure its still got the stock wheels on it.  I think the tires are original size, but I would have to check.  Something like 6.00X16 Firestones.

[greg g]

I bought after market wheels from wheelvintiques.  they are 15 inch because I didn't want to deal with trying to find skinny 16's.  they are 5 inches wide with a 3.5 inch backspace. I believe 4 is max.  No fit issues.  And I am running run of the mill radials so I do not need to worry about replacements on road trips.  I first mounted 205 75's but they are a little short and threw the speedo off.  I have since put 215 75's on the rear and that corrected nearly all the speedo error. fitted up with trim rings and baby moons they still evoke a stock appearence.  my spare is a 5.60 15, 40 year old Goodyear I bought new, never been out of the trunk.

[Bmartin]

Thanks for the input, I'll have to dig into it a little more.  I've been tossing around the idea of some chrome wheels down the road.  So maybe the donut is the best route.  If anyone knows of cars with 16", 5X4.5" wheels, please post up.  It would save me some time running to different yards. 

 

Right now, I'm still waiting on my rebuilt generator. fingers crossed.  gonna start a new post with some questions on that.