Idle speed for fluid-drive cars

According to the shop manual,fluid-drive cars idle speed should be set at 450-475 R.P.M. for proper shift points.My question-does this mean in neutral,or in gear with the clutch out? Anyone? Anyone? Apologies to Ferris. Thanks,Bob.

My book gives the same speed (450-500) for manual trans or fluid drive. I take it this means neutral. I would set it to 500 in neutral and if you have a problem with stalling increase it a little.

Rusty-My problem is when idle speed is set low enough to shift,ammeter shows discharge at that R.P.M. Digital voltmeter shows 6.0 to 6.2 volts coming to batt.at that speed.Whats worse,when stopped at night with lights on ammeter shows discharge WAY down to mid point on ammeter,but jumps right back up to charge soon as I take off.Performed "Motoring Test" as described on page 238 in manual,and generator passed the test.Came out in morning to find batt.[6 volt Optima Red Top]too weak to start car.6.3-6.4volts comes to batt at anything above idle.Just doesn't seem enough to me.Am now disconnecting[-]side of batt.at night 'till problem is solved.Any ideas? 1953 Chrysler Windsor Deluxe with flathead 6.Thanks,Bob.

My 50 windsor did the same but I never had problems starting the next day so I would check the voltage regulator or complete electrical system for drain,sometimes driving at night I would manual shift it to keep the lights bright around town. Jeff

Bob...

STOP right where you are ! <img src="http://forums.aaca.org/images/graemlins/wink.gif" alt="" />

Your generator is functioning correctly !

This is NORMAL BEHAVIOR for all MoPars (or any other make) with a generator... they do not charge at idle speed.

As long as the ammeter needle swings to the "+" side of 0 when you accelerate, everything is behaving properly.

Set idle speed with gear-shift in neutral. No more than 450 RPM, if possible. If you engine is in good order, you shouldn't have trouble with stalling.

If for some reason it does tend to stall, increase the idle speed slowly, in 25 rpm increments... but try to keep it below 550 RPM.

As for your battery getting discharged, with the igntion "off" , and all doors closed, switches "off", remove the negative ( hot) terminal from the battery and connect an ammeter(capable of reading 1/2-amp increments) between the battery post and the cable just removed... if it indicates any sort of current draw, there is a gremlin in the system that is draining the battery.

Did you have the car running on a regular lead-acid 6-volt? If so, how did the chargin system behave ? Somes guys who have installed Optimas have experienced unusual charging system problems...

Also, if you're not running the vehicle fast enough to show "charge" on the ammeter, that too will draw-down the battery.

At any rate, the descroption of your "discharge at idle" scenario sounds like normal generator system behavior. This is one of the reasons that some folks who use their antiques extensively for parades ( lots of idling) swap in a 6-volt alternator, so that the battery gets charged, even when the engine is idling...

Some food for thought... let us know how you're making out...

<img src="http://forums.aaca.org/images/graemlins/cool.gif" alt="" />

Drive it more.

I agree with DeSoto Frank right down the line. Your car sounds OK to me. This kind of thing didn't occur when the cars were in everyday use because the battery stayed charged up. A slight discharge at idle didn't hurt anything because the battery quickly charged up once you got going.

If you can't drive more then get a 6 volt charger and leave it on the car overnight or possibly for several days. Don't overcharge it but if the battery charger is only charging an amp or 2, or if it is a trickle charger it won't hurt anything.

6 volt batteries are funny. It takes them a long time to discharge and a long time to charge up. Some years back I had a 1951 Chrysler. It took months for me to get it on the road. I thought I kept the battery charged up. But the first time I took it on the road, the generator showed a charge for the first 50 miles. I thought the regulator was overcharging but after an hour or so the ammeter settled down to the normal range.

Recently I bought a 51 DeSoto. The battery was low when I got it. I charged it up, it drew 4 or 5 amps for a couple of days, I thought the battery was shot. I would charge it overnight then let it rest for a couple of days. After a few weeks of occasional use and recharging, it only drew 1 amp. So I left it on charge for a few more days and it finally charged up all the way.

Having a fully charged battery makes quite a difference in starting.

If you don't have a 6 volt charger they turn up in thrift stores and yard sales. I have half a dozen I picked up that way, all for $5 or less.

There isn't much to go wrong with them and they are easy to fix.

You could even use a "wall wart" as a trickle charger. It wouldn't charge up very fast but you could leave it on all winter. A 7.2 volt would be perfect.

A clever fellow could connect a 7.2 volt wall wart to a cigarette lighter plug and just plug it in when the car was parked.

Hey, guys. Using my digital voltmeter, I hooked it up as Frank suggested and on the 2VDC scale, showed .188-.190. Not having an ammeter, I'm hoping this is the right way to test for current draw. If so, seems parasitic to me. Should I take a chance,and hook-up batt. again? Frank, nothing different after installing Optima batt. Least not that I could tell,'cept it looks kinda funny sittin' in that big 'ol battery tray. Thanks, Bob.

Frank, on the 6V alt---these work on positive ground?? How many amps do they turn out?? Do you use your old regulator? Just an update on the 52 also---all chrome in AZ, back by March---body all stripped and being painted--should be back in 2--4 weeks. The panels were all straight with just a few door dings---no rust except for two body mounts and some inner rocker stuff that I repaired last winter. Excellent for a 54 year old car. The test drive with the 3:25 gears showed at 50 on the speedo it is really doing 58-60 mph------life is good!!! 52er

On the alternator, its a Gm single wire 35 amp. Easy to mount on existing bracket with minor modification. No you do not require a regulator, but I would keep the genny and reg in a safe place just in case you want to return to pure stock someday. Any good auto electric can make a 6 volt positive ground alt from a GM single wire alt. In my area they do it for about a $100.00.......................Fred

Can you go with a more amp alt or isn`t it needed--lets say 65 amp?? What would be the wiring set-up for the alt. Would it affect any of the gagues. It has been a long time when I last converted to an alt set-up---I think I still used the bat wire from the reg to make it work. No exciter is needed??

You can get a modified GM-one-wire to put-out 6-volt Positive ground...

If you want to spend big-bucks ( like $700-$800 ), you can get a "Gen-r-nator" where then company takes your stock genny, guts it, and creates new alternator guts for the insides. Looks stock, works "better than stock".

Frankly, as I've been driving old six-volt iron for the last 25 years, I've done fine with the stock 6-volt generator system, as long as it's in working order.

Another easy test for any parasitic drains on your system: some night, when it's good and dark, remove the hot terminal from the battery, then just touch it back to the terminal post a few times... if you see a spark ( even a little one) each time you touch the cable to the post, there is a draw somewhere ( If you have a helper, have them observe the ammeter needle - if they see it deflecting each time to touch the cable to the post, there is indeed a draw)... might be the winding mechanism in the clock, but that usually stops after the first couple of jolts. If in doubt, diconnect to the power wire to the clock ( should be an inline fuse holder).

If there's still a draw with the clock out of the picture, then next thing I would check is the stoplight switch ( usually a hydraulic pressure switch), located either on the brake line somewhere on the left-front frame rail, or near the master cylinder. I've had stoplight switches go bad where they weren't "shorted" enough to light the brake lights, but enough to bleed-down the battery if the vehicle stood idle for about a week. The switch would feek warm to hot, if this were the case...

Again, disconnect a wire and see of the draw disappears.

The last "usual suspect" is a voltage regulator whose cut-out points are sticking closed, and allowing the battery to discharge through the generator; this is usually accompanied by the ammeter showing several amps discharge after the igntion is switched-off and the motor comes to rest.

You are right on the old system working fine if all components are up to snuff. I just like the idea of things working better---as a good constant charge to the battery and no dimming of the lights and such. Another reason is that you can get some newer headlights that are brighter than the stock ones. Annnnnd---my ole genny needs a rebuild, so why not upgrade to a better system---go 6V alt---plus when the car gets back from getting painted I have to finish the re-wire on the car---it seems like a good time to switch.