'50 shoebox overdrive question

Help guys - either this car has a gremlin in it, or it's just acting like a female car. The overdrive works just find as long as I don't use the headlights! I drove it Thur, Fri and today - OD operated just fine - then we go to a cruise-in tonite - had to turn on the headlights to go home and the OD won't in gage! Now I know the wiring in this car is crap and I'm replacing it a little as I go, but I don't get the connection here on this. Any ideas. Help - Thanks

 

Sounds like the solenoid isn't getting enough juice. Is it still 6 volt?

 

Yes, it's still 6 volts -

 

Here's the latest - as I'm am driving if I turn the lights off after a few minutes I can get the OD to in gage - when I turn the lights back on the OD won't in gage. Anybody got any ideas?

 

I had the same problem with mine..........I would love to know the answer.

 

Might sound silly do they share a common power lead or ground ??

also how old is the wiring ?

If possible just make a dedicated line for it

and the "connection you don't get " may be just that ,,damaged or really aged frail wiring will break down and carrry less current..

Had it happen with an electric fuel pump long ago

 

i put mine on a toggle switch. just hit the switch and let off the gas and it shifts. i hid the switch in the cigarette lighter since i dont smoke.

 

Poor input voltage and bad grounding.

I would definitely make wiring a #1 priority. If you are using the original wiring harness, you are just asking for a bonfire on cruise night. I would guess that the combination of oxidized wiring and rusty connections is taking your 6 volts down to just over 3-4, which can't engage the solenoid. Go buy some wire and connectors, use muriatic acid and a brush or naval jelly and get the rust off all the connectors (wash it off after you get the rust off), reconnect with a dielectric grease to keep everything rust free and use shrink wrap on the wiring to keep some of the crud out in the future. I would bet a dollar that cleaning up the connections and new copper wires would make it all happy again.

Oh, and if there is any question about how good your wiring is, grab a hold of a connector and bend the wire sharply back and forth. On my 52, all the old wire insulation just crumbled away and turned to charcoal in between my fingers. I live in a dry hot climate, but just imagine how hot and dry it gets under the hood...

 

Please explain how you wired it - what did you bypass - and so on

 

This might help

http://www.1956goldenhawk.com/manuals/overdriv.pdf

 

more info - the OD wiring has been updated - after driving with headlights on for about 15 minutes the OD won't work and the battery gauge shows a discharge. If I turn off the lights the OD works and the gauge shows charging. I've looked at the wiring diagrams and I can't see any connections with the OD and the lights. Any ideas??

 

Poor grounds usually cause weird problems!

 

Give it its own power source and ground

 

It sounds to me like a charging system problem. If the generator isn't putting out enough to keep the battery charged with the lights on then there is probably not enough battery power to keep the solenoid engaged.

I'd give the generator a tune up with new brushes and polish the commutator and probably a new voltage regulator. Clean the wire connections and grounds.

I think the OD problem is just a sign that the charging system is not up to snuff. I bet if you fix the charging system the OD problem will disappear.

 

I agree with Tommy. The solenoid has two windings; a pull in and a holding. Circuit is fused at relay on firewall for 30-amps; a lot of current. The pull-in winding takes a lot of current.

Here's the original wiring diagram for a Merc, should be the same:



Here's a sketch of a toggle switch install. If your governor is stiil good connect the ground wire shown on the solenoid to the one wire on the governor (It will then go to ground through the governor). If still 6-volt positive ground the From Battery wire needs to be a negative (-).




Jim

 

Tuning up the generator is a GOOD idea. Also check to see if the commutator has worn out of round - causes the brushes to float at higher speeds. (I found that problem on a hi mileage Delco back in the 60's.)

As suggested bad or dirty grounds is another place to look as well as the distributed corrosion thru the length of any of the wires in an old harness.

But before you go buy another V regulator (probably very hard to find) try burnishing the points just like you would in the distributor.


PS Back in 1957, I wired a 53 to have a 'kick-down' switch up on the end of the shift lever (got the idea from a guy who wired up Columbia rear controls that way). Allowed me to go in/out of 2nd kinda like an auto. At times, depending on traffic, it was very handy not to have to use the clutch.

 

Well I spent a good deal of time this morning going to each wire that was screwed or bolted down to relays, coil, regulators, etc and cleaned and sanded or filed. The test drive went well, so this afternoon I did some more. We went to our every Saturday nite cruise-in and the car performed perfect. Thanks to everyone who responsed - it's great to get on the Hamb board and get all this help!!

 

Congrats on your victory

 

BarneyO, what kind of switch did you use in the end of the shift lever?

 

There are no common connections between the headlights and the overdrive or at least there shouldn't be. I just made up a new wiring harness for the overdrive on my 49 and it now works perfect. If you do a google search on Borg Warner overdrives you will find a wealth of information. If you check the voltage at the Ign. terminal on the overdrive relay it should be 6 volts if you turn the headlights on it should stay at 6 volts. I would do this with the engine running. If the voltage drop is significant I would make a new wiring harness.