OVERDRIVE QUESTIONS

TOM-WA-

I HAVE A 3 SPEED DUAL LEVER WITH OVERDRIVE

EVERYTHING WAS WORKING FINE AND ALL OF A SUDDEN THE OVERDRIVE WILL NOT KICK DOWN WHEN I PUSH THE GAS
PEDAL TO THE FLOOR....ANY IDEAS WHAT TO LOOK FOR AND HOW TO BEGIN TO TROUBLE SHOOT?

MY THROTTLE SWITCH LOOKS NOTHING LIKE THE ONE IN THE OVERDRIVE SERVICE MANUAL..I HAVE 4 WIRES AND CONTACTS THAT ATTACH TO IT RATHER THAN TWO

DocHornet

Yes, it SHOULD have 4 wires on the gas pedal switch. You can buy a brand new identical one from NAPA P/n ECHOD6284 for $26 (I just bought one for a spare.. Napa Online).

Basically, when you hit the kickdown, one pair of contacts of that switch disconnects the ground side to the overdrive solenoid, effectively disabling it. The other pair of contacts momentarily grounds the coil to interrupt engine thrust for a split second, to allow the overdrive solenoid to retract.

Since the switch is physical contacts, it seems unlikely that the connection to the solenoid is the culprit (the only way I could see that would be if the ground wire going from the kickdown switch back to the solenoid has a short somewhere along the way, and is maintaining ground contact, even when interrupted at the kickdown switch.

The other possibility could be a broken wire going from the kickdown switch to the coil (it will be attached to the same side of the coil as the distributor lead), OR, the contacts inside the switch are bad, not allowing the ground interrupt to occur.

I've attached the wiring diagram for the overdrive circuitry. The kickdown switch is detailed in upper LH corner of the diagram. Note that it calls for the 4-pin kickdown switch regardless of your tranny being double lever or single lever.

Hope this helps

TOM-WA-

DOC:

Thanks so much..just what i was looking for..Strange that the wiring diagram in the Hudson Overdrive Service Information manual is very much different from the diagram you sent me

Park_W

Check the date on that Svc Info, Tom. The wiring was changed for 1950 and later. The latter series systems used a different and more simple relay, and the solenoid and kickdown switch are different from '41-'49 ('48-'49 solenoid will fit on the later OD's, but the wiring is different).