3-speed w/overdrive fuse

[Cecil/WV]

Originally Posted by 35fordtn

My 50 had a overdrive relay go bad and they are hard to find.. I have several friends who also had this problem

Vanpelt has them new!

[Blu Dice]

Problem I'm having - OD works fine until I have to turn on the lights. Then OD doesn't work, amp gauge shows discharge at slow speeds - so I think this keeps the OD from engages.
Thoughts?

[rotorwrench]

The 6-volt electrical system was taxed when current draw is high. If you have some crusty ground paths in your lighting circuit, this will tax it even further. Same with the overdrive and any other circuits that are in the under hood or under car environment.

[Blu Dice]

What should I watch for as far as the generator output is concern - electrical system is NOT my strong area.

[rotorwrench]

Output on nearly all pre 55 6-volt systems is only 35 amps. The genny will keep that up if the belt doesn't slip and the unit is in fairly good condition but the only time it has high current draw is when you have a lot of electrical components turned on at the same time or right after starting the engine. The battery has to be fully charged and in good condition with a good 6-volt reading on a volt meter. The electrical wire has to be well insulated with no visible corrosion. The return path from a headlamp bucket for example, should be clean and corrosion free in the socket to bucket connection and in the bolt up of the bucket to the fender. The fender connection to the body has to be clean & tight as well to get a good return path to the frame and back to the positive cable of the battery on positive ground systems. All other circuits need the same continuity for the system to function normally.

[Blu Dice]

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Does anyone have or know how to bypass the solenoid with a switch to activate manually?

[Mike51Merc]

Originally Posted by Blu Dice

Does anyone have or know how to bypass the solenoid with a switch to activate manually?

I had a similar OD problem that plagued me for a couple of years. My OD occasionally wouldn't engage at night (usually on my way home from a cruise night). With the headlights on, after driving in slow traffic for a while, I'd hit the highway and it wouldn't upshift.

After a lot of troubleshooting, I found that the OD relay was suffering from a voltage drop, and I found that the solenoid is very sensitive to voltage drops and won't engage at less than 6V (which makes matters worse because the solenoid is TRYING to engage and sucking up a lot of current while trying). Turns out that when I rewired the car, I used 14 gauge wire to feed the relay. Upgraded to 10 gauge wire--- problem solved.

As for a "manual override" switch, the Batt lug at the voltage regulator is fed with a large wire and is right near the OD relay. You can run a jumper between them with alligator clips, or you can wire a toggle switch to your dash from there (be sure to use heavy wire).

[Blu Dice]

Originally Posted by Mike51Merc

I had a similar OD problem that plagued me for a couple of years. My OD occasionally wouldn't engage at night (usually on my way home from a cruise night). With the headlights on, after driving in slow traffic for a while, I'd hit the highway and it wouldn't upshift.

After a lot of troubleshooting, I found that the OD relay was suffering from a voltage drop, and I found that the solenoid is very sensitive to voltage drops and won't engage at less than 6V (which makes matters worse because the solenoid is TRYING to engage and sucking up a lot of current while trying). Turns out that when I rewired the car, I used 14 gauge wire to feed the relay. Upgraded to 10 gauge wire--- problem solved.

As for a "manual override" switch, the Batt lug at the voltage regulator is fed with a large wire and is right near the OD relay. You can run a jumper between them with alligator clips, or you can wire a toggle switch to your dash from there (be sure to use heavy wire).

That's how my acts sometimes, but when I rewired the car I used a "original" wiring kit from Mac's - so I assume it's all correct gauge wire. The "feed" wire to the relay you mention- which one is this?
I'm lost as to how to run a jumper wire - a little more detail please - sorry I'm pretty weak in the electrical area -thanks.

[Mike51Merc]

Originally Posted by Blu Dice

That's how my acts sometimes, but when I rewired the car I used a "original" wiring kit from Mac's - so I assume it's all correct gauge wire. The "feed" wire to the relay you mention- which one is this?
I'm lost as to how to run a jumper wire - a little more detail please - sorry I'm pretty weak in the electrical area -thanks.

The feed wire is the wire that runs from the ignition coil to the OD relay. It supplys the power to the relay, which then sends the power to the OD solenoid. I bought new wires from Macs too, but didn't get one of those in the kit, so I made my own.

Even with new wires, you still should check for a voltage drop. You need a voltmeter (or what's called a "Multimeter"). Check voltage across battery terminals, then check voltage at OD relay.

A Jumper Wire is a temporary connection. Just a piece of wire with an alligator clip on each end.

[Blu Dice]

Thanks Mike