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Just bought a 55 Clipper Deluxe. Most of it is in pretty good shape but the engine is questionable. I noticed today that someone had actually installed the battery backwards (connected negative to ground when the car has a positive ground). Anyone have any ideas of what that might mess up? I mean, I'll find out soon enough once I repair some of the wiring but anyone's ideas will still help in troubleshooting (e.g. loose connection vs. blown fuse vs. got fried). Thanks in advance.

P.S. Loving the literature section!

If the car is otherwise stock, nothing is polarity sensitive so no damage will have been done.

If the radio has had the vibrator replaced with one of the modern solid state replacements that could have been damaged if the radio was on. The only other solid state replacement I am aware of that is available for a 55 would be the torsion level switch. It seems to be an unanswered question if the solid state switch replacements are polarity sensitive so damage there is unknown. Since you have a 55 Deluxe the car should have conventional springs so the switch would not be present. Any aftermarket items that could have been installed are also unknowns.

Many have switched the polarity on purpose in order to run modern electronics like a GPS or a phone charger that need negative ground to be able to power them using the cigar lighter sockets.

If it was switched on purpose, the two things that might need checking again on the Clipper would be make sure the wiring connection to the coil has the proper terminal going to ground -- If positive ground the + terminal would go to the distributor. The coil will work if wired backwards but the spark is better if wired correctly. Repolarizing the generator would also be needed if changed back to positive ground.

Well that is reassuring to hear. One of the previous owners clipped the spark plug wires and some other wires (presumably to make it harder to steal?) so I wouldn't be surprised if something is messed up in the ignition circuit because I tried to crank it yesterday (jumped off a full battery but hooked up backwards) and the starter motor did absolutely nothing so I probably gotta check the wiring to that. I do have the schematics. The cabin fan does not work, the radio also does not work but I doubt anyone has ever messed with it. Of note is that I've never checked the fuses, so.... As far as I'm aware the ignition circuitry is not even fused but it's a possible explanation for other things. And you're correct that the '55 C/D does not have TLR suspension. Let me know if you have any questions btw. :)

Edit: One thing is that there is (apparently) an interlock switch for the starter where you can only start in Park. Is it common for these switches to fail? Or is it very rarely a problem? If you happen to have a guess... I noticed that the back-up lamps don't light when I'm in reverse, but it could be some snipped wires again.

Also, someone spliced onto the battery ground and wire 17-Y in the schematic (off the resistor) but they now lead nowhere. Food for thought... no idea what that would be for.

Edit 2: It's to start the engine while in the hood. Didn't see the spice on the schematic before...


Edit 3: If anyone has a '55 or '56 C/D I would appreciate a picture of any wiring harnesses running thru the firewall, photo taken from the engine side of course. Someone snipped a bunch of mine and it would be very helpful as a cross-reference to the schematic.

The combination neutral safety - reverse switch is not a usual failure item in the electrical sense but it needs to be adjusted carefully. There is not an appreciable amount of slop or adjustment range so to have both the reverse and the start positions work at the correct spots takes careful positioning. Sometimes you need to split the difference when one position works and the other does not by trial and error. Position so the reverse lights work, then back off until they go out and then slowly back until they just turn on again. The actual detents for the Ultramatic positions is in the transmission and if there is slop or a loose lever in the detent assy (a possibility) or worn linkage it could affect the switch operation. I believe the 55 switch is round and located on the upper side of the steering column, engine side, and a few inches down from the firewall but could also be a rectangular sliding switch.

The 17-Y wire terminal on the resistor is fed off the IGN post on the ign switch and is frequently used to pick up power for something added under the hood if power is desired exclusively in the ign switch right or run position. It is not a very large wire so current draw can be a problem with items powered from there as too much draw will affect the voltage available for the coil. One common added item is an electric fuel pump although those are best added directly on the ign sw post on the dash side and separately fused. All the other switched power in underhood wires comes off the ACC post of the ign switch and is on in both the left or right positions..

You might carefully examine and clean the the fuse block under the dash. Even though fuses can look good, the fuseholders and wire terminals have been known to corrode or oxidize resulting in a poor connection.

Thanks for the helpful info! I'll write an update when I find out more.

So someone clipped the 4 wires on the backup/neutral switch (explains no starter / no backup lamps) and there were a few more that were chewed through by rodents. I didn't bother reattaching the wires to the switch because they aren't coming thru the firewall anyway. I just have a wire that I can touch to negative to run the starter, and fixed any rodent buffets I saw.

Problem now is that I realize the motor is locked up 😬. I took the spark plugs out (they were all not even screwed in all the way for some reason) and sprayed a bunch of PB Blaster into the cylinders. Didn't make a difference after a couple hours but I'll see after a few days and maybe I'll add some diesel or ATF too because I'm not sure the PB is gonna reach everywhere. I need to take a look at how to free up a locked up engine. For what it's worth, I took the valve covers off and everything looked okay in there. As a note, the engine oil is right at full and is a normal color (black from age).

If you have stuck pistons there is every chance you may also find some stuck valves. The rockers can look fine and everything appear well lubed while a few valves are completely frozen in the guides. Stuck valves can also lock up an engine and mimic stuck pistons -- although stuck valves, depending on how many or how far an engine needs to rotate before hitting one, do usually allow some movement of the crank. Once you get the pistons to move any valves that do not move will usually do a very good job in bending its pushrod and as I and several others on the forum have found out, the pushrods do bend quite easily.

It may require removing the heads or at least the springs so you can make sure no valves are stuck before you try turning the engine. Packard did have a special tool to remove springs without removing the head and that tool does not look too hard to bend or weld together -- although a home made version might not be as pretty as the Packard item. It is shown with instructions on how to use it starting on page 28 in this service counselor.packardinfo.com/xoops/html/downloads/SC/SC-VOL29NO5.pdf

Thank you for the great answers, do you think it's worth taking the valve covers off and shooting some PB Blaster down the pushrods in the meantime?

Pushrods pass thru fairly large holes and do not touch anything except on their end tips so not the problem. The valve stems rust in the guides and I doubt you will be able to get any substantial amount of penetrating oil down the small clearance between the stems and guides because of the springs etc that will prevent direct access.

Ah yes, that makes sense. Also I think I slightly misread your original response 🙃