Joined: Thu Oct 27 2005, 04:58PM
Location: Australia
Posts: 411
I've got a SportFury grille for my '70 Fury III 'vert .. but I don't have any of the mechanism to operate it. Does anyone have a factory diagram of how it works so I can get an idea of what I'm trying to replicate?
At the moment I'm thinking electric motors with microswitches, etc ..
No diagram, but you need a motor, usually located on the center grille to radiator brace, it has a square rod that passes through it, and connects to the headlight doors. The motor has a wire that connects to the engine side bulkhead, and then to the headlight switch. Hope this helps. MPJ
I'm doing the same thing on my car. You need to buy the motor and the relay. The rest is wiring. The motor has open and close limit switches built in. You do need to get a motor from a full size Dodge or Plymouth in order to get the correct limit switch gear. The door travel, in degrees of rotation, is different for Charger, Fury and Imperial. The motors are the same, just the gear is different.
Joined: Tue Oct 11 2005, 01:33AM
Location: Calgary, Alberta
Posts: 5893
I also found this in my files - stolen from one of the boards.
Looking at the circuit and the way in which the motor is driven, a headlight switch failure can't damage the headlight motor. A relay failure is also very unlikely to cause motor failure unless the two wires from it to each motor get shorted together. That would make the motor endlessly cycle the doors open/closed when the ignition and or the headlights were turned on. Pretty well the only way the motor can over run the internal limit switches is if one of the limit switches fails to a switch closed condition. IE the contacts stick or a heavy load caused by binding door(s) caused the motor to draw heavier current and the contacts welded themselves together. More likely, the cam simply wore down enough that it hit the limit switch but failed to open the switch. There is BTW a circuit breaker on the power feed to the control relay that should protect against binding door loads. However, if the load is just under the breaker trigger point, over time the abnormal current could weld one of the door motor limit switches.
Headlight Motor 101
When you open the end of the door motor, you will see the two limit switches and a plastic gear, which also acts as a cam to trigger the limit switches. Note also, when one limit switch is triggered by the cam to open, the opposite limit switch will be closed. The motor has two field windings, one connected to one end of each limit switch. The two wires going from the motor to the relay are connect to the other side of the limit switches. As such if you apply power to one of these leads while it's associated limit switch is closed, the motor will run until the cam opens the limit switch contact. With no load on the motor, IE you've got it on the bench, the motor could "coast" past the now open limit switch and re-close the contacts. The motor would then start eating teeth on the plastic cam. So don't do that!
Because the plastic gear determines how long the motor runs to either open or close the headlight doors, different sized doors will use different size cams. This is where most people buying motors off eBay get into trouble. If you install a motor from a short travel headlight door into a longer travel door, the headlight doors will not open or close completely. If you do the reverse, the door will hit it's mechanical stops before the cam gets to the limit switch. The motor output shaft will stop prematurely while the motor is still turning. This will strip the plastic teeth on the cam drive.
Yes you can get replacement cams, but according to one source I read they are car specific and the replacement cams are color coded as follows:
Red - Plymouth's and Charger's Black or Green - Dodge Monaco White - Imperial's
What I'm not sure of is the effect of build year, unless for example all Plymouth's with headlight doors use identically sized door swings. Also, unfortunately I don't think the original motors were built with cams that followed this coding scheme.
I have two motors with white cams and I know neither came from an Imperial. One is marked as Mopar 2889247, it's not in my '70-71 Parts List, but I know it came from a 70 Sport Fury. It might be the right one or it might be a lucky replacement that either worked or didn't quite open or close the doors. The other motor came from a Charger but is most likely an after market replacement because it has no Mopar marking and has a strange looking 11 digit part number.
However, to further confuse things, the '70-71 Parts List says the following:
Code 8-34-278 Gear and Gasket Package 70 Charger, Chrysler and Imperial 3420922 70 Plymouth 3420910
Code 8-34-280 Motor, Rotating Headlamp 70-71 Charger, Chrysler and Imperial 3431438, 70-71 Plymouth 3431437
This grouping contradicts the color code grouping and there is no mention of Dodge so I assume none had hidden lights in 70-71. Don't know enough about Dodge to know for sure.
So, when swapping motors around you can't tell which type they are by just looking at them, you must know for sure what car they came from or better from their part number if you can find a listing. All bets are off for after market stuff.
There you have it, Headlight Motor 101 :rollin
In your case, most likely the cam has worn down to the point that in one position or the other, it doesn't completely open the limit switch and the motor kept running after the head light doors hit their stops. That would eat the plastic teeth. You need this kit - 1970 Plymouth - 3420910. Try a dealer, you just never know what's sitting on a shelf somewhere.
BTW, I don't see any good reason why you couldn't take any Mopar motor and put kit # 3420910 in it to convert it into a Plymouth motor.
Added by Darkrapid: Also as a note. I called my local Chrysler dealer. I have some friends their. They confermed that the 3420910 was superceded by 3837146. So I'll search for that one.