Packard Forum Index » V-8 (1955-56)

It is listed as a solenoid relay with no mention of it being solid state (I will inquire) and note that it is a bit large at 5.3 x 3.6 x 3.2 inches. I pointed it out simply as one of the possible options to simplify the project but possibly there are smaller, less powerful versions.

It is a relay and I was correcting my earlier post when you were doing your last one. Some of the SS relays are configured similarly and without looking too hard had assumed since you had wanted solid state you had found one.

Because of the large size, I am still leaning toward the inexpensive Bosch type relays. I believe a circuit like this would do the job nicely. Mount them in a dual socket for about the same price as the motor relay. If one did fail it is easy enough to unplug and replace one relay without having to buy the whole assy.

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yap,hh

that was thought too, use a socket,

What load do you think the relay would have to carry and do you suppose it could be done using a single DPDT non-latching relay?

Don Pierson Quote:

I don't know, but empirically I can tell you that running the full current through the switch is a bad design! I had to disassemble the 4-switch in my Pat and clean all the contacts because there is no relay in the loop and some of the contacts were burned. I had a similar problem on a 1979 Trans Am Firebird I restored and had to do the same thing.

The relays & aftermarket power windows setup on my 55 Pat has been installed since June 2014 and hasn't hiccuped yet.

Craig

I'm a fan of the Bosch style 12v relays. Awhile back I bought a lot of 15 of them off of eBay for like $12. The ones I got are rated at 30amps.

I plan on using some of them for my A/C controls.

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No idea what the normal current is without measuring but I'd guess 10-15amps. If the motor is stalled as when a window is max up or down and switch is held it can be a fair amount higher. A dirty or unlubed mechanism can also increase current over the clean and lubed unit. The circuit breaker is rated at 40 amps which is probably worst case if more than one motor was operating or stalled at a time. To my mind, even though it should never be close to carrying that amount the relays should be rated preferably 40amps in case of a short. 30amp relays are common with a rated surge of 40 so should be adequate.

I don't know of any readily available mechanical relays with a "neutral" position where no output is connected. Ordinary relay contacts are either N.O. or N.C in their relaxed state so in order to use a single DPDT relay there would have to be a state where there is a neutral so the motor could be off. There may be some kind of dual coil spring centered special purpose relays where this is done but I have no idea what they would be called or where to find one. Price would probably be considerable.

The name of the fellow in the midwest who was turning brass bearings for the window motors was Bob Aller. I just saw his name mentioned in another post.

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That's very true but keep in mind that in this case the relays will not help to take away any load from the switches. The full load will still be going through the switches and the relay is used only to reverse the polarity at the motor.

Not so. In Packards the full power is brought out to each switch for the original motor power. With the addition of relays a wire tap tee connection will be made in that power wire to additionally supply the relay contacts with power. The power will still feed the switch but once the relays are in the circuit all the switch will have is the tiny load of energizing a relay coil. The relay contacts will take the full load of the motor as well as reverse the direction.