Re: Need Help w/R9 OD Control Unit

Posted by HH56 On 2010/6/16 16:25:14

If you haven't already, suggest downloading the service training manual on the econodrivehttps://www.packardinfo.com/xoops/html/downloads/EconoDriveTrainingBook.pdf There is a schematic and halfway decent description of the R-9 electrical operation.

Obviously, replacing or repairing the original relay assy would be preferred but if that's not practical, it MIGHT be able to be replaced with a pair of modern relays and keep the wiring intact. Actuating relay 1 could be substituted with another capable of carrying the current such as the Bosch and solenoid could be made to work similar to R11 --but 2 caveats.

In the current system, the pull in and hold in coil are both fed from terminal 4 when governor and other switch logic allows relay 1 or actuating relay to engage. The wire to hold in coil at relay is actually terminal 3 but that is fed internally from 4 by being in series with the second relay coil and means that relay also pulls in. It's function is in completing part of the ground out circuit and was eliminated in the R-11. The first kicker comes in determining whether the R-9 solenoid hold in coil could handle being hooked up directly to voltage without that second relay coil in series or if it would overheat. It should be possible to add a resistor if one of sufficient wattage and resistance to the original second relay coil can be easily found if it looks like that may be a problem.

The contact logic of the original assy could be bypassed and almost duplicated with a second Bosch relay. It's coil would be parallel to relay 1 so both actuate at the same time. (Two Bosch singles are much cheaper and easier to find than a DPDT relay with proper specs.) That second relay only uses the normally closed contact to control the ign ground out circuit in conjunction with mechanical contact in solenoid. That is the other kicker because it would have to be determined that mechanical contact stays open when solenoid is not energized since the open series contact in the original second relay is now gone. The R-ll runs the ground out circuit thru the kickdown switch instead of second relay to ensure it stays open when not in use. To do that on yours would require an R-11 switch and wiring changes.

The solenoid will determine if you can do something without using the original relay so the main question is electrical and if something you wish to pursue, could be investigated. I don't think the R-9 solenoid can be replaced with the later one but perhaps someone with both units can compare mounting and plunger length to answer that.