Re: Bench Testing R-9 Overdrive Solenoid and Relay

Posted by HH56 On 2014/12/7 14:16:44

Depending on how many amps capacity your charger can output, it may or may not be adequate. My small 7 amp charger does not have enough output to energize the solenoid but once plunger is extended, it will hold it out. The OD is fused for 20 amps so I'm guessing it probably needs around 12- 15 amps for the pull in coil. I don't have a meter fast enough to measure the pull in current. You also need some fairly decent size wire for the test -- 14ga is a good average for testing. The factory used 12ga in operation.

If you have instructions on a 6v R11 solenoid, the R9 is very similar. The differences are in two terminals. The R11 has the pull in coil and hold in coil internally connected to the same terminal 4 and does not have terminal 3. The R9 has the coils separate so to test the R9, terminals 3 and 4 have to be connected together via a jumper wire. Case connects to ground and the jumpered 3 & 4 connection gets the voltage. If you don't connect 3 and 4 together the solenoid will "machine gun" since the pull in coil has a contact which opens just before the plunger is extended and will release the plunger. Without the hold in coil, the pull in and release cycle will continue. If the terminals are connected together and it still machine guns, the hold in coil is suspect. If it does not pull in and the voltage and amps is satisfactory for testing, then the pull in coil or the inernal disconnect contacts are suspect. The coil can burn open if something prevents the solenoid from extending the distance so the contacts can disconnect it. The contacts themselves are a service item and can be in fairly rough condition causing issues.

The other difference is in terminal 7 for the indicator light. The R11 does not have that terminal. On the R9, the contacts operate about at the same time. With the solenoid just sitting relaxed, 7 should be connected to case ground and 6 will be open. As the plunger is extended, at approx 3/4 or slightly more of the max distance out those terminals will switch. 7 will open to case ground to extinguish the indicator light and 6 will close to ground to enable the first part of grounding of the ignition cut out circuit. The R11 operates its terminal 6 the same but has no terminal 7.