87 FX16 vibrating/rough idle

[Ladyfsh]

Once the car is completely warmed up, the vibration is pretty bad at a complete stop. It seems to be primarily focused up through the steering column. Because of age and suggestions from many others, all motor mounts were changed, we also increased the idle. Did the first 3 mounts and did not do the last one because the mount looked fine. The vibration improved, so we decided to do the last one. This has now made it even worse. Increasing the idle helped some, but when you add any load, it bogs down. Going from Park/Neutral to drive, it drops. Add in turning on the lights, it drops more. Turn the wipers on and drops even more. Tested the battery and alternator and both tested fine. Need suggestions.

[openflame06]

Considering when you turn certain things on that use power it makes the vibration worse I'd be looking for a short circuit somewhere. Or, i'm not sure how you tested the battery but the battery a lot of the time will start the car and seem fine but when load is increased begin to fail.

If the amps on the battery are low when the car is stopped I'd say its time for a new battery.