Originally Posted by 52merc

Ford just buys their relays from OEMs like TE, Bosch, and others. As long as the aftermarket claims to be an exact replacement, I wouldn't worry about it.

The Passenger Compartment Fuse Panel only has the one relay, but there are several in the Power Distribution Box (underhood):

• Relay-1 = PCM
• Relay-2 = Starter
• Relay-3 = Blower Motor
• Relay-4 = Rear Window Defroster
• Relay-5 = Engine Cooling Fan High Speed
• Relay-7 = Run/Start
• Relay-8 = Fuel Pump
• Relay=10 = PCM (3.5L)
• Relay-23 = A/C Clutch
• Relay-37 = Trailer Tow Left Stop/Turn
• Relay-38 = Trailer Tow Right Stop/Turn
• Relay-40 = Engine Cooling Fan
• Relay-62 = Wiper Motor
• Relay-85 = Engine Cooling Fan Low Speed

You don't need to buy all new ones if you don't want to. Just buy a couple of each type. It looks like there is only 3-5 different types. Once You've swapped one out and it is not bad, you can re-install it and go on to the next one. You then have some spares if it is only one relay that is the problem. Don't rule out any of the relays. Who knows which one (if any) could be the problem.

Originally Posted by digitaltrucker

Thanks, I had printed out the fuse boxes and was going thru it. Appreciate your help and @1966tbird! Do you think or know if Relay testers are reliable?

Originally Posted by digitaltrucker

Regarding the passenger panel #49: This shows as a "relay" and in the owners manual under the section of "fuse amp rating" it states "relay. When I research this some places indicate a 40 amp or a 20 amp? So since the owners manual does not list an amperage my question is: Should I look for one that has no amperage rating? Or just use a 40 amp?

Originally Posted by digitaltrucker

So I tested all of the relays, all tested good! In reality, relays are either good or bad I guess because all tested good. No way to tell if it is weak. SO I ordered some known good ones and will begin the process to swap them out, in case there is a weak one.

Originally Posted by 52merc

If it is a relay that is the issue, it is not that it is "weak". It is because it has a short to ground which pulls the voltage down. The short would be from the main circuit contacts to the solenoid ground.

"Weak" to me infers that the solenoid will not shift the contacts (no click when you power the solenoid).

During all of this, have you always had the A/C on? If so, what happens if you turn the A/C off?

Originally Posted by digitaltrucker

Thanks!! OK that makes sense. I will do the change out mambo! LOL! Yes, the first time it happened I turned the AC off/on, which changed nothing rough idle remained until it went away and AC started cooling again.

Originally Posted by 52merc

How old is your starter? I'm thinking about ways the battery voltage can get pulled down by a large current draw. If the starter solenoid (the one right on the starter) is not disengaging completely, then it could still be drawing current, but mybe not enough to engage the Bendix and rotate the starter. There could also be some sort of internal issue with that solenoid causing it to partially short to ground. That is what I would look at next if the relays are all good.