Can't locate the starter relay on 1995 merc cougar. replaced starter ,ign. switch,but starter won't engage.

Is the anti-theft light lit on the instrument cluster ? Won't start how ? When you turn the key to start , what happens ? Nothing ? This would be a No crank - no start condition . Now if you turn the key to start and the starter engages and spins the engine and it doesn't start an run , this is a engine cranks no start condition ! Now which is your problem ?

There are two fuse's IGN A fuse 40amp and IGN E fuse 10amp ,both are located in the under hood fuse/relay box . Also there is starter relay located in the same under hood fuse /relay box . There also is a crank fuse 10amp in the under hood fuse box . Besides the fuse's and relay ,the ignition switch or the PNP - park neutral position switch could be bad . Testing the whole starter circuit should be done ! How to voltage drop test starter motor circuit

Check connection battery,could be starter.

might be a burned spot on the starter contacts where the brushes power the motor.
tap the starter to see if problem goes away.
sometimes you can clean the contacts but that is a temporary fix.

Just changed mine for the same problem!!! replaced starter, problem solved! Unusual design by american standard, for the main motor to continue to drive, !?

If I understand you right, the problem is the engine will not crank, that is turn over when you turn they ignition key to START. Having said that, might it be that the issue is with the starter system. The starter system is initiated at the ignition switch when the key is turned to start. At this point, the ignition switch then provides +12VDC to a starter relay (if the vehicle has got one) or direct to the starting solenoid. The relay is but a remote switch with slightly higher amperage capacity. The starter relay then engages and supplies +12VDC to the staring solenoid. The starting solenoid then performs two (2) functions. It provides the switching action (hundreds amps) from the battery heavy cable to the actual starter motor. The solenoid likewise pushes a small pinion gear along the shaft of the starter motor to engage the ring gear. The ring gear is of course on the edge of the flywheel which in turn is attached to the crankshaft.

Starter system problems could be corrected by:
1. check battery, battery cables and connections;
2. charge the battery if required;
3. clean brushes and guides of brush holders of the starter motor;
4. clean the commutator and commutator segments;
5. check/replace the armature or field coils if determined to be defective;
6. in some extreme cases it could be the drive pinion or the flywheel gear ring is defective.
7. often it is the big switch that the solenoid activates that looses contacts causing no +12V internally to the motor.
8. Most likely would be a defective starter relay or the IGN switch itself. Relative to this, you might try and check the connectors/terminals and electrical joints.

In the picture below, the upper portion is the starter solenoid while the one below it is the actual starter.

Given the amount of work to overhaul a starter, you might consider just replacing it.

So recommended course of action is determine if there is +12VDC at the starter solenoid when IGN switch is turned to START.

You've pretty much answered your own question, although I doubt it's demons...LOL. Ign switch, nuetral safety or park switch, shorted starter, could be chaffed wiring. If your in the ON position and the starter engages, I'd be looking at the ign wire from the switch to the starter solenoid and or relay. Your car is 20 years old so anything is possible at this point. Your best bet is to go to ALLDATA>COM and buy the wiring schematics for your car grab a DVM and start checking your circuits.

There is no "KILL" switch. something isnt hooked up correctly. or a relay is bad/ fuse? I hope the starter wasnt replaced for no reason? Be sure IGN A fuse is good,(under hood fuse box) CRANK fuse, (in dash fuse panel), STARTER RELAY (in under hood fuse box) , battery good? connections tight? shifter in PARK?

its on the driver side of the motor on the botton there no easy way to change it make sure u undo the battery

If the switch (neutral safety switch) is broken, it will not crank regardless whether you jump the battery or a new battery is installed. I don't have specific manual for your year that's why my advice is as in general. With a remote starter tool, bypassing the solenoid wire with remote starter which is connected to the positive terminal of the battery of it's other end. Once positive current flows from the battery, through the remote switch, flowing towards the solenoid, the starter should engage indicating a bad wiring harness connection from ignition switch. If it doesn't crank at all you may have a bad starter assembly and needs replacing. If your starter is clicking using it's own battery power, your battery is low of charge or your charging system is malfunctioning.

Pls, rate this suggestion, thank you.

2 problems, first you have bad starter or starter relay for starter staying engaged, keep alt plugged in has nothing to do with starter staying engauged, to test starter relay, jump at relay bat + post with red/bk wire on solonoid, if cranks over without staying engaged, then not relay or starter but rather in your ign switch, ford had bad problems with ign switch some years ago doing that