Unpredictable Starting Behavior - 89 Taurus Options

[JimboJim]

Hello All: I need your collective thoughtful advice. I have an 89 Taurus wagon with the 3.8 engine. This is a one owner (me) car which I bought new in April of '89. It has 66K miles on it - has always been garaged & the original paint still looks like new. Here of late it has been exhibiting quite unpredictable & frustrating starting behavior. Some times when I twist the key to "START", there is no response from the starter at all. At other times, the engine starts & the starter "hangs" (i.e keeps running). At other times, the engine starts absolutely normally. At all these times, the dash lights come on as you would expect as the key is turned toward "START". The battery is good (rated at 675 CCA - tests out at 710 CCA). I have put two (2) new starter solenoids on it - the unpredictable starting behavior is demonstrated with both solenoids. The car has a new starter on it. The exterior ignition switch (where the key is inserted) turns freely & doesn't have excessive "play" in it - I have puffed a bit of graphite into it every year or so throughout the car's life. I have even run a solid ground wire from the solenoid to the engine block just to make absolutely certain that the starter solenoid had an unquestionably solid ground. I have always loved driving this car - but with this unpredictable starting behavior - I'm afraid of being left stranded if I go anywhere in it. This car has never exhibited any other electrical misbehavior whatsoever over the past 20+ years. Do any of you out there have any ideas or suggestions? Thanks. Jim O'Conner

[Crew Chief]

I dont know how many solenoids I have replaced and never did solve the problem. Fords require a full 12.4 + volts at the starter read this
http://www.greenflagauto.com/forum/search....te=voltage+drop

Do a voltage drop test across the battery terminals and the battery cables from the battery to solenoid and solenoid to starter repeat on negative side. I assume you have cleaned the battery cables but because of the voltage requirements they must be almost pristine clean so recheck them check the cables for bad spots insulation bubbling or any other sighs of corrision. If all of this checks OK then replace the ignition switch. Not the key but the electrical part, I suspect this is your problem but I would check the other items first as there is a chance they are your problem and all it will take is time to check them. The switch is quite easy to replace.

[JimboJim]

I dont know how many solenoids I have replaced and never did solve the problem. Fords require a full 12.4 + volts at the starter read this
http://www.greenflagauto.com/forum/search....te=voltage+drop

Do a voltage drop test across the battery terminals and the battery cables from the battery to solenoid and solenoid to starter repeat on negative side. I assume you have cleaned the battery cables but because of the voltage requirements they must be almost pristine clean so recheck them check the cables for bad spots insulation bubbling or any other sighs of corrision. If all of this checks OK then replace the ignition switch. Not the key but the electrical part, I suspect this is your problem but I would check the other items first as there is a chance they are your problem and all it will take is time to check them. The switch is quite easy to replace.

10/21/09 Hello Again: I thought I'd post a follow up reporting my latest observations. I learned today that - when the car refuses to engage the starter - if I attach a VOM to the trigger post on the starter solenoid & twist the key to START, there is no voltage going to the activation terminal on the solenoid. Sounds like the ignition switch, correct?

[Crew Chief]

Yes But check at the solenoid first there should be battery voltage at the small wire if not replace the switch if there is keep checking as I mentined in first reply. These are usually the switch bad cables or terminals.

[JimboJim]

Yes But check at the solenoid first there should be battery voltage at the small wire if not replace the switch if there is keep checking as I mentined in first reply. These are usually the switch bad cables or terminals.

11/4/09

Hello: Just in case anyone is interested - the problem with the car was a faulty transmission position safety switch. I noticed that the back-up lights on the car were mysteriously not working. This can be an indicator of a faulty trnasmission safety switch. I replaced the switch & the car is its old-self again :-)