North American Turbocoupe Organization

Thanks everyone for all the fantastic advice. Here I am again. Seems like when I get something fixed. Something else goes. Gotta love it. Love my Turbo. Here is my quandary. NOW-after driving the car around town for 15 or 20 minutes and parking it to idle down and cool the engine. After about 20 minutes of sitting parked and running, the car will idle down to about 500 then jump back up to around 1200. THEN just stall out. It will not crank. When you turn the key, the engine won't turn over-it'll just click away. This has happened 2x. The 1st time the car restarted the next day. I didn't try jumping it off. The second time I attempted a battery cable jump off as soon as it stalled out. It fired up and continued to run until I turned it off 5 or so minutes later. I have no issues while driving the car. No warning lights come on-check engine, turbo, etc.... The battery needle shows nearly a full charge(1year old Motorcraft heavy duty battery). The car is in the shop. They have checked the alternator and battery. Neither have issue. Anyone have any ideas? I have no way of pulling the codes. Here is what I have had professionally replaced in the last 6 months:
Timing Belt
Water Pump
Thermostat
Idle Air Control Valve
Oil Pressure Sending Unit
Main Fuse
K&N Air Filter Element
Oil w/K&N Filter
K&N Fuel Filter
PCV Valve
Plugs
Wires

UPDATE: soooo the mechanic (30 years experience) replaced the alternator. Car ran fine for 30 miles. Then-Same thing-A stall out. I was able to jump the car off and get it back to the shop to have them "look their calf over" again. Now the word is that the alternator is unable to carry all the accessories-headlights, fog lamps, cooling fans, a/c , etc while sitting idling so it kills the battery by drawing it down from "borrowing power" to compensate. The mechanic told me this was a common problem during those days. I owned an 80 Mustang back in the day and never had this happen. I've never heard such. I've owned this car for a year now with no issues until about a month ago. This tells me this is something other that what is being guesstimated. Anyone have any thoughts?

Did they check all of the electrical connections between the battery, starter solenoid, and starter; and check for corrosion in the wires? This is a very odd problem.

^^^^^^ +1

In addition to what Brian said, have all major grounds been checked, especially batt neg to engine and engine ground strap. If it were mine, I would replace both batt cables and the engine ground strap with new. Cheap and easy to do. I have seen batt cables that look good externally but are seriously corroded under the insulation.

Also in your list of parts replaced, you state "main fuse". There is no such thing in a TC. Main fuses (i.e., megafuses) didnt enter the automotive world until the late 90's. TC's use fuse links for all high current circuits.

Ah. Thanks for the info. I thought main fuse was a bit odd on a 28 year old car. That is why I'm not a mechanic. Lol. When they listed it on the repair order, it was listed as "Main Fuse". My mechanic is going over it with a fine tooth comb. I'm sure they'll find it and find themselves a bunch of money for finding and fixing the ailment. Thank you.

Hi Lorain088,

I see you are in Savannah, GA. It gets a bit hot there in the summer, does it not?

I live in Phoenix, AZ. We know a little bit about heat--a week and a half ago it was 121 degrees here. Of course, "it's a dry heat", not like yours. During that heat wave the humidity went from 7% to around 20%.

I saw you listed that you were running a Motorcraft Heavy Duty battery. My experience is, that ain't gonna cut it. These TCs are VERY heavy on amps/volts. The first few years I had my 88 TC I was going through a battery a year. These were Exide top of the line from what was then Checker Auto Parts (now O'Reilly's here). In addition, I was also burning out an alternator every other year, as it tried to keep up. (Driving with A/C on all the time--a must here, as it probably is for you), lights, etc. was too much for the system.

SOLUTION: simple enough. Sears DIE HARD battery. I now average a battery every 3 years, and an alternator every 7 or so. Big difference, right?

DISCLAIMER: This might not be a solution to your current problem. BUT I think you'll be much happier with the upgrade, overall. I know I've never looked back.

Thank you for your advice. I'm gonna have to make do on the MC battery. That jewel was $150. I'll look into a Die Hard next go around. Yes it is HOT here!

Or upgrade to a 130 Amp G3 alternator. No matter what battery you have, an undersized alternator will seriously shorten the life of the battery.

I have had batteries last 7+ years in my TC, and I replaced them not because of failure, but because of age and fear of getting stranded on 2000+ mile road trips.

Thank you Jeff K. The shop swapped out the alternator they put on initially for an upgraded alternator. Also, I had both terminal cables swapped out too . Man-I should have done that to start. Those old ones looked like somebody had beat them and spread them with a claw hammer. A downside, the tech broke off one side of the starter solenoid when he was disconnecting the cables. (Of course) It was the FOMOCO original. I guess it didn't hurt a necessary replacement. All is good for time being. If you start driving something that has sat mostly for the last 20 years, these things are bound to happen. Thanks for the heads up and sound advice.