Hunting the source of the problem with SN95

jacobn4056. · Jan 16, 2024

Hey folks. I have a gremlin to hunt.
I’m not sure if it’s electrical but it’s a check engine light. I have a 1995 Ford Mustang GT convertible 100k miles all original stock equipment.
For the longest time I’ve had a serious problem. While running whether driving or not, and at times intermittently, also almost exclusively at operating temp I have a check engine light pop up and the car looses all power. Idling the car flutters and bumps just barely enough power to run when this happens. I pulled the ccrm and cut it open. I found the board to be burned around the farther right relay if the plug in is facing away from you. From what I’ve saw it is the Low Fan relay. When it blew it stayed in that condition. I replaced the ccrm and have had the same issue on and off. With the new ccrm -When it happens it usually continues until the car sits for a few hours.

It’s not drivable of course. I’ve had input on the problem ranging from the ECT sensor to the distributor. Replacing the distributor was one of the first things I did. As it wasn’t worn at all but was very aged. I got a distributor that looked as if the ignition module mounts to the distributor. Of course mine is under the air box.
I had someone tell me that there is no crank position sensor in that distributer and that the stock distributor did.
Seemed to be running the car fine when not in its check engine related condition.

I finally got the distributor I wanted in stock and on the way anyway.

My question is what is the problem here.
It seems all things point to a short In the fan harness wiring.
Anybody else have similar experience?
Share your thoughts and experiences

jacobn4056. · Jan 16, 2024

Update

The engine isn’t running hot.

jacobn4056. · Jan 16, 2024

One more update folks. It didn’t have a problem the first several monthes I owned it. And it runs fine for a little while now with new wve ccrm. Sometimes longer than others. But I can’t drive it. I know for a fact it will foul its plugs beyond running at all as I’ve been trying to fix it.

I haven’t scanned since new ccrm so I don’t have a code. I went to all parts stores and a buddy’s shop who claimed to read old OBD. No codes on digitals. When I got mine in made for the ford year supposedly. it was just a beeping box. I think I got a good translation to the first code listed. Iac valve. A new one didn’t stop the problem. Way back then.
I also heard that if you rub the right wires together the check engine light will begin to communicate with you via Morris Code.
This has been one of my favorite cars my whole life. This one in Particular. I wouldn’t say I’m not mechanically inclined. I grew up in a parts store. Every day. But I’m stumped at this

cobrajeff96 · Jan 17, 2024

Check grounds. Make sure the engine ground in particular is clean/tight and has a path back to the negative battery terminal.

If this happens while car is running at driving speed, it's unlikely a cooling issue as the air stream alone is enough to keep it cool (greater than 45 mph for a few minutes). That is unless the T-stat is stuck closed or some other big problem.

So more than likely it's either fuel/air/spark.

I know very little about the pushrod era, but here's a 96 CCRM document or two to ponder over.

You can also try getting in touch with Mark Olson at accutach.com

He's a solid dude when it comes to anything SN95 Mustang electronics.

96blak54 · Jan 17, 2024

I chased a similar issue when i had a 2door 92 ford tempo with a 2.3l. I did the normal parts swap, spark plugs, plug wires, distributor cap, trouble shooted bad wiring and such, but never sourced the issue. The one thing i didnt chage was the pip pickup within the distributor. After a locked up rear wheel brake and trouble sourcing replacement parts, i decided to just scrap the car because at the time i didnt have any time to keep messing with it and just bought a newer reliable daily driver. A few months later speaking with some ford guys and explaining what the car would do and run like i am convinced the distributor pip was faulty. The car ran super great, super strong untill at times it would begin to stumble jerk run like crap. Barely enough crap power to pull itself, idle extremely rough. And just like the problem would come on, it would leave like nothing was wrong and very difficult to track down. Im not saying your car pip is bad but after speaking to a few great ford guys i know, im convinced the pip was faulty in mine. I just wished the info was more available at that time, because i liked that car. Wished i kept it.

There are plenty of youtube vids on replacing it and possibly diagnosis of a bad pip, but if you haven't changed yours in the mad parts swapping we are all accustomed to, you might want to try swapping it.

jacobn4056. · Jan 17, 2024

Thanks y’all.
no it happens regardless of speed.
And fan stays on even when the engine is off, when this happens. Engine runs fine until this happens and check engine comes on.
I have a distributor that I like on the way.

But it has a new distributor in it
I’m not convinced it’s the right one because it has a mounting plate for the ignition control module. It was found for my car. Mine is on the wheel well under the intake.

tvsn95 · Jan 23, 2024

My suggestion is to remove the ECM and open the cover, look at the capacitors very closely. Good chance they are bad. they are cheap and fairly easy to change.
the pip IS the crank position sensor on our stuff. and yeah you have the TFI mounted on the fender as opposed to the side of the dist. PiP's normally just quit, But ,,,, TFI's can be funny but normally just quit.
I suspect that the relay in the CCRM failed due to a tight fan motor bearing,( drawing too much) usually burns up the motor connection also. common problems.

jacobn4056. · Jan 23, 2024

I have a fan. I think I’ll return it for the motor though. Capacitor are leaked out and I have it boxed up ready to go I don’t have an ideal workspace for that.
I think I found the problem or one of them. My water pump had a leak out of sight and just enough to saturate those cables that run around the bottom of engine and oil pan. Both were soaked.
I don’t think anything is too bad to clean up. I knew I lost some water but hadn’t saw those harnesses and their location.
I pulled water pump and have a fan on them. Will dry them all night and clean things up.

jacobn4056. · Jan 23, 2024

jacobn4056. · Jan 23, 2024

So I thought about amps but don’t have a meter for those kind of amps. Does anyone know of something I’m missing to test the draw of the old rad fan?

tvsn95 · Jan 23, 2024

jacobn4056. said:
So I thought about amps but don’t have a meter for those kind of amps. Does anyone know of something I’m missing to test the draw of the old rad fan?

Hey buddy
If the connections are obviously burnt just replace,, they are easy and cheap.
seriously the caps are easily found on ebay.
you must remember they only built that ECM 2 years,,,that all
the conversion are not EXTREME but NO fun . the pin diagrams and the changes in lingo make it tougher,,,,,then you are still stuck with a 30yr old tech.
Fixing what works is pretty simple. I use a soldering iron and a pin drill from a welding supply house , used to clean cutting tips.
make sure you put the - on the Cap in the same place.
good luck,,,,this shit ain't that hard

tvsn95 · Jan 23, 2024

tvsn95 said:
Hey buddy
If the connections are obviously burnt just replace,, they are easy and cheap.
seriously the caps are easily found on ebay.
you must remember they only built that ECM 2 years,,,that all
the conversion are not EXTREME but NO fun . the pin diagrams and the changes in lingo make it tougher,,,,,then you are still stuck with a 30yr old tech.
Fixing what works is pretty simple. I use a soldering iron and a pin drill from a welding supply house , used to clean cutting tips.
make sure you put the - on the Cap in the same place.
good luck,,,,this shit ain't that hard

OHH on the fan motor,,,these things slow down and you will swear it's ok,,,spin it with your fingers and if it does not free wheel , its bad

tvsn95 · Jan 23, 2024

tvsn95 said:
OHH on the fan motor,,,these things slow down and you will swear it's ok,,,spin it with your fingers and if it does not free wheel , its bad

The V6 motor is the same

tvsn95 · Jan 23, 2024

tvsn95 said:
The V6 motor is the same

Also , the SBF will leak coolant around the water pump bolts, these MUST be sealed at the threads, anaerobic sealant is best

jacobn4056. · Jan 23, 2024

I’d enjoy repairing it myself but I’m just not equipped. I could get the few things I would need cheaply but it’s just not worth a mistake to me. Plus I think some of the traces are messed around the capacitor.
I can get use bluestreak reman or ship it off. Bluestreak claims to be better and looks different for sure. I’ll have mine repaired regardless so it isn’t lost to everyone. Repair is about $150 and 5 days in house.