Oh good glad to help on that part. I knew it was pretty specific behavior. I would say that the reverse cooling on these is prone to easy damage, because mine began to have a problem earlier this year in april. We had a freak sleet/snow storm that caught me coming home. I got stuck in the driveway inclined downhill. I revved the engine a bit on an inclined slope nose forward, and I believe the overflow poured out causing a hot condition that cycled out of control damaging the newer thermostat that had been fine for a year at that point. Took awhile to figure out because sometimes it would stick a little and then be fine, until the weather got hotter.

 

You asked why change a good setup?

I know personally when I had the problem, the main temp sensor was reading pretty cool, thus not triggering fans. It seemed as though the fans were not working. But no. The top end is overheating in local pockets and the fans are ignoring the gauge reading because it is separate. Potentially a bad condition, and not a good setup really if you think about it.
I knew it was odd though because the engine did not exude heat like a normal car overheating. My fans operate normally, but they do ignore the hot pockets of this condition. Perhaps you could upgrade this. I know they have a dual setup sensor, but you could also rework it manually.

 

I see. Perhaps you could use the sensor in the head for the PCM and use the sensor in the pump for the gauge. I'm not sure how it could be done though as they have different connections but inside they're just thermistors.

Anyway, I think the explanation for the drivers side fan being dead is that I didn't hook it up correctly when I did the water pump. But, I still want to get the fans wired the way they should be.

From the wiring diagram (which I'm not good at reading btw), it seems like the fans get their power from the dark blue wire coming out of the PCM? I know the wire I currently see the fans getting power from is a darker color and a larger gauge but what if the PO spliced it in?

I'll be getting into the wires tomorrow morning so I hope I can easily get to the bottom of this mess.

 

If properly filled and maintained, the reverse flow cooling system works fine - it's what allows the engine to run the high compression ratio, and make superior HP and fuel economy compared to other engines of the era. I've had my Formula since I bought it new in 1994. It's had the same Hypertech 160° t'stat for 18 years. Even supporting a 7,000+ RPM stroker, making 800 HP and doing 5,000+ RPM burnouts, the system has never overheated, never lost coolant, and never caused a problem of any kind.

Never ceases to amaze me the way people trash the LT1.

 

The PCM supplies no power to the fans. It supplies grounds to operate the relays that supply power to the fans.

 

I see. So it came off a relay? I guess I know where to dig in tomorrow lol

 

Well mine was filled properly though. It was the incline and short duration of revs that did it in. I realize the high compression thing, hello people like us are not dumb. The design can be sensitive though and crucial. Some people note the lines in the back getting clogged often. In this case the thermostat can get clogged/stick, which apparently you knew nothing about. lol

 

What "lines in the back" are you claiming "get(ting) clogged often".... 15 years on this site, and that's a new one to me.

Color me ignorant.

 

Clogging in the cooling system is a result of poorly/no preventative maintenance, and is in no way an LT1 characteristic. Mixing Dex-Cool with non-Dex-Cool coolants for any substantial period without flushing the system, will cause sludge to form.

My 95 with 220k+ miles (all original, except for water pump & opti), and the cooling is perfectly sludge and rust free.