Are there any differences between the types of CCRM that would affect the proper operation of the engine and it's support systems? I had a F48F-12B577-AA and I have a F48F-12B577-AB to replace it with. I can't find any info on the net about the specific differences between part numbers.

 

From my research,a part with an earlier revision letter (xxxx-xxxx-AA) can normally be replaced with a part that has a later revision letter (xxxx-xxxx-AB) & everything will run ok,but if you do the opposite
from (xxxx-xxxx-AB) to (xxxx-xxxx-AA),it likely wont work.
Im pretty sure theres a difference between a 3.8 & 5.0 ccrm,but if your suspect ccrm & your new ccrm are both for a 5.0 and their revision letters are following the structure above,they should be compatible.

 

Without specific knowledge, hard to say. CCRM contains individual relays to power up fuel pump, fan, and others I've forgotten. On my '94 5.0, I got rid of the damned thing altogether. Why replace a bunch of expensive components if only one fails? Higher parts cost?

 

Im purely speculating & assuming here & Im not by any means telling you what to do,but I would wager a bet that if you were to do a short writeup (with clear instructions & images) of how you went about ridding the CCRM,alot of 94-95 owners would likely be very interested and appreciative for this.It seems like it would be even more helpful,especially in terms of expense,to an owner that only has one portion of the CCRM thats bad vs the entire unit. IOW- if only the fuel pump relay portion was bad,the owner could simply replace just the fp relay vs having to replace the entire thing,which is quite pricey.I guess putting all the relays in one spot seemed like a good idea during the design phase of the 94-95 models, [ plus Ford knew how much cash they would make considering how impossible it would be for a 94-95 5.0 to run without a CCRM. IOW- a 94-95 5.0 owner would have no choice but to buy the CCRM,since it contains so many imperative components (relays) ] but since you've got a work around for this,it would probably be very helpful.

 

Glad you asked! Here's the car the day I bought it in May, 2014. 94 GT 5.0HO, manual. My underhood inspection at seller's house was not it's usual intense best. Reluctant wife and all....Things different having owned 3 Foxes, 89, 90, 93 Cobra, were the engine bay layout, group 65 battery no fit, electric fan (which I was blissfully unaware of still) with clutter between radiator and front of engine, THAT's where the CCRM, ridiculously high coolant catch bottle, ABS Module were located!



The fan could have been intended for a Mack Truck! It was HOT weather, in the Desert, maybe 115`, My test drive was limited, but bought the car, drove about an hour or so, noted the temp. gauge fluctuated between two extremes: low end of gauge and high, taking about 10 minutes for each cycle. Typical of electric fans which must by nature be designed to not cycle too often, as the components just aren't able (relay contacts) to hack such service conditions. Now, my 94 Explorer with clutch fan maintains gauge temp. steady as a rock, even idling with max AC in summer heat. A well-designed system. Most engineering thought dislikes thermal cycling, ad electric fan given. Fan first thing needed to go! I bought a good thermal fan clutch, maybe as specified for Explorer, and a blade having acceptable clearance sizing (comes within about an inch of the underhood, close). And began moving a bunch of ****!



No sweat the small stuff. SN95 turned out to have 3/4-inch pump hub instead of ages-old 5/8, so made up appropriate spacer/adapter, visible below. ABS Module and it's harness were easily re-routed to RF fender well, below the TFI (factory-location?) mounting. Same for CCRM, until I ripped it apart and individual-mounted and wired it's do-dads, also RH side. Now, there's a nice open space between radiator and pump, occupied only by a good-working fan. Now the electric fan lovers will hate me...argue with me, etc.......But this thing far excels over what Ford delivered! The AC blows colder than any I've ever had; after a few minutes, it's always down on "2" or "1" on the blower.

Here's the thinking: electric fans MUST operate between two limits (or more, if multi-speed). Turn ON at maybe 200 degrees (thermostat must be open), run until temp. drops to maybe 160, then turn back on, cycling thus up and down. A good fan clutch varies the cooling effort infinitely, no steps, thus maintaining coolant temp maybe +/- 10 degrees. The clutch free-wheels when not moving air through the radiator. Pitch flex-fans, fixed-blade, energy-hogs.No energy waste. Clutch thermal parameters are designed about thermostat-maintained coolant temp. Even seems plenty efficient without a shroud, stay clear!