CCRM, beating a dead horse

[94' Five.0]

I've spent the last few hours reading through old posts about fan issues, but I haven't come across my exact situation yet. I installed the manual fan switch a while back via the instructions in the FAQ and it always worked fine.

My AC hadn't been working very well for a couple months so I usually ran with it off along with leaving the fan switch off. My compressor finally seized not too long ago and I decided to overhaul the AC system. After fixing the AC, my fan woes began.

After reading through old posts and doing my own troubleshooting, this is the issue I'm faced with. The fan will turn on at low speed automatically when warmed up. This leads me to believe the ECT is working properly. High speed however, does not work. Neither with the AC on or with my old fan switch. I've run 12v to both the low and high pins on the fan and they seem to work fine, so I don't think there is a problem with the motor. I'm starting to think the high speed relay inside the CCRM is the culprit.

Should I try swapping out the CCRM or just bypass it and wire up a couple relays with two switches? Would standard 30a bosch relays be enough to run this? If I connected a switch for the high speed would it damage the fan if the low speed was still being controlled by the CCRM?

 

[HISSIN50]

You and I had similar issues.

Engaging high and low speed simultaneously does shorten the life of the motor - it also makes the thing run at a little more RPM than low speed. Not good.

You could wire up two stand-alone relays to control just high speed (since your low works). the first relay would engage high speed and the second would be for shutting low speed off when high is engaged. If your motor never reaches ~208*F while your AC is on, you would likely be able to bypass the second relay since the risk of running both speeds wouldn't be an issue.

Another option: Redo (or use jumpers) the fan connection so that the low speed terminal in the wiring harness goes to the high speed fan terminal.
I considered this but did not because of the high speed fan terminal issues that these fans have. I went with a DcControl.com controller instead.

For relays: A 30 amp would likely suffice for low speed. For high speed, I'd want more. You can get a Bosch 75 amp relay for 30 bucks. Or FFI sells Bosch 50 amp relays for like 6 bucks (great deal). I bet you could use two of those for the speeds (especially if you step the speeds. E.g. when I wanted to use high speed manually, I let low run for 20 seconds first so the jump to high wouldnt take as much start-up power).

I'd consider one thing: add up what you might spend doing all this (esp if you decide to use a controller from the parts store - I think toggles are a pain, esp if this is your driver). Then compare prices to the unit I listed. I did this with a friend - he was going to spend 92 bucks on relays, controller, wiring stuff, etc. The Variable controller was a much better deal (I have no affiliation with Baskin or his controllers - I just think it's an awesome unit).

Random thoughts.

Good luck.

 

[94' Five.0]

Thanks for the reply Hissin. Lots of good ideas there. I'm not crazy about running the fan completely on toggles as its a daily driver, but as it stands now the car just can't make it on low speed alone in the heat down here.

I am having some trouble finding high current bosch relays though, does FFI have a site?

Maybe the quick swap you mentioned about flipping the low and high speed pins would be a good way to get by until I figure out a more permanent setup.

 

[HISSIN50]

I was basically in the same boat with low speed not cutting it in higher ambient temps. I traced my issue to the PCM not switching from low to high when the A/C was on, and decided to just go with the DC Control unit. I love it.

Sorry, FFI is my shorthand. Here's the page with the $6 50 amp relays (along with the 75's if you desire that):

http://fordfuelinjection.com/?p=68


Good luck bud. And let us know how what you choose works out for you.

 

[urban96]

im having a similar problem.

my low speed turns on just fine normally but no high speed.

if i turn the a/c on though the high speed fan will turn on

i replaced the CCRM (got a used one for cheap) but im still having the same problem

 

[HISSIN50]

im having a similar problem.

my low speed turns on just fine normally but no high speed.

if i turn the a/c on though the high speed fan will turn on

i replaced the CCRM (got a used one for cheap) but im still having the same problem

Have you let the car get up to ~228*F to verify that high speed doesnt come on by itself? Most of us wont let the car get that hot................

Good luck bud.

 

[urban96]

Have you let the car get up to ~228*F to verify that high speed doesnt come on by itself? Most of us wont let the car get that hot................

Good luck bud.

yes, but not for long... i uaually always have a/c on since its been hot out lately. i turned it off to give it a break and temp stayed fine for a while (while i was moving) hit a lil traffic and to my suprise temp climbed up to like 220

i thought maybe its just doin that because its hot outside, so i let it go for a min keeping an eye on it. it went to just past 230 and then i clicked the a/c back on and temps went back down to 210

coolant is pretty new, new universal summit alum radiator, new FMS high flow WP

temps were from autometer gauge put inplace of where the stock temp sender goes (stock sensor was moved to the water neck just so the dash dosent look dead)

 

[urban96]

tomorrow im going to do some testing

pin 14 gets +12V for low speed

pin 17 gets - for high speed (14 dead)