Attempts stall, Idle Pulses 600-800 rpms, horrible MPG

[Selectron]

Originally Posted by searcherrr

Resistance is futile.

Chuckle, chuckle. I must admit, if I was trying to fix your Windstar I'd have lost my sense of humour long ago.

The resistance value you measured will be ok. Notice the '5%' marking - that's the component tolerance of +/- 5%, so although its nominal value is 62 ohms, its actual value can be from 58.9 to 65.1 ohms. You would need to remove one leg from circuit and measure again to be certain, but chances are that's a healthy resistor and you can forget about it now. Oh yes, and the 5W will be indicating that it's a 5 watt device.

[Selectron]

There was a suggestion from Wiswind back on page one, to unplug the fans very temporarily and see if the stumble still happens. I reckon that would be well worth trying.

First, I'd do the test which I suggested on the previous page to eliminate the ECT sensor - switch the A/C on while the engine is still cold, and if it still stumbles when the A/C is switched off then that eliminates the ECT sensor and associated circuit.

Then for the second test, I'd unplug both fans. Pull the plugs directly at the fans but leave everything else intact. The PCM will then still get its feedback signal via fuse W into the PCM, pin 4, so it will think the fans have been successfully activated. Allow the A/C to run briefly and then switch it off. If it still stumbles then the fans will also have been eliminated (don't forget to plug 'em back in!).

Actually, you can do that in a single test - unplug the fans and then, with the engine running but still cold, run the A/C briefly. If it still stumbles at switch-off then you know that neither the ECT sensor nor the fans are responsible. That's a quick and easy test which would narrow things down considerably.

[searcherrr]

Affirmative Captain.

Thanks for the explanation of the markings on the resistor. I was hoping you'd say 64 would be ok. I realized to get a better reading I'd have to disconnect it, but I really don't want to disturb the board more than I already have.

Today's Agenda (lol):

Prior to tests
1. Clean CCRM with electronic parts cleaner and allow to dry completely
2. Reinstall CCRM etc... with temporary seal (DUCK TAPE).
3. To keep engine cold will turn off engine between tests

Test Hit List:
1.a. As had planned (just was waiting for exhaust to be finished): Radiator fans unplugged test (a/c not active) - while cold
1.b. Passenger side fan unplugged; driver fan plugged - while cold
1.c. Driver fan unplugged; Passenger side fan plugged - while cold
2. A/C Turn off test while engine cold (fans of course plugged back in)
3. Test PCM ground wire and cont to CCRM

After Tests
1. Remove CCRM
2. If haven't isolated issue test fans diodes in CCRM - Not sure I'll be able to accomplish this because I cannot trace the path of the fan pins from the connector unless I remove several pieces on the board.
3. Reassemble CCRM and seal it better (unless I need to leave it some air?; debating on putting some filter material at its air openings vs just rtving it shut)
4. Reinstall CCRM etc..
5. May turn efforts to looking at the fuel system if electrical issues aren't found in this series of tests

[searcherrr]

Testing for today was cancelled due to inclement weather. lol .. and cause I woke ma azz up so late.

And so left with not knowing what to do with myself I decided to take a much closer look at the CCRM and clean it up REALLY good.

First of all I think I goofed using the electronic parts cleaner (lets just call it e.p.c.) on the circuit board and associated parts as some sort of invisible plastic film apparently lifted up off of "some" of the board components and some of the board itself. Should I be worried about this? Was this weather protective film?

Secondly - got the board nice and clean and unfortunately felt I had to remove the flaking plastic.

Thirdly and probably most importantly - I spent a great deal of time on the connectors and inspected each one correlating it to the CCRM diagram.

-All pins were corroded to some extent
-Pins 6 & 7 were HEAVILY corroded with some metal decay/erosion and the tips of the pins after cleaning reveal maybe 25-35% loss of metal material just at the ends. These pins are also a different color than the rest now. They are slightly reddish/silvery almost sorta bronze looking, but not quite. Oxidation?
-Pin 18 was pretty heavily corroded as well with no erosion
-Pins 1, 2, 4, & 11 were moderately corroded with no erosion

6 & 7 pins (whaddaya know) from the diagram are for "Reduced BATT (Cooling Fan Control Relay)'s" function.... which is what sports fans? yes.... its what I'm having problems with. I was able to scrape enough off to make them shine again (not just the tips, but where the connector harness slides in and makes contact). Since these particular ones for "low speed fan operation" are so worn out I wonder if the cooling fan dropping resistor behind the headlight being broken eventually causes and then exacerbates the failure of the CCRM?

18 is the fuel pump - more irony? Perhaps not.

1, 2, & 4 were moderately corroded and again apply to the cooling fans

13 - 24 are hardly unimportant, but were just moderately corroded as well

I scraped with wire brushes and picks at every pin to get it all clean and then washed it over in the end with the e.p.c.

Lastly, I would really like to know if me sealing all the openings on the CCRM will be bad (heat dissipation) and if it really needs these air openings as I don't quite understand why (though its covered) its basically left open to the elements.

[Selectron]

I've never been a big fan of that parts cleaner stuff, well not for cleaning PCBs anyway. My tried-and-trusted method for PCBs is just to sweep the debris and dust off with a soft-bristled paintbrush - just a regular 1" brush such as you might use for painting a window frame. Provided there hasn't been any spillage on the board (coke, coffee, etc.) then a brush does the job just fine because it can sweep underneath the components and reach into all the little crevices.

The transparent film will be a 'conformal coating' - it's an insulating layer applied during manufacture to provide protection from atmospheric moisture and to inhibit corrosion. The unit will work just fine without it so it's not a cause for concern. If the CCRM ends up going back into service though then in the interests of future reliability it would be a good idea to give it another coating fairly soon - you can buy it in an aerosol can at any good electronic components store - just ask for a can of conformal coating spray. That stuff isn't applied to all PCBs by the way, so it won't be on your TV or DVD player - it's only on the CCRM because it's intended for outdoor use.

It sounds like you've lost some of the plating on the connectors, revealing the base metal underneath. Provided you have clean metal at the contacts it will work ok for now, but reliability would be compromised over the long-term. The base metal probably has a higher contact resistance than the plating, and it won't be as corrosion-resistant. If it's going back into service then I'd be applying something to inhibit corrosion. WD40 might work, but I'd probably use petroleum jelly, or dielectric grease. If the plating has been eaten away by corrosion though, then the base metal might never give a good, reliable contact and it might need to be replaced.

As for sealing the unit, I'd be guided by the way it was originally constructed and restore it to its original state, so if it was open then I'd leave it open. The relay coils will all dissipate some heat, as will the ceramic resistor, and at the opposite side of the board there's a semiconductor bolted onto an aluminium heatsink, so that clearly dissipates significant heat too. If the manufacturers wanted to seal it they could easily have done so, so I assume they left it open to allow some ventilation, and that's the way I'd leave it.

Regarding the corrosion on the connectors - I could see how that would lead to the fans running slow, or failing to run at all, but I can't think of any way it would cause the stumbling at fan switch-off. I'd be very happy to be proven wrong though, so I'll hope that when it's plugged back in, at least some of your symptoms will have cleared.

[searcherrr]

Thank you for the info on the "conformal coating spray" as I know I will not feel right about putting it back in there without it. I would've never guessed you could buy this stuff.

Dielectric grease is a good idea. Aren't there two types of this and you have to make the right call on which to use? I already planned on RTV sealing the connector to CCRM though too.

Gotcha. Leave it open as the manufacturer made it. Makes sense to me. This is what I was leaning towards, but I just didn't like all the debris in there.

When I was cleaning the connectors/plating I made sure afterwards that all pins and especially pins 6&7 still came together pretty tight rather.

I thought about replacing those pins too, but I have no way of knowing where I'd get new pins of that same type other than from a junked Windstar.

Its really horrible weather today so looks like another stalling of getting this done. I'm glad I taped off the harness and other things when I took the CCRM out.

[wiswind]

I agree with the issue of removing the plating on the connectors....although....once they are corroded to the extent you mention....the plating is done for already.

I also agree with the "conformal" coating spray....don't overdo it.....and do NOT get any on any connector pins.

I would stay AWAY from RTV around the connectors.......and as a note....any time you use RTV around electrical / electronic "stuff", make SURE that is is labeled as "Electronic Grade"....
If it is NOT electronic grade, it will cause corrosion.

In all honesty....I would consider a new CCRM as the new replacement has better sealed relays......as FORD upgraded them from the original specification.

[Selectron]

The two types of dielectric grease would presumably be non-conducting, and conducting. To be honest it's something I never buy - I just keep a tub of petroleum jelly in the toolbox. That's non-conducting by the way, and if you get dielectric grease then be sure to get the non-conducting type.

Unfortunately, replacing the pins on the CCRM connector just isn't a practical proposition, so if they've deteriorated to a point where they're no longer going to be reliable, then replacing the CCRM is the only realistic option.

[searcherrr]

Thanks guys.

Ugh.... new CCRM contimplating.

I wasn't gonna RTV anywhere near the pins. I was just gonna plug the harness/connector together, screw the bolt in, and RTV seal the outer edges where the harness/connector meet and possibly where the wires go into the plug too.

If I spray the coating I'll tape over the connector first.

Dielectric grease vs petroleum jelly - Wouldn't the jelly melt and/or liquify under engine bay heat? LOL - I've noticed in the past that just body heat causes it to get slippery.

I think I'm going to put the old CCRM back in and see if any problems have been resolved. If it is resolved what I may do is perform the mentioned tests and add a test by putting that 15A fuse back in the wrong way as it was before and see if the problem returns. If not then I'll know for sure .... CCRM.

[searcherrr]

Another day of 93% humidity and thunderstorms. Nothing new.

[searcherrr]

Today was a big turnaround for the weather. Awesome clear day and low humidity.

The old CCRM is back in and I did not buy the conformal coating as it would be worthless if my cleaning efforts did absolutely nothing which is exactly what it seems.

I don't know why I was gonna do cold testing besides the A/C switch off thing.

1. No matter what I do for tests the engine does not try to stall when the van is cold to moderately warm, though in these conditions it does a "quick" hesitate (very quick) when the fans go off... not nearly as bad as when its fully hot... but its definitely sorta like a hiccup and this is only when COLD and after switching off the A/C..... which really just equates to again when the fans turn off. Overall I'd say fan operation works as normal when turning the A/C on and off.
   
   
2. When the A/C is switched on the fans kick on every time. I mention this because when the fans come on does not seem consistent without the A/C on using the temperature gauge as a guide for "when" it should kick on.
3. I unplugged the fans when the engine was fully hot and let it get up to the mid-range R before plugging them in again. 1st did so with A/C off and then A/C on and then off. There was no "attempt" stall during the fans being unplugged in either of thes tests.
   
   
4. Basically when HOT when the fans turn OFF from turning off the A/C or just on their own without the A/C the van still tries to stall. I had just done it while it was cold and it had that hiccup. Does this mean I've ruled out the fans and the ECT? or do I need to do this test warm?
   
   
5. Something I did notice was how low the RPMs go when I turn the wheel. This of course would be the power steering pump pressure switch (I think). I believe the a couple times it went a lil under 500 RPMs, but after that would hit bottom at 500 consistently. Probably doesn't mean much.

On a darker note I bolted up the exhaust today and I'm very unhappy to relay that the flex pipe does not line up right with the rest of the exhaust and the ypipe or the other way around. The receiving muffler side is slightly pointed down and I have no idea why. The magnaflow pipe will not allow the flanges to meet flush as the pipe extends "slanted" beyond the flange welded on it. I have to say I've heard lots of great things about Magnaflow, but this experience has me never wanting to buy from them again. At least the weld adjustment to the pipe finally got the O2 in the right position so that it does not hit the steering rack. I will be bringing the van to the same weld shop tomorrow to finish the damn exhaust once and for all. I'm worried the flex-pipe is bent beyond its tolerance cause I can see light through the tiny holes on the other side. I'm so f'ing aggravated right now. I need this crap to be over.

[searcherrr]

New CCRM on order from Bob Utter Ford in TX. $94 before tax/ship.

Exhaust - Van at shop to have this resolved. I certainly hope it does not sound NEAR as loud once done properly as it did driving it over there because it almost makes me feel like putting the old Ypipe right back on it. We'll see.

[Selectron]

I reckon those tests have eliminated the fans, for two reasons. First is that if the fans had been sending a spike back into the PCM, sufficient to cause it some momentary confusion, then the symptom of near-stalling would happen regardless of engine temperature, and that is not what you are observing. Second - and more conclusively - there is no stumbling whatsoever when you unplug the fans manually. Therefore there is no spike, and so you can consider the fans to have been eliminated.

I'd say a slight question mark still hangs over the ECT sensor, especially if you think it isn't always switching on the fans at the same temperature. At first glance, the fact that the engine stumbles when switching off the A/C, with a cold engine, would seem to rule out the ECT, but before you could be certain I think you'd need to measure its resistance when hot.

As Tripletdaddy pointed out a while ago, in addition to using the ECT sensor to determine when the fans should be switched on and off, the PCM will also make use of it when setting the fuel and air trim, etc. It's possible that although its resistance varies sufficiently to activate the fans, it might be sending an inaccurate indication of the real engine temperature to the PCM. I don't see how that would cause the stumble at switch-off, but to err on the side of caution I'd measure its hot resistance anyway. You already gave the resistance as 25.35 (I assume that's kilohms) at 86ºF, which is just about exactly where it should be according to my chart. If you have a means of measuring the engine temperature then I'd measure the resistance again at a higher temperature to check if the resistance drops to the expected figure, and if so then I'd say that would conclusively eliminate the ECT. If you don't have a temperature probe and you don't want to detach the ECT to test it in boiling water, then you could wait for the thermostat to open and then switch the engine off and check the resistance, using the thermostat rating as a reference point on the chart.

If there's a new CCRM on order then there probably isn't much else to do in the meantime eh, except keep your fingers crossed that it clears up at least some of the symptoms, and hopefully all.

[12Ounce]

Have you tried disconnecting the ac clutch coil? Its a large coil ... would pack quite a back-emf wallop if not corrected by its diode.

[searcherrr]

Originally Posted by 12Ounce

Have you tried disconnecting the ac clutch coil? Its a large coil ... would pack quite a back-emf wallop if not corrected by its diode.

Thanks Selectron. Affirmative. I will teste HOT ECT when I get the van back hopefully today or tomorrow. That exhaust shop is taking forever. ...and yes I am hoping the CCRM resolves everything.

12Ounce - Would the ac clutch coil cause back-emf even if the ac is OFF?

Selectron - Guess I have to go reread your explanation, but I'm confused how unplugging the fans and then NOT seeing the stumble/attempt stall ruled out the fans themselves. I have to run, but I'll reread your explanation in a lil while.

Thanks for hanging with me everyone.