1998 cobra imrc actuator

mwolson

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Well, the unit is fully functional. What we have learned is that you can't use a battery charger as the power supply to test the IMRC actuator.

Basic automotive battery chargers are typically simply full-wave rectified AC, not a steady DC voltage. It is not a regulated power supply. So the battery charger was basically powering up and powering down the unit 120 times a second.

You have to use a well regulated >3A power supply or a charged car or motorcycle battery as a power supply to test the IMRC actuator.
 

98 svt

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The hunt continues huh Mark?
I've seen a few people in the Classifieds looking for an IMRC actuator, perhaps one of them has a broken one they would be willing to send you?
 

Norton 850

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I am trying to source new inner IMRC cables, so I have been doing some studying of this.

First thing I assume is that the actuator box is exactly the same for the Mark 8 and the Cobra. If that is the case, then the cable length won't matter since it is the length of the inner cable travel that matters. If you can route the cables in a convenient way, the Mark 8 unit should work just fine on a Cobra motor assuming all the clips are compatible.

Assuming you do want to shorten the Mark 8 cables, you would have to cut the stop off of the inner cable and remove the plastic clip. It looks like it would be very hard/impossible to remove the plastic clip from the end of the sheath. So you would have to cut out a section of the sheath in the middle and then somehow fabricate and swage a sheath coupler to put the sheath back together again. Then you would shorten the inner cable, replace the plastic clip and swage a stop on the end of the inner cable. Seems like a hard thing to do.

FYI, I have two companies working on replacement inner cable solutions for me. I will probably take a few weeks before I see what they can do. I will let you know when I get the results. We haven't talked price yet, but I am suspecting it won't be cheap.

I am surprised that no one has any bad IMRC actuators that need repair. I would have expected there are a bunch laying in boxes in garages.

Mark,
Curious if you were able to source new IMRC cables? My '97 threw the stuck IMRC code and as I was in process of cleaning, realized my right cable was snapped. This is probably why I was getting code. I've been looking online, but usually need to buy the IMRC's and actuator box to get the used cables. Would like to get a replacement cable so I can run your bench test before putting back in car. BTW, great write-up! thanks for any help you can give me.
 

mwolson

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I have been able to source replacement inner cables for the IMRC controllers. However, taking the innards of the IMRC controller apart is very labor intensive, so it will cost a lot to replace the cables.

The things I have not been able to source are the cable sheaths including the plastic clips hat hold the sheath to the bracket and the electrical connector that is soldered to the PCB. So be very careful with those parts of the IMRC controllers.

I have also sourced repair clips for the ends if they are broken. I can replace those clips without replacing the cables.

In your case, it will probably be cheaper to contact Racebronco2 here or on Modfords. He has an inventory of IMRC controllers that I have refurbished for him and he is willing to sell them. He hasn't told me what his pricing is, but I am pretty sure it will be cheaper than me having to dismantle yours. But you should either keep yours or sell it to me as a core so that it can eventually be rebuilt when we run out of used inventory.

FYI, I have now repaired a bunch of them and the most common failure is cold solder joints on the connector that causes the resistance in the sensing circuit to go way up as you jiggle the connector. Resoldering those joints is challenging even with the professional soldering station I have because the connector pins don't extend through the PCB very far. I suspect the subcontractor factory had difficulty soldering them in the first place which is why we are seeing so many failures as they age.
 

96GT226410

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I used a universal throttle clip for the cable end when mine broke. I got it at Advance Auto. It's been fine for a year so far.
20170915_144040.jpeg
20170915_144807.jpeg


Sent from my SM-N960U using the svtperformance.com mobile app
 

Norton 850

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I have been able to source replacement inner cables for the IMRC controllers. However, taking the innards of the IMRC controller apart is very labor intensive, so it will cost a lot to replace the cables.

The things I have not been able to source are the cable sheaths including the plastic clips hat hold the sheath to the bracket and the electrical connector that is soldered to the PCB. So be very careful with those parts of the IMRC controllers.

I have also sourced repair clips for the ends if they are broken. I can replace those clips without replacing the cables.

In your case, it will probably be cheaper to contact Racebronco2 here or on Modfords. He has an inventory of IMRC controllers that I have refurbished for him and he is willing to sell them. He hasn't told me what his pricing is, but I am pretty sure it will be cheaper than me having to dismantle yours. But you should either keep yours or sell it to me as a core so that it can eventually be rebuilt when we run out of used inventory.

FYI, I have now repaired a bunch of them and the most common failure is cold solder joints on the connector that causes the resistance in the sensing circuit to go way up as you jiggle the connector. Resoldering those joints is challenging even with the professional soldering station I have because the connector pins don't extend through the PCB very far. I suspect the subcontractor factory had difficulty soldering them in the first place which is why we are seeing so many failures as they age.
Thanks, I will contact Racebronco2 about purchasing an IMRC controller. It's probably the quickest way for me to get my ride back on the road and out of my Father-in-law's garage! Unfortunately for me, it was the cable that broke, and that break was close to the controller box.
 

mwolson

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If you mean the sheath that broke, that is too bad. I have a couple of spares, so I can still repair it. So hang on to it or sell it to me or Racebronco2.
 

Norton 850

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If you mean the sheath that broke, that is too bad. I have a couple of spares, so I can still repair it. So hang on to it or sell it to me or Racebronco2.
the sheath was intact, cable inside sheath was broken. So everything looked good as I detached actuator, but then cable completely slipped out of sheathing. Then realized 4 inch section of cable was still attached to Actuator motor where it snapped.
 

scottydsntknow

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Read through this and understand why it sucks but... I dunno a lot of effort when deleting the IMRCs is a good option and works well. Or just swap to C heads but definitely killing a fly with a sledge going that route if that's the only reason.
 

mwolson

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That's pretty strange that it would snap like that. Very bizarre. But it is salvageable, so don't throw it away...
 

Tillerman77

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I have been able to source replacement inner cables for the IMRC controllers. However, taking the innards of the IMRC controller apart is very labor intensive, so it will cost a lot to replace the cables.

The things I have not been able to source are the cable sheaths including the plastic clips hat hold the sheath to the bracket and the electrical connector that is soldered to the PCB. So be very careful with those parts of the IMRC controllers.

I have also sourced repair clips for the ends if they are broken. I can replace those clips without replacing the cables.

In your case, it will probably be cheaper to contact Racebronco2 here or on Modfords. He has an inventory of IMRC controllers that I have refurbished for him and he is willing to sell them. He hasn't told me what his pricing is, but I am pretty sure it will be cheaper than me having to dismantle yours. But you should either keep yours or sell it to me as a core so that it can eventually be rebuilt when we run out of used inventory.

FYI, I have now repaired a bunch of them and the most common failure is cold solder joints on the connector that causes the resistance in the sensing circuit to go way up as you jiggle the connector. Resoldering those joints is challenging even with the professional soldering station I have because the connector pins don't extend through the PCB very far. I suspect the subcontractor factory had difficulty soldering them in the first place which is why we are seeing so many failures as they age.
Mark,
Does Racebronco2 now have both the Lincoln and the Cobra IMRC actuators? I don't need one now, but the last time I had checked with him in 2016, he only had the Lincoln actuators. As I recall the controller box is the same, but the cable lengths are different for the 2 applications.
 

98 svt

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I have refurbished a number of both for him this year, but most of them were the Cobra length ones.

Mark, do you happen to know the length of the cables, from where they protrude out of the actuator box, to the end of the cables for the Lincoln/Cobra cables? I have a complete box/cable setup somewhere, but cant remember if it was Lincoln or Cobra.
 

mwolson

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I don't have any Lincoln IMRC controllers, but my Cobra parts units have the following measurements:

Short side sheath length = 16"
Short side cable length with the cable pulled all the way out = 18.75"
Long side sheath length = 18.5"
Long side cable length with the cable pulled all the way out = 21"

I should have measured one of the Lincoln units when I had them, but I didn't...
 

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