97 mountaineer 5.0 manual control heat

[monty98]

I've looked as researched before but seem unable find this time.

I have issues with the fuze #10 blowing & have thread about trying find cause already but haven't had success. Haven't had much time to search for cause though.. Speed control & overhead console plus the blend door actuator are on this one. I'm investing in a ton of 7.5 fuses to hopefully get me through winter unless cause is found. However, wondering about what is hopefully an easier to resolve problem.

Issue. The directional controls & fan settings work fine. Heater blowing full hot no matter setting on the hot/cold dial. Then it just started blowing only cold air...discovered fuse had blown again. I've replaced the fuse again & get heat but no temp control turning the knob--it is furnace heat even if turned to cold. When I replaced the actuator earlier this year door seemed fine. Is this likely a blend door problem or issue with the actual manual control or ? Is there a way to narrow down the problem?

If there a thread already just point me to it.

Thanks

 

[410Fortune]

Hey!! okay lets try to fix this
Fuse 10 you say has speed control, ovhd console, and blend door.
Your hot / cold mixing has an issue, sometimes only hot, sometimes only cold at this time the fuse is always blown, Replace fuse and the bled door starts working again.
Already replaced the actuator once

Your truck has the manual temp controller not the electronic group, correct?

Let me look see if I can find wiring diagram of circuits for fuse #10 on 97 sploder...
First off correct me if any of my info is wrong

So I have one question, does the fuse blow when you try to change temp?

If so that points to issue with the HVAC controls/blend door NOT the overhead console or speed control

 

[monty98]

Yes, you have the situation.
Yes, it is manual control knobs.

I have not noticed what triggers the fuse to blow. Will try to pay close attention going forward. It did seem related to the upper console but I have not used that as the display is not functional due to the typical problem here. Haven't fixed it yet. Might rob the upper out of my retired 98 until do the console fix.

Next time I take the suv out will see if turning the knobs triggers the fuse to blow. I don't think it is though as don't usually use that knob. When it was hot out & using AC just always leave on full cold so didn't notice.

I did have to replace the speed control buttons as they were terribly worn. I don't use speed control so don't notice if/when that becomes non functional.

There is a code for a problem with the ignition switch
GEM DTC B1352===Code: B1352 - Ignition key in circuit fault
so wonder if that might be related to the fuse blowing. Might have to replace that but then door keys won't match???
Interesting is my 98 has the same code but has never had any issues in 11 years owning it.

Thanks for any pointers. Hopefully, answered your questions

 

[410Fortune]

Can you remove the overhead console or at least unplug the wiring to it?
Your ovhd console may have a dead short?
One of these circuits has a dead short, that we know

B1352 means the gem module has detected that the key in/ door open circuit has an issue. Does your truck chime when you leave the key in the ignition and open the drivers door?

Yes finding out exactly when the fuse blows is very helpful = triggered! like a social justice warrior!
Otherwise we just need to eliminate circuits as the possible source.
blend door, ovhd console, speed control circuits are in question

Its funny the fuse you have that blows is attached to the criuse control buttons you replaced, the ovhd console that is out and the blend door motor you replaced.. only one thing left to replace

 

[monty98]

Thanks for your replies. Helping me focus!

When key in ignition & drivers door opened it does chime.

Haven't disconnected overhead yet as other winter prep stuff do. Don't know if makes difference the lights work on the overhead console just not the display. I had removed the console past & cleaned & looked at everything, hooking everything back up. But it could be dead short display itself triggers it. Seems like it would immediately trigger the fuse to blow though.

The fuse works for awhile. So maybe it is the ignition switch or continuing issue speed control wiring. If I remember correctly, did have an issue & had to open it all back up when put the controls in as they didn't work, .like some sort of short with something. So thinking concentrate inside there. Might start disconnecting the speed control since don't use it anyway. Will see about new ignition switch when in there. Just seemed a bit more complicated. At least 97 doesn't have a chip key!

 

[410Fortune]

Don't worry about the new lock cylinder that code does not mean much, just that the GEM detected an issue with the key in ignition /door open circuit at one time I do not think its related to your blowing fuse.
Focus on the speed control buttons, sounds fishy

 

[monty98]

Does it matter that the ignition code keeps coming back? I've cleared codes several times (FORscan) in process fixing/clearing abs sensor issues.

Electrical gremlins not my favorite things.

Will try open it up later this week & able to identify something.

 

[410Fortune]

well somewhere between the ignition lock cylinder and the drivers door master switch there is a wire that talks to the GEM module for the ignition "key in" circuit
Something is fishy in that wiring if that code keeps coming back
I would fix the blowing fuse issue first then worry about this since the door chime is working and the GEM module code is only a code somewhere in memory does not effect the functions of the truck
Maybe if the fuse issue is fixed the code might disappear? We need the wiring schematics for the fuse in question to be sure

 

[monty98]

Sometimes should just leave well enough alone. Full heat better than no heat! I was trying everything could to get fuse to blow & it wasn't. But decided to see if the actuator was working at all. I pulled it out & harness connected fiddled with knobs trying get it to turn. No motion noticed (marked location so adjust back as necessary). So decided try the old OEM ford one as had taken apart/cleaned... there is no visible damage to wheels/cogs. Well somewhere along the way the fuse blew! So think the spot concentrate is down at the actuator. So went to put the "new after market" one back in & no way it was going to drop in...Puzzled. Then noticed it had moved less 1/4" but enough that due shape & all down there just no way to try to use it as lever get the door adjusted same. So put OEM one back in as it just happened to go right in. Don't seem to have heat again (door position must be off & since fuse blows have no chance to move it at all!). Will take the after market one apart & adjust the position & try get it back in as the OEM doesn't seem to be helping the situation at all.

Just not sure what about an actuator would make the fuse blow. Not noticing any damage to the wiring as far as can trace it up into the dash. So thinking I should test the wire harness connector to see if things working ok? Just not sure what pins... Any ideas?

I don't want to keep buying actuators if something is causing the circuits to blow inside them. Maybe the new one just doesn't have enough strength to turn the door. But when it out & not needing turn anything but itself it wasn't moving a whole lot (but it did move some). Unfortunately, the person selling with the warranty is now disappeared so need to buy a new one. Thinking possibly junk yard used/tested OEM so not have much invested if it dies.

Might have to jerry rig something to fit in the pin hole so can attach arm to it & manually turn/position it (maybe the arm from the old one). On my Chevy I'm using vice grips on the arm to change hot/cold. It works if not pretty!

 

[donalds]

Ill bet @J_C has the wiring diagrams and some input
The knows his shi™