Always in Overdrive...problem

[Northpole]

I wanted to summarize what I can do to fix this problem.
I hope you guys will help, I know of the search function here but not for this problem.
My 1995 Mark VIII goes always all the way into overdrive when driving, how can I turn the overdrive off?

- Is there a special fuse for overdrive?
- The wire from the contact in the shiftstick, can be broken - what is the best way to check that?
- Any other possible solutions?

THANKS!

 

[k9t8m]

you have a 95 right? the little black button under the shifter button toggles overdrive on\off.

 

[slowmkviii]

being a GEN 1 thy do have problems with the wires braking in the under the shifter
Gen 2s dont have this problem

 

[95MkViii]

i think he wants to find a way to permanently turn off O/D...

overdrive sucks in these cars. at least with the factory tune. at 35 40 im already in O/D.... my mark dose weird things in O/D car sputters sometimes and in O/D when i let off the accelerator the car jumps..... only happens in O/D

 

[Northpole]

i think he wants to find a way to permanently turn off O/D...

Thanks, but no. I just want to be able to turn it off, not permanently.

overdrive sucks in these cars. at least with the factory tune. at 35 40 im already in O/D.... my mark dose weird things in O/D car sputters sometimes and in O/D when i let off the accelerator the car jumps..... only happens in O/D

I agree, mine does the same....but only in O/D.

 

[Northpole]

being a GEN 1 thy do have problems with the wires braking in the under the shifter
Gen 2s dont have this problem

Thanks, yes could be wire problem, can anyone help me troubleshooting this? I.e how to find out if it is wire problem and how to fix it?

Does the cruise control have a special fuse?

 

[chris2523]

carefully remove the shifter. there is a clip in the shifter handle you can pull out. then you just pull up on the shifter. then check the wiring underneath for any breaks.

 

[95MkViii]

I agree, mine does the same....but only in O/D.

yep only in O/D

 

[Northpole]

carefully remove the shifter. there is a clip in the shifter handle you can pull out. then you just pull up on the shifter. then check the wiring underneath for any breaks.

Thanks, I did check the small wires and they seem to be okay. So what would then be the next step? Where does these wires go to? I would like to check the wires all the way to see if they are broken anywhere.

I also have occasionally speedometer failure, could that be the VSS or the wire to it? Is it easy to check?
THANKS!

 

[slowmkviii]

Check to see if the O/D button itself works

 

[SwedishMark]

i think he wants to find a way to permanently turn off O/D...

overdrive sucks in these cars. at least with the factory tune. at 35 40 im already in O/D.... my mark dose weird things in O/D car sputters sometimes and in O/D when i let off the accelerator the car jumps..... only happens in O/D

I have that too in the spare parts Mark Viii I just bought.
Happens when I'm in a cruise speed, lift off the throttle and then when I press it down again there's a shutter in the whole car and then there's nothing.
Havn't tested if it's only in O/D though. Have to try that.

 

[Northpole]

Check to see if the O/D button itself works

Good point, I was just checking the wires today and was trying to check the button. But how can I check it?

 

[marked8]

There is an article complete with pics in the tech section.

 

[Northpole]

There is an article complete with pics in the tech section.

Yes I know, but that one does not show how to check if the button itself is okay, i.e. how to check the button, just how to replace it. (a good article)

 

[unity]

A ohm meter on the leads maybe?