must hold key in start position for car to run

[1cent]

My dad replaced the starter on his 1988 mark 7, the car will not stay running unless he holds the key in the start position? I have an another question regarding the starter relay on my 1988 mark 7 how do you hook up the wiring on the starter relay.

Thanks :confused:

[Drake_tr7]

Inertia switch in trunk is tripped. Push the reset button on a small black box next to the left trunk hindge;) There are other things that could be wrong but thats the first thing to check.

[gadget73]

Inertia switch won't do that. If its tripped, the fuel pump won't run at all. If I had to guess, either your igntion switch is shot, or the TFI module is half dead, and only working on the start power circuit. Start with the ignition switch, they're a known problem and a risk of fire.

[Bluegrass]

Recheck the leads stack at the start relay if it was taken apart, for an error in placement.
Next, the TFI could be the problem because it has a start and run function that is seperated by the ignition switch positions.

[Drake_tr7]

I must admit Gadget, I've never actually seen a Mark VII do that including my own. But back then I was in the buisness and driving a wrecker and saw that exact trick happen many times to other Ford models, most common being the Escort (ugh cooties !) A light tap in the ass (or concieveably dropping it too hard onto a jackstand) Thats what led to my statement, not, I admit, cracking the books and doing the research.
So spank me if I'm wrong, I stand corrected:o and as usual BG is on target.
That would lead me to surmise that the enemy ignition switch was probably the culprit in the origonal starting problem in the first place.:dunno:

[Artbaileyjr]

If the ignition switch has not been changed in your pre '90 Ford product, start there.

Art

[demonswede]

coil resistor on the firewall gives exactly the described situation.

Do we hav such resistors on our mark VIIs???

[gadget73]

No. They stopped using those when the EEC III system went away after 1983. Duraspark used a resistor, TFI ignition does not.

[Lee Joffe]

Dead TFI module has those exact simptoms.

[1cent]

how do you hook up the starter relay on a 88 mark 7.

Thanks!

[gadget73]

The same way the old one came off :)

small wire to the S terminal, cable to the starter on one side, everything else on the other side.

[LSRX101]

Looking at your original post:
It sounds like you have the large battery and starter cables connected properly as well as the "trigger" wire from the ignition switch. (It cranks when the key is turned and stops when released).

Make sure ALL of the OTHER wires are connected to the same terminal on the relay as the battery cable. There should only be ONE wire/cable to the starter on the other large relay terminal.

If the relay was replaced to try and cure the "runs until the key is released" concern, you are in the wrong area.

Aside from wiring breaks and other very uncommon problems, there are 2 things that commonly cause this:

- Bad ignition switch. This is the #1 cause of this concern in my own personal experience. It will often cause various other electrical anomalies before this particular failure happens, but not always. If it runs in the crank position and stops when I release the key, I zero in on the switch first.

I've been fooled a few times, but not very often by:
-Bad TFI module. As mentioned before, this is a common TFI failure mode. Others have explained HOW they fail.

For a "quick fix" you might want to consider replacing both. About $85 for "good" parts.
Diag beyond that via Internet Forum can get really involved and take days or weeks depending on.....

[1cent]

the starter was bad and the tfi was bad, my dad disconnected the starter relay for some reason and I am not sure how it was hooked up. I just want to make sure its hooked up correctly if its not hooked up correctly that could be one of the problems?


Thanks for all the help!

[gadget73]

Possibly. If one of the fuse links that happens to be one that feeds the igntion or computer or something is wired to the starter side of the relay, it will only have power in the start position.

[Magic Al]

First thing is change the ignition switch. Electrical part, not the key lock. http://www.thelincolnmarkviiclub.org/documents/tech/1984ignitionSwitch.pdf

Anyway, here's the wiring you're asking about: http://thelincolnmarkviiclub.org/Gallery/albums/album94/Start89EVTMfull.sized.jpg

I don't understand how the car can "run" w/ the key in the start position. Wouldn't the starter motor keep cranking / stay engaged also? If what you're saying is that it continues to run w/ the key held part-way toward start, then change your ignition switch.

[Hizhonor]

Regarding the "key lock / cylinder" ........ Just an FYI / Tip .....

I've seen some folks with keychains that weigh at least a pound with all the keys, hooks, rings and knick-knacks hanging off of them. This is the WORST thing you can do to the key switch. Keep the weight of the keychain to a minimum.

Heavy keychains put undo pressure on the internals of the cylinder which will, in time, screw up the alignment to the contacts. Just an observation.... your mileage may vary. ;)