Engine will not crank...

[86VickyLX]

I had some free time today, so I pulled the upper intake, and started my search for the electrical gremlin which is plaguing me.


Turns out the car doesn't have a Ground Strap going from the passenger side head, to the PS Fender under the hood hinge. It appears that it never had one from the factory either, as the hole in the ground point tab has never been tapped.

The only exposed hot wires I could find where on the O2 Sensor wiring harness, which has several places were the wiring is exposed, and was also only grounded on the trans to engine mounting bolt, and not on the DS lower intake and PS head, like the correct factory harness.

The O2 harness is hacked beyond repair, so I pulled the entire harness from my parts car, along with the Ground Strap, and I am gonna Install both of them tomorrow, making sure to ground everything at the correct factory points.

Is the ground strap really required to be able to crank the engine?

I'm glad I have my Unmolested Beige Box to go off of as a reference, or I would really be lost in this boxes engine bay.

I really hope this fixes the problem.

You need good grounds for good starts mang. Vicky won't start if the terminals are corroded, it'll click and then everything will shut off. Establish good grounds first. Then go from there.

[LTDMan83]

You need good grounds for good starts mang. Vicky won't start if the terminals are corroded, it'll click and then everything will shut off. Establish good grounds first. Then go from there.

Yes, I know this....

My terminals are brand new. The problem is finding all the ground points, I have been through and cleaned at least 6 ground points thus far, to no avail.

[packman]

The first thing I replaced on my mom's CV was the starter and the relay. I just recently replaced the starter on my Ranger; it was doing the same thing that your car is doing. I used to have to tap it with a hammer to get it going again.


Packman

[LTDMan83]

The first thing I replaced on my mom's CV was the starter and the relay. I just recently replaced the starter on my Ranger; it was doing the same thing that your car is doing. I used to have to tap it with a hammer to get it going again.


Packman

I've already replaced the entire cranking system mang. From the Ignition Switch to the Starter. Nothing more for me to replace at this point.

[packman]

I've already replaced the entire cranking system mang. From the Ignition Switch to the Starter. Nothing more for me to replace at this point.

And the problem still persists?


Packman

[LTDMan83]

And the problem still persists?


Packman

Sadly, Depressingly, Hopelessly......Yes.


That's why I'm going through all the wiring, and ground points in the engine bay now.

[packman]

Sadly, Depressingly, Hopelessly......Yes.


That's why I'm going through all the wiring, and ground points in the engine bay now.

I hate electrical work. At least this is the project car, so you don't have to rush to get it running the next day.


Packman

[85crownHPP]

I know this will sound insignifigantly minor and stupid, but i only mention it becuase installing and different (dead) battery makes a difference -
Have you been cleaning the inside of the terminal clamps and the outside of the terminals with an actual battery terminal brush? Even if terminals look clean they can still be scummy enough to not get a good crank. Those terminals need a lot of clean area to deliver all those cranking amps - putting in the old battery and getting results makes me think maybe you're getting a better connection with that battery.

Also keep in mind its possible to get a defective new battery, and defective new cables. Where did you get your cables from?? I had an intermittant no-start problem I only figured out when my "new" discount auto positive battery cable pulled out of the crimped eyelet end in my hand.

Do you have a volt meter? if so, hook it up to the battery and watch it while you crank. If the connections are clean, and the voltage drops below 10.5 or so, you have a bad (or drained) battery. If not, continue this test hooking up the + and - leads to different hots and different ground points, this should help narrow down whats good and whats not and should point out a bad connection/cable. I found a bad replacement terminal-to-bare-wire connection by doing this by 1st probing onto the battery terminal itself (held 12 volts) then probing the clamp (held 12) them probing the wire just behind the clamp (dropped to 2 volts).

[89LincolnTWNcar]

OMG I just thought of something... There is a ground wire that comes out of the harness at the back of the engine, that the oxygen sensors are hooked into. I am having the same problem and I think I left that ground loosely connected back there, and that may be the problem with yours as well. On a stock towncar, it grounds on the drivers' side rear lower intake bolt with a nut on top of another nut. Check that maybe?

[86VickyLX]

Volt meter is a good idea, I use my volt gauge to check voltage. It reads 12 sometimes yet wont crank. This is the time where I take off the cables and clean the terminals, which I just recently did. Even if I would jump the car, it would crank normally for a few seconds, then nothing. The jumper box would be green, which tells me that there are bad connections between starter and cables. Clean them again.

[91waggin]

Volt meter is a good idea, I use my volt gauge to check voltage. It reads 12 sometimes yet wont crank. This is the time where I take off the cables and clean the terminals, which I just recently did. Even if I would jump the car, it would crank normally for a few seconds, then nothing. The jumper box would be green, which tells me that there are bad connections between starter and cables. Clean them again.

:stfu1: Do you not get that he's replaced the entire cranking system yet? Do you not think that he hasn't already thought of that and done it a dozen times? The problem is a lot more serious than a halfwit and a battery brush will be able to fix.

[LTDMan83]

^ Thank You.

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Guys, Seriously, if the problem was as simple as corroded battery cables/terminals, this post would have never been made. I've been driving boxes for around 7 years now, I learned basic maintenance a long time ago. Yes, I do have a battery brush, how else would I be cleaning the terminals?... My evil eye powers are not yet strong enough to strip corrosion from metal, unfortunately.

The fact that the cable gets really hot means something is shorting directly to ground as soon as you put power to it, or there is really high resistance in the cable that's getting hot.

You say it cranks when you have a good donor battery, which says to me that, while most of the current is going directly to ground, there is enough forward voltage (for a few seconds) to actually crank the starter as well. It's as though there's a direct wire to the negative battery post in parallel with the starter. Make sure no hot wires are bare and touching the frame somewhere.

The original ground cable has 3 wires. One small to the ECM, one to the core support, and one to the engine block. There are also several cables from the back of the cylinder head to the firewall near the right side hood hinge. make sure all those are in place and in good shape. The ones at the back of the motor often get crudded up.

Do you have a volt meter? if so, hook it up to the battery and watch it while you crank. If the connections are clean, and the voltage drops below 10.5 or so, you have a bad (or drained) battery. If not, continue this test hooking up the + and - leads to different hots and different ground points, this should help narrow down whats good and whats not and should point out a bad connection/cable. I found a bad replacement terminal-to-bare-wire connection by doing this by 1st probing onto the battery terminal itself (held 12 volts) then probing the clamp (held 12) them probing the wire just behind the clamp (dropped to 2 volts).

OMG I just thought of something... There is a ground wire that comes out of the harness at the back of the engine, that the oxygen sensors are hooked into. I am having the same problem and I think I left that ground loosely connected back there, and that may be the problem with yours as well. On a stock towncar, it grounds on the drivers' side rear lower intake bolt with a nut on top of another nut. Check that maybe?

^ Examples of Good posts here, which are helping me out.

I do need a Volt Meter to start checking wiring, as I'm pretty much working off of just sight alone right now.

Thanks to 89LincolnTWNcar, for confirming for me that the factory correct O2 Harness does indeed ground on the DS rear of the lower intake, and the PS rear of the cylinder head. Enjoy that RSB btw...


Gonna finish up the rest of the work today, and hopefully I'll have a cranking engine by sunset.

[89LincolnTWNcar]

Thanks to 89LincolnTWNcar, for confirming for me that the factory correct O2 Harness does indeed ground on the DS rear of the lower intake, and the PS rear of the cylinder head. Enjoy that RSB btw...

Haha no problem mang, Oh I still have to install that RSB, gotta get on that hahah.

[LTDMan83]

UGHA!

Still not cranking right, even after all that work...:nonono:

I'm beginning to think that no one has ever had this much trouble getting their Box to crank.

I'm pretty much at the end of my rope with this, and am beginning to consider that I am gonna have to seek the help of a Professional Mechanic.

The only good thing that has come out of all this, is that I have become very familiar with ALL the wiring in the engine bay.

[89LincolnTWNcar]

We'll when I get to the end of my rope, I always find that the solution is something rediculously simple, like a fan wired to blow backwards, or no gas in the tank. just an thought...