I have been having a problem with my F-350 4x4 Crew Cab Manual truck. 1st. It all of a sudden started running very rough and no power. Appeared to only be right bank. Changed oil and that stopped but at the same time, I unplugged and replugged the wiring harness on that bank when my hearing device indicated only right bank misfiring.

Now all of a sudden the speedometer quits....jumps around violently and then goes to Zero. THen all of a sudden it will start working properly.

Then the batterys are dead...18 months old w/3 yr. free replacement so they shold be good..had checked, yes they are good...Recharged and the same thing happened the next moring.

Tried to recharge today with them connected for 2 hours...never recharged..so I pulled the battery cables, (This truck has two batteries). When I pulled the second ground wire, i noticed a sharp crack..so I checked and sure enough, there is a HUGE drain on the batteries...

I disconnected all my auxaliary items such as winch...strobes, etc...

Still have the huge drain.

Now when I connect, the cab buzzer for the glow plugs will not go off even though the glowplug relay is functoning properly, or at least is sounds like it is turning working properly.

Any body have any idea where to start looking.....

There is miles of wire...

Oh by the way...the draw is in excess of 10 amps as my multimeter kicks out and it is set to read up to 10 amps...

Thanks

 

Check your trailer wiring to start. Brake controller too if you have one.

 

the trouble with your speedo would be your VSS or vehicle speed sensor. this is located in your rear diff. change it.
as for the rough running have you check your UVCH? the wire harness under your valve covers?
mitch

 

Yes, rough running and one bank not firing could definately be the UVCH wiring. Unplug the harness one at a time (there are two on each head) and if it runs the same with it unplugged you have a problem under there.
It's fairly easy to replace. Pull the valve cover and unplug the old, plug in the new and I'd replace the valve cover gasket that doubles as the plug also.

Did this on my truck a while back when it was only running on 4 cylinders. Also while you have it apart put in some new Beru glowplugs.

 

Thanks for the replies.

I replaced all 4 wiring harnesses under the valve covers 45000 miles back when I replaced the injectors.

That problem was air in the system. For some reason, the filter was loose and had leaked out a bunch of oil. WHen I replaced it and changed the oil, the miss went away.

Worse problems have developed.

THere is a major short somewhere. It is in excess of 10 ams of drain as my multi-meter kicks out since it is set to max of 10 amps.

It is such a drain that the two batteries would not recharge when hooked to a good recharger for 2 hours.

I have traced it to either the left door switch or the buzzer that is warns of key left in ignition.

THe buzzer would not shut off and when it did, the drain stopped.

I just hate chasing wiring problems. They can be so aggrivating.

 

un hook the glow plug relay and see if that helps

 

This is turning into something completely different than I envisioned. Must have read over the gpr and buzzer part. Is it an XLT with a remote for the door locks?

 

sounds like glow plug relay not releasing. unhook all terminals and tape off the ends of the wires then see what happens.

If not that major short prob not easy to find.

 

What would the odds be that BOTH 1.5 yr old batteries on a 60 month warranty were BAD.....That was one of my problems.

QUESTION...
What is the amperage draw in parked engine off..doors closed mode?

I am drawing about 0.5 amps...is this high...I can't find any data that gives me this spec.

The Glow plug solenoid is fnctioning properly...

After replacing the batteries, when I started it up, it ran properly for 10 sec and then started doing the previous rough idle and the service light came on. Turned off...un did batteries and checked several circuits..restarted did the same but then it started running properly and lite went off..

I can't read codes with my OBDII reader as it is above the 8000 lb rating.

This truck is possessed!

 

The twitchy speedo could be VSS or the PSOM. PSOM is integral into the speedo and the cheap way to fix it is to buy another cluster and swap it in.

 

A Little success..

I figured out my rough running problem.
The external wiring for the rear two injectors on the drivers side had shorted out on the turbo housing and the wires were bare and twisted.

Where can I get a partial harness so I can splice in a new end. as the wires are bad right at the connector.

Once I get past this issue, I can then move to the speedo...
Will check the resistance on the sensor in the rear axle housing and go from there.

 

I found the Valve Cover Gasket Pigtails...They come in a set of 4 with 8" of pigtail to replace the prone to melt, distuct after hi miles originals.

Price is $52.95 plus shipping and handling from several places.

They also come as part of the O'Reilly Auto parts 7.3 valve cover gasket set for $75 per side...includes 2 pigtails and 2 UVC harnesses as well as the valve cover gasket.

Got the beast back on the road temporarily until the parts get here...

Interesting is the bare wire that is wrapped around the entire unit...that is what shorted out the injectors as the insulation hardened and fell off...
I assume that the wire is to shield the wiring....I would assume for RF.

 

I had a problem a while back when I had a bad battery. one battery had a short and was draining my other battery. I will try to find the link on mine and edit this post with it.

HERE IT IS: https://www.ford-trucks.com/forums/8...batteries.html

 

Did you find out the drain? Is everything SNAFU?

 

50 mA is the max draw. (.05 amps)
You have 10 times more draw than it should be.

Disconnect everything that isn't OEM electrical.

Hook up your meter and start pulling and replacing fuses while watching the meter for a drop. Let us know what you find.