LR3 Intermittent Starting Grounding Problem



I started having intermittent problems with starting (click but no starter motor running) and getting mysterious error warnings (limited gears, suspension, HDC, etc.) so at first I thought starter motor and promptly ordered one. Because the starter motor replacement process is so labour intensive, I decided to double check all the wiring associated with the starter circuit, especially the primary ground, which on my LR3 (4.0L V6) does not go directly to the engine block but to a stud which is through mounted via the passenger side fender North American Spec (NAS). Thus the starter motor ground is via this connection, NOT via the old direct to engine block as on my 1952 Chevrolet and many subsequent vehicles. I then followed the process described here to recondition my corroded electrical grounds on my 14 year old (2007 LR3 4.0L V6) machine.

Disconnect battery negative post, positive post, battery hold down bracket and remove the battery. Remove the positive cable from the “engine compartment fuse box” (front) and don’t lose the stainless nut! Remove bolt in front middle of “engine compartment fuse box” and move box out of the way as much as possible to access the negative cable body attachment stud and to also remove the acorn nut (13mm) and negative battery cable. Now you can remove the passenger side headlight assembly, which will enable you to access the sole Phillips sheet metal screw holding the fender flare/moulding on and to get your hands on the electrical connector to the antenna for the Tire Pressure Monitoring System (TPMS), which must also be disconnected. Before you start pulling gently but firmly on the outside fender flare/moulding to remove the flare/moulding, you must now remove all the pin-push connectors on the underside of the splash guard (fender liner), some of which also hold on the flare/moulding plus any screws (4) which are holding the splash guard in place. You’ll likely break most of the push-pin connectors like I did if this panel is original so make sure you have about 10 new ones on hand, and don’t forget the Phillips screws (2) holding the liner to the rest of the body (1 at each bottom end) or you may become apoplectic (APOP)! Once you are done sweating and swearing at your efforts to remove the liner, you’ll see the reason for doing it, the other side of the engine compartment main grounding stud. In my case the stud and its connections were somewhat corroded, so I wire brushed all and reconnected them, applying a generous coat of dielectric grease. I also ran a #4 stranded copper cable additional ground wire from the engine compartment stud to a stud on the intake manifold to double guarantee a good ground for the starter motor. I used my trusty 16 ton made in China hydraulic crimper to attach some 5/16 inch holed connectors to the cable, ensuring an excellent electrical connection.

Since this has only been done for about 8 hours, I’m not sure I’ve cured the problem, but after about a dozen starts there have been no problems…


Stud behind engine compartment fuse box (on fender toward firewall side) with primary battery ground (negative) cable removed


Centre is TPMS antenna connection (small grey connector) looking through headlight space after headlight removal


Behind fender splash shield, primary ground stud through fender from engine compartment with wires and acorn nut intact


View of fender flare, headlight removed and splash shield dropped (could/would not remove rear bottom sheet metal screw)

If I encounter any further problems (hope this is a FIX!) will update, I guess now I have a spare starter motor...

 

Guess I am glad I own the V8, starter replacement is easy. Even the primary ground from battery can be removed without taking the fuse box out.

The fender flare does not have come off to remove the liner, I have removed liners numerous times and they come out pretty quick and easy if you just remove the plastic push rivets and a couple screws.

FYI, that nut with multiple wires is not a primary ground, its on the frame forward the strut. It would be a large single cable.

 

Yes the starter motor on the V6 4.0L version requires the driver side exhaust manifold to be removed and of course the pesky EGR pipe from the same, plus you have to unbolt the catalytic/exhaust from said manifold, lots of opportunities to break something. Thanks about the fender flares, I'll remember that for next time (am sure there'll be a next time), just that the maintenance manual showed them coming off. On mine, the negative lead from the battery goes only to the fender stud I published in these photos, there is a short heavy cable that goes from the lower front passenger side of the engine block to a stud on the lower passenger side front fender (replaced at engine replacement time), one or two braided bare cables from the rear of the engine to the firewall. I'll look at a grounding drawing to see what it says, there may be a missing cable (I'm apparently the 4th owner) and I did add a #4 additional ground, so far about 35 starts with no hesitation or annoying fake error messages but as I've learned about these LR3s, electrical issues are part of the "magic" of ownership. Thanks for the heads up and will update if any new issues pop up!

 

Well, the problem reared its head again and this time it happened when it was really cold, had a shop replace the starter motor and battery. The starter motor was replaced after removing the front driveshaft to replace a pinion seal, thus getting at the starter pretty easily from underneath. The battery was tested and was only putting out 250 max CCA so threw in a 940 Amp CCA new one, the starter motor was a new rebuilt Denso from Rock Auto, so I'm sure there will be no more starting issues (especially at -30C).

 

That is when my starter was a total pain, when it was REALLY cold out. We had a brutal winter and it was not fun with a failing starter. With that said I also put a Denso rebuilt in (like yours, rebuilt BY Denso). I did open my new one up and inspect and found the solenoid contacts were cleaned but NOT replaced. I had a new solenoid contact kit and put those parts in. I am sure the rebuilt would have lasted a while, but now I know it will last as long as the original. On a side note, I sealed mine up a little with Reinzosil. I also created a "breather kit" but installed two hoses into the breather tubes on the starter and running them up into the engine bay battery compartment. Cause I am pretty sure what killed my starter was some deep water fun I did the summer prior.

 

SNIP...

I also have a new solenoid and starter rebuild kit, which I'll be installing on the old starter, but since I'm not driving through deep creeks and fording rivers anymore it probably isn't going to be necessary. I didn't ask what it took for the shop to get it going but the invoice did say it took about 15 attempts before it started so I'm thinking that there was something intermittent with the solenoid coil because you could hear the relay R102 (in Junction-box engine (P108) 303-14 Electronic Engine Controls) operate but the starter motor solenoid didn't operate, even after letting it sit overnight. New parts make me feel better about the long drive to visit family, not good to be stranded anywhere in the winter...