Hi guys, my name is Roger. I have a 2006 Jag S-Type 3.0L and I had a gearbox fault light that came on and left, but if I push down the gas pedal, I will get Restricted Performance indication. When I went to start it the next morning, all I got was a click. I tried charging the battery and changing it to a new one, but it didn't help. There wasn't enough amperage to the starter, so I ran a piece of #10 wire from the battery to the starter and it started. I have checked the two mega-fuses in the luggage compartment, and they are good. I don't want to drive my car with a wire underneath my car. Can anyone help me figure out what is wrong?

 

Pretty much has to be a power or ground so find each, clean them up and should be good.

You can find a fair few by eye or check the workshop manual / electrical guide (free on here or JagRepair.com - Jaguar Repair Information Resource).

 

Wiring diagrams are here, scroll down to fig. 2.1 for the starter:

http://www.jagrepair.com/images/Auto...cal-2005on.pdf


I will readily admit I am completely confused by your #10 jumper wire. Where exactly on the starter did you connect it?

Did you connect it to the big terminal with the two big red wires on it, ST6 in the wiring diagram? This is the unswitched battery feed to the starter. If everything is in good condition, you should always have 12V available here. Those are big wires that handle a LOT of current. Note the megafuse for this circuit is rated at 450 amps. The heavy load of the starter would have smoked a 10 gauge wire almost instantly, so I'm thinking it couldn't have been connected there.

Or did you connect the 10 gauge wire to the smaller terminal ST5? This is the control circuit for the starter, and is protected by a 5A fuse, so 10 gauge wire could easily handle that.

From the Too Late To Be Much Use department, if the jumper was connected to the small terminal ST5, you could have simply run a short jumper from ST6, as battery power is always available there if the starter megafuse is intact.

Still assuming (Danger! Danger!) you had connected the jumper to ST6, there are two fuses and one relay to be checked in that circuit.

To energize the start relay (R20 in the Front Power Distribution Box), check fuse F1 in the Primary Power Distribution Box, located to the right of the US passenger footwell.

To actually supply the power that energizes the starter control circuit (at the small ST5 terminal on the starter), check fuse F27 in the Front Power Distribution Box.

If those fuses check good, suspect the starter relay R20 in the Front Power Distribution Box. The easiest way to check is to swap R20 with a known good relay and see if the problem follows. All of those relays in the Front Power Distribution Box look pretty important, so don't rob one of those. Probably the best one to rob is for the cigar lighter, relay R1 in the Primary Power Distribution Box. Remember, that's the box next to the US passenger footwell. Turn on the ignition and make sure the lighter works, so you'd know that relay is good. If so, swap this known-good relay with suspect relay R20 under the hood and see what happens.

 

A friend of mine has a 2007 3.0L that exhibited the "no-crank" phenomenom intermittently. Sometimes crank and start, sometimes just hot, dark and silent. If I recall correctly, part of the problem was it's selectivity in exhibiting the problem: It was his wife's car and generally would not start for her. She'd call and complain, he'd go to where she was, insert key, twist.."V'rooom!" Whether he then looked quizzically at her (as I'd have done) in the vein of "did you try this?" and ended up lodging on the sofa or not remains a mystery. Eventually, he got the car to exhibit the problem in 1st person and spent a few weeks troubleshooting it. The final solution was the fitment of a new starter.

So it could be that although it started after you fit the jumper wire, it is possible that your time could've been as well spent carving birds. Stranger things have happened.