I want to know if you can swap the alternator from a 2003 4.2 STR into a 2000 XKR 4.0. I believe the 4.2 is higher amp 140 vs. 120 on the XKR. I need to know if the fitment will be correct for the wiring harness and mounting bolts.

Hopefully, Someone has already attempted this and can provide some feedback.

Thanks!

 

I can tell you I put a 200 amp alt in my 2001 xkr after thw stock one experiences a thermonuclear meltdown. I posted the info in teh xkr forum a search for 200 amp should get you there. Been working flawlessly since

 

OK Thanks SlowPoke. Before I spend the money I would like to know if the Alt from the 4.2 (2003 STR) will work. The 2003 STR is my current Project and is currently down for Head Gasket replacement anyway. Now the XKR is down. Battery Keeps draining not recharing at all. If possible, I can save some money now and upgrade later.

 

Have tried it some time ago, and it will not work as the signaling to inform the on board ECUs between the 4.0 and 4.2 is different. Maybe you could get 4.2 alternator to work if you could swap the electronics somehow, never tried that though.

 

Thanks Avos that is the answer I was looking for. I guess I'm going to have to bite the bullit and get a new alternator.

Is upgeading the alternator to a higher amp going to add any value. This is in regards to SlowPokes upgrade to a 200 amp alternator. If I understand the description of the "Generator" from the JTIS manual, it explains there is a protective component that keeps the current stable like a suppresor. This keeps the output current from getting too high. Is this true and what is too high? Anyone with the knowledge please comment on this.

Thanks Again,

 

I just checked with Rock Auto. The highest amperage alternator they list is 140. Where does the 200 amp come from (and which of our cars actually needs it)?

 

Need is questionable. If you plan on doing any stereo upgrades or intercooler fans. The additional draw of these items may require it. In my experience with other vehicles is that a 130 amp or so alternator has been marginal with minimal extra electrical draw. 200 amp is also not so ridiculous an upgrade that Ive noticed any negative effects on alternator or battery life. For me iI needed an alternator and for under a $200 investment for the 200 amp it was worth a shot. So far so good. The company on Ebay was eagle auto electric. Ive dealt with them before with good success. It was also real easy to change on my 2001 xkr.

 

So as it turns out my alternator is good afterall, no swap needed. I was reading another thread where someone had mounted an after market amp and ran a separate ground causing the dead battery or no-charge scenario. So I got to thinking, after checking for an aftermarket amp and coming up empty handed. There is an aftermarket kill/anti-theft switch installed near the driver side of the center console. When I pressed this button before the antennae would lower. I though that's all it did. However, after figuring out the true function of this switch I'm a much happer owner

 

CONGRATS!!!!

It's always a morale boost when any of us solves a problem and is back on the road again.