Jaguar XK8 Alternator how to repair,. Symptoms, causes of failure, component numbers V171 XKR X100

[@benleone5800]

Hi Damian-I Fit the Denso LNC1800AA to the Jag yesterday. Not a job for the faint of heart. Top bolt was dinged by a previous power tool. Had to file the bolt to get the 10 mm wrench on. The connector fell apart in my hand, crumpled to bits. I ordered a new Denso Oval connector. TWO wires to that connector, green wire top, White wire under that. didnt realize there was three poles on that connector. So I need to verify orientation. The unit was Frozen to the bracket. I sprayed PB Blaster, and hammered the unit upward with a one foot two by 4. FINALLY it came loose. Removed the bracket, for the suppression module and the air cleaner.... PIA. Just all labor. Thank GOD the unit is now in place and the connector is on its way. So next is the soldering of the connector. Not much room in there, about only 3 inches off the harness. Wish me luck! Ill keep you posted. You Stay well! Thanks for getting back!!! God Bless! Ben

[@ODRModurol]

Ben, sounds like the car and alternator are putting up a real fight. Hope you have broken the back of the job now and putting it all back together goes more smoothly, regards Damian

[@benleone5800]

Based on my research the Suppression Module was for the high end stereo. I have a harmon Kardon stereo. I can always connect it later to the large positive on the Alternator , if I have radio noise. I put it all back in place the (suppressor and bracket). Hooked the ground to the case bolt on the Alternator where it was. Again..... Thank-you sooooo much for all your time trying to help me out !!!! You are indeed a special guy! Sometimes I call around for info, they say, A Jaguar! Good Luck! Have a great night!!!! Ben 😇

[@ODRModurol]

Ben, awesome!! Very glad you got it sorted out. An old Jag is no match for you, must be very satisfied. Now the car has your mark on it and owes you big time for its existence. Happy motoring or onwards to the next repair (we are driving Jags), regards Damian

[@benleone5800]

Hi Damian! Hope you are doing great! Here are some updates: The new Rebuilt Denso is holding the "Battery Not Charging" lamp on. Also The Voltage gauge is lit. I am trying to get my $$$ back from Eeuro parts. I ordered another Alternator from Welsh Jaguar. Hopefully this one will play nicer with the electronics. I was quite depressed as I spent a lot of time with this. I had to have the connector soldered in the end. Thank-you SO much for all the inspiration, sure needed it, if it was easy everyone would be doing it! I am hoping once I get the alternator right, the rest of my electrical woes will follow suit. The center console and heated seats are inoperative. I am praying here! Many Thanks again! Thanks for being there, for me to vent! I am going to get this done!!! Regards, Ben.

[@ODRModurol]

Ben, heard about aftermarket alternators not working with the rest of the system. Not sure why but it seems to happen. Hopefully, the other issues will clear with the new alternator. Keep us posted on developments, keep going you are a step closer, regards Damian

[@terryc8164]

Thanks for this one, useful info for when it eventually fails.

[@ODRModurol]

Terry, hopefully make things a bit easier and less expensive for owners to keep their car running, regards Damian

[@terryc8164]

Yes, and its much appreciated. Those alternators look really simple to sort out. Cheers!

[@ODRModurol]

Terry, yes and it worked in my case, regards Damian

[@gerardbooth40]

Smashing video Damian. I'm just back from a brilliant 800 mile trip to the Highlands of Scotland. The XK8 was faultless and averaged 29mpg overall despite a real mixture of driving. However, I've got a slight metallic rattling noise from the area around the serpentine belt. Can't quite decide if it's the tensioner, water pump or alternator, but she's going into her winter lay -up from 1st November, so I'm planning to strip down all the components on the front of the engine as well as replacing the plastic thermostat housing with the later metal one. I suspect it's the tensioner, but time will tell. No doubt I'll be swatting up using your earlier video guides before starting. Thanks for this and all the other maintenance guides. These plus Gary VanRemortel's 'Bible' on TTG are absolutely invaluable. Cheers!

[@ODRModurol]

Gerard, sounds like you are having lots of fun with your XK8. My guess would possibly the idler pulley. Would be interested to hear how you get on with your winter maintenance, we are always learning, regard Damian.

[@benleone5800]

Hi Damian! Just waiting on the Denso Oval Connector. Also ordered Crutchfield Accele Butt connectors Part # CR102ss-20. They include the Solder shrink tubing and weatherproofing glue all in one. The two pigtails come off the harness and there is less than 3 inches of wire, so this is going to be tight. I also bought a new Heat gun. Turns out the Green wire, is a GRAY wire. I am colored blind. Slate gray wire is the dash warning lamp (Top Connector). White wire. connector in the middle is Ignition B+. Bottom pole in the connector is NOT used. I am trying to verify this with the Jag Forum. Sometimes they can be helpful! Thank-you for supplying the initiative and fortitude for me to forge on, repairing this Gorgeous Coupe. I know you are in my corner. Ill let you know how things unfold here! many Thanks Again! Stay well and God Bless! Ben Leone

[@ODRModurol]

Ben, you are getting a real grip of the electrics. Please note all the wiring diagrams are easily and freely available via our website www.modurol.co.uk . You enthusiasm and get on with it attitude is very inspiring, keep up the good work, regards Damian

[@jonathanslade2358]

Thanks for that Damien, as always very helpful. I have taken out and sold the cabin filter on my XK8, after all it was just gathering dust. Cheers, Jon

[@ODRModurol]

Jon, thanks for the compliment. It like the filter joke😆😉👍, regards Damian

[@tiny19892]

Thank you so much. Top bloke

[@ODRModurol]

@tiny19892, thanks for your support, regards Damian

[@UdoIBress]

thanks for the interesting video. my xk8 is going into hibernation now. I'm going to put in new shock absorbers and strut mounts in the front. with your help (video) Greeting Udo

[@ODRModurol]

Udo, thanks for your support, my XK8 is also going to hibernate from next month. Lots a small jobs planned including a new headliner. Sorry, I haven't replace the shock absorbers or strut mount on my car only removed, painted and refitted. I did all that before I started the channel so haven't made any videos. TheJ aguar workshop manual will be very helpful. If I can help in some way I will try, good luck, regards Damian

[@richardsutton01]

The main problem I have found with alternator repair is when you need to replace the bearings because they become noisy and make a lot of whining noises. It's a reasonably common failing, perhaps as a result of the hot running. I don't know whether the Denso's fitted to our XK8s fall into this category but some models I have worked on require cutting of wires and then access to a really heavy duty soldering iron and some suitable copper collars to re-make the connections. Pulling/pressing the bearings out once the alternator is dismantled obviously requires a suitable puller and press but it is not technically difficult. Richard

[@ODRModurol]

Richard, good info. From what I have found these Denso alternators are mechanically reliable. Economically, if the bearing are suspect it’s probably worth investing in a complete reconditioned and tested unit. If the bearing are gone possibly needs brushes etc. Thanks for the input for your experience, regards Damian

[@garyvanremortel5218]

Damian, thanks for reminding me of the need to update the XK8 bible to include my recent alternator adventure. Easy replace job from top. My backlighting began flickering out at 150Kmi, so I replaced with a $240 reman. Latest rev bible out on John's website.

[@ODRModurol]

Gary, thanks for the feedback and sharing your experience with alternators. Will take a look at your new entry in the XK8 Bible, regards Damian

[@daven6357]

Thanks Damian, very handy as I’d recently acquired a Denso replacement. Had been experiencing ‘battery not charging’ errors, also some ABS sporadic errors. Found your explanation helpful (along with jagvettes!) Managed all from up top tho’ the cooling cowling had to be removed/replaced from below - took the opportunity to changeout abs sensors while at it - don’t think there was ought wrong with them tho’! Trust all good there, cheers from Aus. Dave

[@ODRModurol]

Dave N, All good here. Thank you very much for the feedback. Glad it helped in some small way all the way over in Aus. Much appreciate your long distance message, regards Damian

[@jamesfrost4323]

Great video, on a different subject just completed cam chain tensioners replacement, everything good except when parking my car on full lock both sides the revs drop and engine stalls. Checked steering fluid all good battery alternator all check good. Car idles nicely just when up to running temperature on full lock it stalls. Is there a way of speeding up the idle via a adjustment screw as it only needs 75-100 revs more. I searched around the throttle body area but cannot find a adjustment screw for idle. Any help Damian would be great. Thanks James.

[@ODRModurol]

James, well changing the timing gear, another one saved from the crusher. Sorry there isn't an idle adjustment screw. Its an electronic throttle controlled by the ECU. "At idle, the ECM controls engine speed using the restricted throttle valve movement available between the mechanical guard (open limit) and a factory set stop on the dc motor drive gear (closed limit)". Suggest the only thing left that might be worth investigating is the air intake. Might just be an air leak on your intake elbow which has effected your mixture. This is a bigger problem at idle speed than when its running down the road. The fuel mixture might not be quite good enough to keep it running with the additional load at full lock. Hope that helps, please let us know how you end up fixing the issue, regards Damian

[@gimpsunlimited2505]

on my second replacement. Living in Phoenix, I believe these things just get cooked unless you are traveling faster than a certain amount of speed. Therefore, stop n go traffic when the pavement temperature is probably 150f just cooks them

[@ODRModurol]

GIMPS Unlimited, can fully understand why they might cook in hot climates without the car moving. No air flow due to the ducting. Thanks for your sharing your experience, regards Damian

[@benleone5800]

Hi Damian-tried to pull that alternator today. Small harness going to alt has a stray red wire not connected to anything, the other wire to the small nut on the Alt. There is a Green and white wire going to the connector plug. (Green on top) But the New Denso has three terminals. Of course after 26 yrs the connector is frozen in the alternator. had to break it out. Any ideas???? This job turned sour quick. Thank-you! Ben

[@ODRModurol]

Ben, would be worth checking the wiring diagram for clues, regards Damian

[@benleone5800]

Hi Damian, Hope you are well! Would needing an alternator make my windows go haywire? Driver window goes down on door opening. Window resets useless. Tried to hard reset. No go. Alt gauge running to the left about 9 Volts not straight up. Thanks! Ben

[@ODRModurol]

Ben, 9 volts on battery gauge is definitely flagging an electrical issue. Low volts will probably confuse the door module. When I had an alternator issue it was pushing circa 15 volts rather than low volts. Might suggest charging the battery, check the volt meter gauge and trying the windows without the engine running. This would help to identify alternator or battery issue. But might be a problem with both. Please note some motor factors/spares shops will test your battery and alternator for free in the UK. I think the volt meter actually reads the true volts until the engine is running. Hope that helps, please let us know how you get on, regards Damian

[@benleone5800]

For some reason the suppression module was disconnected from the Positive. Do I need that? The red wire would go to the main positive cable at the Alternator.... my guess. As eyelet was larger. Ill leave it disconnected ,as it was. Thanks again my good man! If I didn't LOVE this stunning Coupe as much as I do, I would NEVER do this. Just no car quite like it!!!! Hands Down!!! Talk soonest!

[@ODRModurol]

Ben, Not sure why the suppression module was disconnected, assume you need it to reduce radio interference. Looking at the wiring diagrams, the wiring altered over the different generations of the car, both the wire colours and its operation (no suppressor shown on later models). Sorry couldn't be much help. Hope you have got your car up and running, agree it is a labour of love, regards Damian