1. Our 1998 Xj8 V.P. Had a accident Not much damage after we got it back the alternator want out so we replaced it with a OEM alternator,last Friday evening driving it home ,all the light came ,So we stop ,But the car would not start back up ,so we charged the battery system and the next day driving it home ,order a new alternator , install it , only to still have the light on ,So I replaced the battery ,can someone tell me the location on the automobile where the suppression Module on our Auto ?

 

Suppression module?

Have you had that alternator checked?
Be sure to check the connectors on the alternator, that they are not damaged in any way. Make sure the connector isn't cracked and arcing. This can cause either the voltage regulator to improperly charge or burn it out. Check your battery cables, ..any corrosion will not allow a proper voltage load to be carried through the car, so replace any corroded cables (don't even try to just clean them, it won't work). Check your grounds, grounding on these cars is important, though it not a common issue.

Let us know what your find.

 

The suppression module or noise filter is the 2 small wires that lead to a harness to the suppressor located nearby

The suppressor is actually a large cylindrical capacitor

The alternator needs a power source in order to generate power so there is a fuse

The problem with this fuse is that it is shared by other systems on the car , bonehead engineering

The fuse # 2 / 5 amp engine compartment fuse box and not the engine management fuse box is the fuse of interest

See page 37 as point 33 circle double hash and 34

http://www.jagrepair.com/images/Auto.../jagxj1998.pdf

The B+ post on the alternator must put out at least 13.5 volts in order for the light to no be present

The alternators are not very reliable new off the shelf

Recommend have them spin test it on their spin machine before installing

see page 51 to tied in circuits point 31 and 32 circle double hash

but then it may not fail until the voltage regulator heats up with load and time

 

First want to thank you for your time and help,This morning I put all my wiring diagrams,And starter , Want from the Battery forward,Check the grounds at the battery put on new ground cable ,check the battery output was 14.1 volts so next I want to the ground under the car from the transmission to the body replace it ,then replaced the cable from the alternator to the starter ,cleaning all ground ,check the fuse in the fuse box have voltage both side of the fuse ,but still have the battery light on and the car saying battery not charging ,I forgot to say this car has only 42k miles and has never seen rain or bad weather we keep it in our airport hanger ,very clean .my handy is 3348683580 if you wish to call again thank you for your help and time .ok

 

might have to let the alternator worm up a bit with a heavy electrical load until you get the charge light , while the light is still on then cheek the post on the alternator for the at least 13.5 output

the battery will not charge above 12.75 volts so no need to remove the post on the alternator to isolate the battery

during the course that you have the charge light do you actually have a draining battery or is it just a indication problem ?

You can put a digital meter on the glove compartment light socket and watch the meter as you test drive

 

I'll check it now, Again Thank you for your help.

 

if the charge light is on you will see the max fully charged battery voltage of 12.75 if it is an actual charging problem

the charging voltage sensor is inside the alternator in the replaceable voltage regulator

by nature of the cars wires connected you will see what the sensor sees at the glove compartment lamp socket

 

Check the voltage at alt,Only 3.4volt ,Check voltage at starter very low also ,But at the battery and the High power protection Module 13.8 voltage

 

I was out running errands

At 13.8 volts which is above the battery voltage of 12.75 shows the alternator was good at the time of the reading

on the alternator where you on the big wire B +

was the ground on the other wire of your meter a good ground while testing alternator?

 

Yes ,Ground was good ,In the Morning I'll reinstall The OEM Alternator ,I had it checked and it's good and remove the New Bosch ,Not a rebuild but New
.I'll see what it's show in the morning ,Again thank you for your time and help.mush appreciate.

 

Where did the Alternator come from ? My memory was the OE is Denso ... 210-0421.

There are a confusing number of alternators available in the marketplace. Be mindful ....refurbished and even rebuilt are terms tossed out that = very little. You want remanufactured -- and remanufactured by the OE maker.

The national chains sell things they call Bosch and Denso -- often using the term refurbished ..... Rebuilt. They may have started out as Bosch or Denso -- but they are not rebuilt by them. Junk -- they can and are commonly bad out of the box.

Not many years ago these were very expensive -- you can get the Denso very reasonably -- it will come in a Denso box and say Remanufactured.

Same with Bosch -- although you can sometimes get a new one from Bosch ... use the number on the unit.

 

You can go to a local reputable repair shop, not parts shop, and they should have an electrical shop which can rebuild the alternator relatively cheap. You should be able to look one up yourself, Montgomery should have someone. The mindset of doing the easy thing and go and buy one off the shelf isn't always the best solution, ...we all do it. I went through a couple alternators in a month for my Corvette before I rebuilt it myself 20 yrs ago and its still functioning properly today. I simply bought a voltage regulator from GM for $15 and returned the $120 one.

Make sure the amperage output is correct also or you'll get that Batt Light. You may have a 90 amp and need a 120 for example...I do not know what amp the XJ8 takes.

 

I'll tomorrow have my alternator check for output amp ,I still have the alternator I took off,that my autopart store . said was good ,But I want again thank you for your assistance on this .Have a great evening I'll let you know tomorrow .

 

If you have the OE off the car .... and you are sure it's the OE. Use that number.

I no longer have a good rebuilder around .. years ago we had many. If you do they are a good source .. although many times they can't compete with the manufacturers.

Examples: Nissan uses Hitachi for OE on some models. Almost impossible to get a quality rebuilt on the open market ... it's find the cheapest online dealer that sells the remanufactured. Many dealers sell only new for $700 and if the do sell the remanufactured it's around $450. Online dealer around $350.00

Valeo is OE for many MB's: Using the Valeo number you can often purchase a new (made in France) unit for not much more than remanufactured. Just search the number ... Bosch is the same way .... That's why I asked about who made the OE. I recently bought a Valeo for my old MB wagon -- Rockauto of all places .. I searched by Valeo number after I called Valeo corporate. You can do the same with Bosch. Not Denso ... the new are $$$

 

Wanted to thank you ,We have five jaguar ,And two Land Rover ,One Range Rover ,And I have a jaguar ,Land Rover Computer and they are no help ,Thanks for the messages and help

 

Find a local rebuilder and let them have a shot: they see hundreds a week.

After struggling to get mine off, ran it up to a local rebuilder for alternators and starters. Within minutes of returning home, a ten minutes drive, he call and said the car was ready.

 

alternator

 

Oil killed my first alternator, but my $35 junkyard replacement gave me problems when a washer on the power wire stud cracked and started arcing. Bought a new alternator, but the junkyard replacement was still good after fixing the stud/nut washer.