Heh guys

Just noticed the red lightning bolt symbol coming up on my dash

When I look at my charge gauge it seems to be in the high charge region when the light comes. I would sit at the traffic lights and it would disappear...as soon as I take off, the charge goes up near the red region (but not on it) and the light comes on.

I was running the A/C but as soon as i noticed it i turned it off....no change to the light coming on.

Firstly, what is the lights exact purpose? Alternator charge too high/too low?

Is this telling me my alternator is perhaps not putting out within the set point voltage? (ie. alternator is on the brink?)

I thought also a possible issue with my battery (alternator can't charge it) but my battery light is NOT on and the batteries' hydrometer (built in) is still green.

Anyway I typed all the above and went and did some checks myself...


Battery voltage across battery terminals when off = 12.73Vdc
Battery voltage across battery terminals when just turned on = 12.9Vdc
After about 10 secs and steady (idle) = 13.4Vdc

When the wife puts the foot on the throttle = 14.2Vdc
Then back to 13.4Vdc idle.

This to me tells me the alternator is doing its job right?

I know checking voltage potential is not really a good means of testing a battery but she has the little green light still lit....I think it's ok (no battery tester around)

What do you guys reckon? Something sinister at play ?

Thanks in advance my friends...

 

Id expect the light to behave the otherway around if it was volts related and the way you see if it current related

Do the simple thing first

Check -
battery levels for each cell
Specific gravity
load test (measure the volt drop while starting the engine)

Try giving it a run with the battery from your 4x4 and see if its the same

Id eliminate the battery before looking at the alternato
If you do need a new alternator replace it with the highest current one you can get. I'd guess yours is around 60-80Amp and a 110-120A replacement will be easy to find these days


Cheers
34by151

 

Paul,

IT NEEDS A LEAPER, and you knew that was coming, duh.

That "Green" thingy in the battery is ONLY for the cell it is dipped in, NOT the whole battery. Bit of a sales gimmick, sadly.

Those readings you took do indicate all is OK, on the surface. I would do it one more time, this time LOAD that alternator up, and have Wendy hold it on about 1500rpm, then ON the headlights, let it settle, then add the A/C, let it settle, ALL the time maintaining that 1500RPM as best she can, it is not an exact RPM, just a good steady fast idle.

It that comes up to snuff, I reckon the Alt is good to go. A proper load test by a "sparky" will be the next suggestion.

Time for drinks.

Put another battery in it, from whatever you can beg/borrow/steal one from, and do the same. My reasoning is that the battery "could" be internally having a female moment, and causing grief.

I will keep thinking.

 

I think Grant is 100% right here, no leaper = unhappy cat. That's about all the help I can be.

 

Guys thanks for the feedback. I new I could count on you all!

Well James and I are thinking maybe as something a simple as battery but not sure. (hopefully)

Tomorrow we are gonna swap in a known working battery (if the Mrs leaves her car unattended) and see if we get the same fault.

Gonna do the above mentioned load test as well...seems like a good idea.

Yeah I never fully trusted those little indication lights on the maintenance free batteries.....now you have convinced me.

True Story: This only started happening today after I pulled out across the road from a Jaguar dealership (window shopping)....i think the ole girl got jealous and started getting cranky with me lol!


Will update progress after tomorrow....cheers

 

MAAAAAAAATE, give her the credit card and tell her there is a sale on somewhere, and she is GONE.

A cash note for a cab, coz traffic will be a killer with that HUGE sale, also helps if vandalising her car is a required pastime.

 

Leaper removed....its amazing what a bit of a polish can do to make it look more realistic...

 

HA, those ears would be a scream at 100KPH, fair dinkum.

 

Day off tomorrow but lots on including making sure my own Jag drama is sorted.
Would have been a good chance to catch up with you two.

 

Bummer dude. The offer is there if you change your mind. Gonna slip down to Caloundra and see the new Jaguar Cx75 in SPECTRE also.

 

Oddly enough, I think I have a battery hydrometer in my odd lot tool place.


Way back when I worked in a full service station, we used a hydrometer regularly.


And, I have an ancient volt meter. the one with two spikes to read old tar
covered batteries, cell by cell. Almost all 6v's in that day...


I am still proud of my patch cord for my VOM. Plugs into the cigar lighter.
Read volts in real time under various load and rpm conditions.


Made from left over odds and ends. Add soldering and shrink tubing.
Looks like a pro tool.


And, yeah, I have a dwell meter.... I've not used it ion decades...


Carl

 

This guy stole my leaper

Cheers
34by151

 

Well the plot thickens...

With a new battery swapped in she still throws up the same fault.

The Lightning Bolt symbol....that means Alternator is giving a high voltage right? Is that the purpose of this indication light?

If thats the case then maybe it is correct...as measuring the battery terminals at about 1500RPM she is charging at 14.2Vdc. That seems pretty high I would think. I am thinking that the light is actually doing its job.

Worse case scenario It could be the alternator but I want to cross everything else off the list before I got to the trouble of swapping her out...

What else do you think could also cause such a condition? Any clues?

I'm trying to find out in my workshop manual what drives that little light on but so far can't find much...or even a description of what the light means....might have to download an owners manual..

 

Hi Bro

Check this out, it sounds like you have a faulty Regulator

What Causes an Alternator to Overcharge? | eHow

 

Paul,

That 14.2 directly after an engine start is deemed acceptable, and mostly settles to around 13.8 after approx 15 minutes or so.

I have no idea hat drives that lamp either, but I will sip some Necta and go looking.

Back soon I hope.

 

Quicker than I thought.

"Lightning Bolt" light is the Alternator lamp. Designed to come on when the Ignition is switched ON, and the Alternator has a diode issue.

A Diode issue can still produce the 13.6 - 14.4 at the battery, so that voltage reading could be a diagnostic blunder somewhat.

"Miniature Battery" lamp is the overcharge lamp. It is designed to come on at "about" 15.6V, and indicates the regulator has failed.

Sounds like an alternator diode has dropped out. Choices now, repair that 75amp unit, or update to the 110amp Bosch unit.

Here ya go.

V12 Alternator Upgrade.doc

I got mine from Lucky Phil @ H & H Prestige in Melbourne. Make sure he supplies the 10mm LONG mounting bolt with the unit.

 

Heh guys

Thanks to all for the help so far...

I'm on the hunt.. and I'm getting closer to at least understanding the system a little better. The ROM(Repair Operations Manual) calls the thunder bolt light 44: Ignition Warning Lamp

That doesn't help much but...if you look at the schematic you can see a component 302: Overvoltage CU which connects to lamp 44 with a resistor in parallel across it.

The W/LT pin from component 302 goes to lamp 321: Overvoltage W/L

Looks like we are in the right area as those lamp numbers match up to where they appear on the dash. 321 is where my symbol of a battery is and 44 is my lightning bolt symbol.

Mmmm....but what is component 302? What is the CU and W/L suppose to denote? (CU for coil W/L for warning lamp maybe?)If I can find out if and why 302 is bringing on lamp 44 it might lead me in the right direction...

Any clues?

 

And this is why you are known as the Wizard of Oz...

Cheers for that mate. Looks like the nail is about hit on the head.

James too thought similar but we both wanted to be doubly sure before I ripped her out.

Mate I read that write up you did. Cheers for that. I love they way you type it up lol! In my language ha ha ha

I can test the diodes no problems when I take it out of situ however its probably a good time to upgrade to the higher current version I suppose.

These things always happen when I am due back to work (this Thursday) looks like it will be a December/January project now!

 

Alternator will NOT fit out thru teh bottom.

1) Air cleaner assembly off.
2) Top hose off.
3) RH thermo housing off.

Now the memory is buggered, does Goose still have the air pump fitted????, I simply do not remember.

4) Remove air pump, and its metal mounting bracket.
5) Under the front, slacken, then undo and remove the alternator adjuster threaded bolt.
6) Undo the alternator pivot bolt nut.
7) Remove the wires from the alternator. You did disconnect the battery did you not?.
8) Grab hold of the alternator, and shake it around as you slide that pivot bolt out.
9) Lift/juggle it out thru the top.

As I said SIMPLE. Should take no more than 30 minutes. You got E Fans, so heaps of extra room.

 

Cheers Grant...you truly are a wealth of knowledge

Mate I have a few questions for you :

1) Firstly, are my labels correct in the picture below?
2) If I take off the RH Thermo assembly, will I have to re bleed the coolant system and all again when finished as well as a top up?
3) Is that air pump connected still? What exactly is it or was it used for? Assist to push out exhaust as part of emissions system?
4) Looks like my alternator has had some sort of upgrade. I can see a red (10mm/7AWG?) wire coming up from there, along the RH side and across to bolt onto a lug on the fire wall. Wiring upgraded from stock perhaps? The Goose is 75Amp Alternator yes?

Mate cheers again for all your help...you say much drinking is required to work on these ole girls....is Scotch the correct coolant to use?