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There's a lot going on under that cowl!
The ignition switch looks like this separately:
and you can see it in situ here on the top right here, courtesy of member JoukoN:
The information in vern's link is the best I can see that shows where the ignition switch connector is in all that spaghetti:
It is 8-way and white, and there should be 5 wires running to it:
black
red/white
white/red
white/blue
orange
Here's hoping that it's the switch (glass half full): if cat & TG's hunches are correct, then a chafed wire is a possibility, particularly given that the steering column can be moved around.
BTW, the grass is always greener - I've been to Florida on more than one occasion and I'd swop your climate for ours any day...
That looks pretty clean compared to mine, where the multi-plugs have been removed and everything was spliced.
Here is what I would do...
1) Disconnect battery, if not already disconnected.
2) Find the wires leading out of the ignition switch.
3) Find the multi-plug where the wires end.
4) Open the multiplug.
5) Re-connect the battery.
Are the dash lights and other components still on?
If yes, you have a short to ground somewhere before the ignition switch.
If no, the problem is in the wires leading to the ignition switch or the ignition switch itself.
Please let us know...When it cools off...I would trade you weather...not ready for winter !
Last edited by Truck Graphics; 11-10-2017 at 10:19 AM.
This blue connector emanates from the ignition switch and terminates into the ignition switch cable. Portion of cable shows a red wire (can't tell the stripe) and a white wire with some stripe (again, can't tell the stripe). Guessing the red is R/W which should be the POS 1, and white could be the W/R or W/B (again, unsure).
Second photo, following, is from the electrical guide. It shows the wires emerging from each position of the ignition switch, and the logic of which are open/closed for each selection.
From electrical guide, wiring of ignition switch and wire colors.
My car appears to have a additional connector in the path (the blue connector). This is NOT in the electrical guide, and I can only assume there was a prior repair in this area. Since the 2 wires included the R/W (see photo), I disconnected the connector, reconnected the battery, and (unfortunately) the same result, with or without the key, and with the key in any position. I think this confirms what all of you have told me ... one strong possibility is the ignition switch has the short.
Truck Graphics was spot on. Disconnecting the blue connector (wires R/W and W/R or B) has no effect on the issue, so what's remains is the ignition switch.
Now I'm still struggling on how to remove the ignition switch, so I can bench test for appropriate continuity per the electrical guide.
I wish any one of you were here. This morning it is only 75F, overcast, and quite pleasant to work on the car.
Vern of Nevada provided the link for downloading the JTIS Guide. I am reviewing section 211-04 for guidance now.
BTW, unrelated, wife went to beach yesterday. While wading in Gulf of Mexico she lost her iPhone. See what you're missing here?
Disconnected the white multi-plug. Now there are NO WIRES wires emanating from the ignition switch area to anything; just hanging loose. Connected battery. Same result. Clearly the failure of short to ground is in the ignition switch.
I hate it when the prior owner(s) modified the car in such an unorthodox and undocumented way. There is no 4-pin connector (any color) from the ignition switch cable path, as shown in photo from MichaelH. The wires from the ignition switch (in a wrapped cable bundle, go directly to the white multi-pin connector, save for two wires that are routed through a blue connector patch. Also, I can't find any screws securing the ignition switch in place. Nothing looks like the JTIS picture. I do not know how it is mounted so securely. There is a plastic tie, but that is it. There are two screws nearby on what appears to be the steering column mount. See (photo). Are these the ones I am looking for?
Viewed from underneath, looking up. These torx screws are only ones I can find. I think all other potential screw locations are just threaded holes, with no screws.
I need to get this ignition switch out and on the bench. Short of a blue torch, any suggestions or requests?
Still frustrated in Florida (but weather better today), Bob G
Hello all. Third update. I just realized that my logic might be totally backwards. All of you clear thinking, younger men can chirp in on this.
I have ALL wiring from the ignition switch to the white multi-plug disconnected, and still have the fault, with or without the key inserted at any position. Now I'm thinking the issue is NOT the ignition switch, but further down the wiring chain. Please comment.
Hello MichaelH. Fault continues with all connectors/wires from ignition switch UN-plugged. So, fault (short to ground) exists in one of the many paths emanating from there. I see in your earlier post that there are a large number of possible paths.
Would removing fuses to kill power to each of these possibilities appropriate for isolating? If not, how best to proceed?
If you still have a fault with all of the wires disconnected, then you DO NOT have a problem in the ignition switch. Apologies for Internet yelling. Just wanted to be clear. This pertains to the three wires leaving the ignition switch. I can't account for the blue plug. Will put on my thinking cap (as people born before 1960 used to say) and try to come up with a "short cut" to help isolate the problem.
Last edited by Truck Graphics; 11-10-2017 at 02:35 PM.
...So, the car still won't crank? ....What is the single try provision of which you spoke earlier?....I know this is frustrating, but on the other hand, you can look at it as if you were solving a mystery. Somewhat satisfying when you find the bad guy causing the problem.
At least I learned something today. This would not have been possible without the fine help from all of you.
OK. No wires from ignition switch are connected to anything. Fault still exists (same) when battery power connected.
Chasing down all the Ignition 1 accessory position linkages, I find distributed GROUND sent to 20.1 cigar lighter, 10.2 internal dimmer lights (disconnected), 13.2 door lock module, 13.3 BPM, 07.1 A/C, and 21.1 CAN Network.
Also, when Ignition switch working, apparently Position 2 also engages all position 1 items (see diagram in my recent post today). So, that adds a bunch of other items, like engine management, gear shift, auto-lock, suspension, and so on.
As I have shown in my earlier replies, I do not know what I'm doing. Does removing fuses for these items disable the ground?
What a puzzle. I wish I knew which was the missing piece.
Bob,
I suspect that the blue connector in your picture is the key exciter ring connector. The two black wires on one half correspond with diagram 13.2 (this and 13.3 are missing from JTIS), so most likely not a PO's modification.
OK, if the symptoms are still present, then there's a short on the wiring somewhere. Now here's the rub: a short on any of the wires will pull down the entire 'web' so you have to identify which one is the culprit. One thing I'm not clear about: you mention earlier that all the dash lights come on when the battery is connected. I associate that with the ignition ii (on) position rather than ignition i (aux). Please can you confirm.
Either way, then you need to trace the corresponding wire from the other half of ignition switch connector. Each of these goes to a splice: the white/blue wire to FCS26, the white/red to FCS20. These splices are somewhere in the fascia area. I'm sorry I can't better describe the location, or what form the splices will take, but each will be a point where 7 or 8 wires of the same colour code join together.
Hello MichaelH of the Jersey, Channel Islands, and others following;
Thank you for the words of encouragement. I appreciate the explanation of the black wires into, R/W and (wires R/W and W/R or B) out, part of the ignition chip sensing ring. I had no idea. Anyway, thanks to all confirming the the ignition switch, now completed isolated by unplugging the white connector, is not part of the problem.
Now to confirm, are the FCS-x splice locations normally floating or +12V -- if so, when I find them, and I will, I can use the ohm meter for testing float, or the voltmeter for testing +12V (with the battery connected) --- right?
At least the weather is now cooperating. Anyone visiting Florida is welcome to stay at my place, 40 miles south of Tampa - in exchange for your fine help.
Mmm. I'm wondering if the 'no crank' is significant here. A short to ground on 'aux' or 'on' is only what the ignition switch does normally as part of its job and shouldn't stop the car starting. BPM issue?
Anyway, with the ignition off, I'd expect 12V on both white/red and white/blue wires with the battery connected. Unlikely, but not impossible, that there's a short on both circuits, so check for 12V on those first and report back.
I have researched the FCS20 and ..26 in the electrical guide. Here is my understanding.
FC stands for the fascia area, just as you said.
The S stands for splice, any location where two or more wires connect.
20 is driven, when connected, by ignition switch position 1 (accessory).
26 is driven, when connected, by ignition switch position 2 (on).
Wires (?) WU (white/blue) from FCS26 go to passenger side fascia fuse box, where the switched ground completes circuits for many fuses.
Cannot find FCS20 (accessory) anywhere in electrical guide except on figure 02.1 Page 45, which shows WR distributed to seven other items, just like MichaelH said.
FC26 also shows in following figure as the connector for the major instrument pack.
Major Instrument Pack, shows connector FC26
A lot of research points to the BPM.Something in the ground distribution is pulling down the wiring to ground, not including the ignition switch. So, as usual showing my ignorance, where is BPM located? I would like to disconnect it and see what happens when power is applied.
Hi Bob,
Be careful not to confuse FCSxx and FCxx as they're different beasts, otherwise you have got your head around things.
I was thinking of the BPM as it connects to both circuits and could be the root of a 'no crank' - although at this stage it's only a hunch - but I'd still do the 12V checks before digging any deeper. They may make subsequent checks easier. I'd also avoid powering up with a module disconnected.
I have a clue ! Earlier on MichaelH said there were five wires that go to the eight hole white multi-lock (FC4). On my Jaguar, everything hangs loose, courtesy of the previous owner, so I only knew of three wires - positions I, II and III on the key.
The black wire is ground (FC4-5). Don't think that's important because we are looking for an unintentional ground.
Ah...the fifth wire, Dr. Watson. What does that do? The fifth wire tells the Body Processor Module whether or not the key is in the ignition. If the car thinks the key is still in the ignition, it won't turn off the dash lights (I don't think...I'm not sure if I'm a great detective or just foolish).
Anyway, this wire is, in my 1999 wiring manual, identified as Blue-Red. There was that blue connector and blue wire you found. If you connect the three wires leading from your ignition switch but leave the blue connector unattached, you may find the problem doesn't go away. This will narrow your search to the blue-red (may be other color in your car) wire.
Now...here I am thinking aloud...this wire does not go to ground. It goes to the BPM. If it is grounded, your car should work properly....Perhaps you should try grounding it and see if your problem is solved. I would use a wire tap before the connector because these are the two areas of concern. If the key works properly then, your problem is either in the ignition switch or the connector. Hopefully the connector.
Re: the BPM...I would avoid exposing this for now. In my recent experience, it is difficult to reach (behind the glove box) and is apparently fairly robust. I would expect to see some sort of code thrown if it were malfunctioning. I say this because I replaced mine, and it didn't make a hill of beans difference in solving my problem. One of my Jaguar manuals also says so much, but I didn't listen. You are more likely to find a short.
Last edited by Truck Graphics; 11-10-2017 at 06:49 PM.
11-09-2017, 04:33 PM
