Going on a club run this AM but I can send you a pic and description of my 86 later today.

 

Over the years there may well have been a few subtle variations in starter relay wiring. The '1987 and earlier' diagram I have shows....

W2 white/yellow and white/blue
C2 solid brown
W1 white/black
C1 white/red and white/red (one larger gauge then the other as I recall)
C4 white/blue not used

However, I'm sure there were other variations on the 1987 and earlier cars.

The solid red wire seems odd. I agree with Grant....I'd disconnect it. Does it look like someobody added it in, or does it look "factory"

Cheers
DD

 

Hey Grant,Welcome back to the Twilight Zone..
This,car starts when it wants to.Odd enough.
If that big red wire isnt hooked to any power source,the starter wont work.
I think it goes to one side of solenoid of starter.And one schematic shows it going to one of the battery post on bulkhead,(firewall).
Whats odd my book shows to different ways the wires go on st relay.
One shows wht/yel on,W2 going to ign switch,and wht/blk on W1 going to feed back minitor relay.
The other shematic,shows wires on st relay as follows: W2 has wht/yel. W1 blk/grn,going through start inhibitor switch,to ground.No feed back monitor relay,and no Blue/Wht wires,(C4) on either shematic'
very confusing.
Im afraid ti drive car anywhere and park it.It may not start again.

 

Hey Doug,Its hard to tell if its factory.Its about a 12 gauge wire,and it runs down into a soft rubber type shieth or tube.then to starter solenoid.If I connect it to 12v starter turns.
Regarding st relay.Mine is as follows: w2 wht/yel,wht/blk.W1 blk/grn,C1 two red/white wires,one bigger gauge.and that solid red wire.C2 big brown wire.C4 two Wht/Blue wires.I dont know what the white blue wires are for?

 

Hey JT,that would be great!
Thanks.

 

My 86 NA.

C1. W/R. w/r
C4. w/blu
C2. BRN
W1. w/blk
W2. w/grn. w/y

 

Ok,that sheds some light.
Only difference in mine is now w/grn mines blk/grn and my wht/blk and wht/yel are hooked together.on w1.
and of cource that red wire to starter

 

My old starter relay would just let the starter click when it got hot and take multiple attempts of the key to finally fire up, I opened it and cleaned it and it worked good for a little while then back to its old tricks. I put the current one on and it was good for a couple years now it acts up when hot too....not a fan of these relays at all. Wish I could get a square answer on an upgrade and how to hook MY wires up to it....the jaguar specialties site is on crack if they think those wires are all there is on a 76 to 89 XJs.

 

Hhhmmmm, just read an old thread where Grant suggests finding the red/white " joiner" spade and cleaning it.....could be on to something.

 

well,from what I traced.The two white/red wires from st relay,one goes to ecu # 26.The other,white/red spiral,goes to a three way connector,on rht front inner fender by injector multi plug connector.It is not connected to anything.the other wires with the wht/red spiral wire.are wht/purple,wht/green.
I believe someone substituted the wht/red spiral,with the solid red wire.
I think that three way connectororiginally went to cruise controll unit.( someone removed from my car)and solenoid on starter.
Possibly.

 

Ok there,are total of three relays on the rht top rear inber fender,start relay,and two other relays they look like fuel ralay same size.there are two wht/red wires going ito one of the relays,my book shows one as a posaable cold start relay.

 

Everything is hooked up correctly,and as im cranking eng I noticed power resister getting very hot.
Is that nornal?

 

OK, since I am not clever enough to loop all those threads together, so here goes.

Its 10.30 AM, and the JD is FRESH.

By now you know the absolute excellence of British Engineering and Theory you are dealing with.

That second "small" relay in that cluster with the starter relay is in fact the Cold Start Relay, and since the Poms were soooooo undecided on these cold start injectors, they simply left all the stuff intact, so reconnection in the next MY was simple, even for them.

The other relay, NO idea, but the USA cars did get a lot emission related stuff we only dreamt of HAHA.

That Red/white wire is ONLY active in the crank mode, no matter where it goes to. It is DEAD at ALL other times, or should be.

That RED wire is possibly a by-pass for a BAD Red/White factory wire, and that may be at that infamous spade joiner I constantly talk about. To find that joiner you will need to think RHD, and we have the brake booster on the RH side, and that White/Red wire passes around the booster, and at about 4" inwards of that booster it travels down the firewall towards the starter solenoid. At about the Transmission dipstick level is a WHITE (maybe BLACK now) rubber cover, THATS THE JOINER, and it causes many a V12 starter to be diagnosed as DEAD. I have actually disturbed that "joiner" by checking the ATF level, coz things are so crammed in that area.

Why you have that White/Red wire anywhere else is a mystery to me, coz, as I said, it is ONLY alive in the CRANK mode.

If that resistor pack is getting HOT, you got a short (maybe many) somewhere.

When I rewired my engine bay a long time ago, I found a lot of wires (mainly on the RH side) that went down towards the front, joined to others travelling in the same bunch, and went back to the rear area, why,???, no idea, so I did the joining at the rear section, and had about 7metres of wire left over, and a neater set up, and less wires travelling just for that sake of travelling.

I am going to the V12 in the storage facility sometime today, and I will unplug the coil and crank it, and see if that resistor pack gets warm/hot. I doubt it, but will post back later tonight Aussie (real world) time.

 

My 86 only has the starter relay and one other Bosch relay under the cover.

 

I believe your right about a bypass of that wht/red wire.Eng turns over fine when its hooked to the C1term of st relay..,its just back to not starting again..My luck..
I havent seen any cold start injs,they where not in the inj loom anyways.
Is it possable that other relay may be the feed back moniter relay? One has a J on it.I dont know if that means anything.There are two wht/red wires going to it,a solid white,a blk/grn a solid blk..wht/blk.
And thanks for going to check the Power Resister.

 

Why do I always get the odd ball car?
I dont know what the extra relay is or what any of them are..
I can only note what wures go to each one,Ill note it and be right back.
Ok,heres what I have: Relay to right of st relay,Has a big J on top of relay.term 87 wht/purple, term 85 Wht/Grn, term 86 (2) Wht/Red spiral, term 30 brn/wht
next relay: term 87 wht/blk,term 85 (2) blk/grn, term 86 wht, term 30, (2) blk.
Maybe someone can identify them..

 

Ok,one is the fed back monitor,other is cold start relay.Even though I dont have any.Cold start injectors.

 

OK, I'm back.

The beast in storage (85 XJ-S V12), had the inertia switch and HT lead pulled for the test.

Spouse cranked the thing, I held the resistor pack, NO temp change felt.

Refitted the HT lead, and reset the switch, and fired the beast, and ran it for 20 minutes. NO temp change in the resistor pack felt. Albeit the engine bay was getting warm (outside temp 10c) but that pack was NOT noticeably any hotter than anything else in the area.

Shut it down.

Unplugged the EFI loom at the compressor connector area. Ign ON, replugged, and NO activity of the injectors at all.

I did not take any DVM's with me, so readings of various wires is simply not there. It is NOT my car, just one of 21 in a private fleet I maintain, so I do have to be careful.

 

Further to Grant's points, it seems increasingly likely that you have a loom problem. It occurs to me it might well be that it is in the loom that runs past the starter relay cover and goes to the power resistor and the associated bits. This bit of loom might have been disturbed sufficiently when you changed or fiddled with the relay contacts to STOP shorting, and now it has started again.

It would be a fiddle, but basically low-cost, to unwrap that part of the loom from where it emerges from the wing (or even remove the inner wheel arch at the back of the front wheel well and go into the bundle there) and splice into it and and redo it up to the power resistor and anywhere else that it goes to.

It is clear your car will run, but just (just!) a matter of running down this electrical fault.

Greg

 

Greg, my shout, AGAIN.

I never thought of that bulkhead connector in behind that panel. ALL the wires from the engine bay go thru that 2 rubber connector arrangement, and the best part, it is made by LUCAS. The exception is that shielded wire, that goes thru its own grommet, NOT made by Lucas.

Age is now telling in there, and the fact you have found odd connectors inside the car near that arrangement has always had me intrigued as to WHY.

Best of all, YOU ARE NOT ALONE here. I have had to go right back to that connector on 2 that I have rewired from engine bay fires in the past, BUT, they were both PreHE, so many, many, many more wires in there, and the age is way more.

The issue you got, is you are looking for that damn needle in a huge haystack, and I really dont envy you that task. It really is ONE wire at a time, and is not finished until ALL wires are done, no matter what you think you may find on the journey.