Can anyone tell me the hookup for a remote starter for under the bonnet? 1988 XJ40 VDP, 542735 I saw info for it, but wasn’t able to find the white wire at the rear of the engine going to the starter. It’s difficult for me to get under the car to hook directly on the starter.
I could not own a Jaguar w/o your generous help.
Cheers
Joebob
Joe,
Not sure what you are trying to do. Do you simply want to put battery voltage directly on to the starter solenoid via the White wire? If so, why not do it through the starter relay (white base on component panel under passenger side dash)?
If you remove that relay and jump pin 30 (Brown wire) to pin 87 (White wire) in the relay base, that will put battery voltage direct on to the starter motor solenoid terminal to engage the solenoid which in turn will put battery voltage on to the starter motor via the Brown wire from the battery positive terminal post.
Hi Joe,the white wire can be accessed from above, it is situated on the solenoid that throws the pinion into mesh and makes the contact for the starter to be energised. I’m afraid you will have to do it more by feel than sight.
Something was said before bout this hookup being only able to spin the starter. Imagine what a nightmare that would be if trouble shooting starting probs, & the starter wouldn’t start the engine
. Talk about going on a wild goose chase! Which is true? Gets confustng.
Bryan;
Will ths method (pin 30 to 87) also start the car if the key is on? I would prefer to make the hook up under the bonnet, & maybe leave it there permanently.
Robert,
If the ignition is ON, when you jump the starter relay pins 30 & 87 the engine will crank and, all other things being equal, it will start. If you leave those pins permanently jumped, the starter will continue to rotate until something burns out or you flatten the battery. That circuit is not fused.
Just what are you trying to achieve with this project?
Bryan;
What I wanna do is have a convient way of cranking / starting motor instead of needing a helper or jumping inside all the time. Being as you’re under bonnet almost as much as driving, it’s a good idea, especially since I’m disabled & a little slow. I would hook up a simple button switch on a short wire so I could work either side of car. I know better than to leave jumper permanantly attached.
Robert,
Well in that case, my suggestion to jump pins 30 and 87 in the starter relay base once the relay is removed ain’t gonna work. The starter relay is in the cabin under the passenger side dash on the ‘component panel’ as I told you in my original reply.
Bryan;
I don’t understand what you’e saying, now you say it wont work, jumping 31 &87? I would then rout it out thru the firewall into the engine bay to a hand held momentary on button switch. I would splice thiese into 31 & 87 to preserve circuity in the circuit
Joebob
Robert,
Slight misunderstanding. Jumping pin 30 and 87 in the starter relay base after removal of the relay will not allow you to crank the engine remotely within the engine bay. That is not the same as splicing wires to the brown (pin 30) and white (pin 87) wires under the relay base with the relay still in place and leading them through the firewall to a switch with which to activate the starter from within the engine bay.
Out of interest, why would you want to do that? In the absence of a willing helper, I can only think of two applications of that technique - checking the cylinder compression pressures or checking for a spark from the HT leads whilst cranking a dead engine. Either of those activities are surely so infrequent that hard wiring in a remote starter switch seems a little OTT. 
Bryan; The reason I want to do that is, I don’t need helper, & now w/ my no start prob, w/ my luck, I will be a long time under the bonnet. All older Jags should be recalled to install one
Robert,
If it is essential that you get a method of remotely cranking a dead engine yourself whilst working under the bonnet perhaps you could make up a switch lead similar to the one I made to activate the fuel pump remotely by jumping the 30/87 pins in the fuel pump relay base. I fashioned a jump lead with spade terminals which fitted in to the relay base pins 30 and 87 with a spring-loaded toggle switch (of the type used in olden days for a screenwasher ) on the end. You could make the lead long enough to reach from under the passenger side dash where the starter relay resides to take it out of an open front window from that relay base to wherever you want to operate the switch around the area you are working.
On the rare occasions you would need to use it, it would not make sense to hard wire it in to the car via the firewall.
Many thanks for the ideas, Bryan. It’s confusing which one is the starter
relay, some books show it 3rd from the left, & some the 4th in the row of
relays under dash on pass. side. (LHD) One also says its yellow, & i have
one that is. I hope I can go by the colors. Will also look at crank sensor.
Will have a look tommorrow.
I appreciate all
your help.
JoebobRobert there should be a legend on the knee pad that indicate which relay does what. Like Bryan I am a little confused as to why you need to be able to crank the engine while out of the car, can you describe what you are trying to correct? Is it no start and if so what is the history?
I had a period of no start which ended up being the ignition amplifier. I had discounted this as the fault as I had tried a known good one, what I did not realise at the time was that it needed to be grounded, once it had a good ground the car fired up.
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Thanks, Robin;
I want the remote cuz it’s so much easier than jumping in & out of the car for some procedures. I thought everyone had one. I always did.
Robert,
As I mentioned previously, the factory circuit diagrams for an '88 model show the starter relay base to be WHITE (the base, not the relay can itself of course).
Another clue is that the wiring at the base of that relay comprises two Brown wires, one White/purple wire and one White wire.
I suppose a simple way to check if you are looking at the correct relay is to pull the one you think belongs to the starter and then try to crank the engine using the key. If it doesn’t spin the starter, you’ve found the correct relay.
I would think a simple parallel circuit on the ignition wiring to a flyback stop/start switch in the engine bay would work. Maybe!!!