As stated above my “new to me” beautiful 62 was converted to negative ground. I don’t know when or by whom. Right now “nuthin” works. I’m fine with electric work on a car but this is a little intimidating. Is there a conversion kit or some kind of document? I would have been fine with it remaining a positive ground but this is the car I have, warts and all she my baby now. The woman I purchased her from painted her rattle can scary green! She’s all there though.62 years in Southern California so very rust free!

The picture I received

The best view of her

Reality. The bumper guard is removed so I can get in front of the car with the garage door closed.

 

The change to positive earth shouldn't have made much difference to the car as most items work correctly on either polarity, I think the main items that can have issues are the ammeter and possibly the fuel pump if its been replaced for a later one. Things like the heater fan, wipers, lights etc. should all work fine.

The best place to start is to look at whether any modifications have been made to the loom and then start tracing through the power feeds to check that you have power at the fuse box (there are only two fuses on the MK2 originally and these are located on the inner wing under a metal cover).

Just to add that personally I love the colour.

 

As Homer states very little needs swapping over apart from the Radio, Ammeter, clock and Battery. Everything else should work regardless of the polarity but there are some things that are polarity sensitive and might need swapping such as the fuel pump if it is an older SU pump.
The question is have they converted the car from the old Dynamo to an alternator? If a new alternator has been fitted then the RB340 voltage regulator would have been removed as alternators have a built in regulator. If this is the case I can post a write up on the wiring in the RB340 which is required and that which is not. I converted my S Type to Neg earth several years ago and still have the write up I posted on the S Type forum. S Type has more fuses but the conversion is the same.

 

i've found that, in general, solid state devices are most likely to be polarity sensitive. as many of them were originally designed without multiple polarity considerations. ...now they are.

 

contact Star Electric in Monrovia: https://starautoelectric.com/instruc...ing-generator/

 

Agree with everyone above. If the car's converted to negative ground, I'd keep it like that as long-term it's more convenient. Has the dynamo been replaced by an alternator or was it repolarized? Since you're recommissioning, you'll most likely replace the fuel pump anyway. The clock has problems with a polarity change, but almost certainly needs work and can be left or disconnected for now. The best thing to do with the ammeter is replace it with a voltmeter, especially if there's an alternator.

We had a discussion on all this stuff not so long ago. If the forum had a decent search engine (gentle hint to whoever takes care of those things) (and if we didn't ramble off topic), it would be possible to find and link to it.
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to make the Clock work again, send it to Mike at:
www.jaguarclock.com

he does a (reversible) fix for $85. USD and you can hear it ticking again.

 

She still has the generator with the power steering pump attached. The fuel pump mast have been replaced because it works and so does the amp meter. The wipers move but just barley. Probably a different issue though. That’s all the works besides a few exterior lights.

 

Sounds like the symptoms of sitting for a long time. The grease gets congealed in the wipers, the motor will need to come out, as likely will the wheelboxes and the cable and get cleaned and regreased.

 

The thing to do is get a wiring diagram for the car and then start to go through it and find out where the issues are, as it sounds like a lot of stuff is out I would work my way out from the solenoid and check basic things like the connections to the ammeter in the dash and the fuses first.

The image below might help.
One other thing, if you do remove the wiper motor to clean the grease out of it and get the rack out make sure that either the wire colours can still be seen or mark up the wires on the motor and the loom, the wires tend to lose their colour in the engine bay and maching them, back up afterwards is a pain because there are about six wires to the motor (its a fascinating electrical design but over complicated in my view).

 

or something as simple as the wiper motor Brushes worn out.

 

Because the colours fade out on the wiring I put a small piece of masking tape a round each end of each wire and numbered them so when it came to reassemble I just matched the numbers up on the ends of each wire. Simples.

One important thing to check if the car has been sat for a long time is the earths which might be causing the majority of your problems. A slow wiper motor could be a poor earth. In the wiring loom there are black block bullet connectors that can be single, double or even quadruple earths all coming together. These tend to corrode and are a simple fix. Pull them apart clean up the connectors and then put some copper grease on the bullets before pushing them back in. Martin Robey sell new ones and they are about .30 pence each. Also check the earths going to the body of the car as a touch of rust under the bolt or washer can cause a bad earth.

 

I used masking tape even with new harnesses throughout. It's easy to foul things up in a number of areas. e.g. the cluster of wiring around the wiper motor on an S Type.

 

Just throwing this out there- I got an assorted kit of the bullet connectors from www.thebonnevilleshop.com. These connectors were also used on british motorcycles which is their focus. They are in the US, so freight May be less. No connection, just saying.

 

I have an original maintenance manual for my car. The wiring diagram is for the positive ground. Does anyone know where to obtain an updated wiring diagram with the negative ground setup?

 

The color is nice in this picture but that was a few years ago. Now it’s faded and uneven. It was painted with a rattle can so in real life it’s a bad job. I’d like to figure out the original color and give her a proper repaint. Right now I’ll never lose it in a parking lot!

 

Oh the wiring, connectors and grounds are all falling apart. The deeper I get the more I see to be done. The best part about this car is that everything is there,manuals, tool kit and 5 wire wheels and the incredible lack of rust! Everything else is worn the @#$& out!

 

There isn't a negative ground diagram as the cars weren't originally manufactured negative ground. The way the diagrams are made, there's not much to change apart from the polarity of the battery.

It's possible to do a good job with a rattle can. A friend of mine used one on the door of his R-R and subsequently won best car in the region.

 

Just change the symbols at the battery like I did in my screen shot; now you have a diagram for "NEGATIVE" ground.

 

all that needs to be done is to re-polarize the RB340 Voltage Regulator assuming the car still has the original GENERATOR.
Takes less than 3 minutes.