FrankieB

I've been having a problem with the orange GEN light staying on while the engine is running, and while investigating the issue I managed to fry the red wire going to the warning light relay.

A schoolboy mistake on my behalf, as I had taken the wires from the protective connector to clean the contact surfaces up and it touched the relay bracket, resulting in a big puff of smoke and the red wire melted right back into the wiring loom.

I believe that it goes to the voltage regulator on the fire wall as I tested the continuity during my tests.

My question is can I simply replace this red wire between the voltage regulator and the WLR, or does it connect to anything else within the wiring harness.

Many thanks,

Frank.

oldcutlass

The warning light is a function within the VR through the brown wire at connector pin 4. I don't have a schematic for your car, I would cut the tape off the wire bundle all the way to the firewall and make sure none of the other wires were damaged. If you see any damage replace those wires and check the harness inside the car including behind the fuse panel.

FrankieB

Many thanks for the swift response oldcutlass.

I've stripped back the tape to the firewall and the red wire is burnt back to the splice with all the other red wires, but it's only about six inches long and I can see no further damage to any other wires. I should be able to solder a fresh piece in place of the damaged one in the original position.

As for the warning light relay, it would appear mine is a 63/64 only part from what I can gather reading through the various threads on here. There is no brown wire attached to the voltage regulator.

The wires from my VR are, Light Blue = F, Green = 2, Red = 3 and a condenser on terminal 4.

The wires on my WLR are - Red (the one I burnt), Brown to the warning light and Purple from the alternator.

It looks like the relay is toast going by the tests I've done. There's a NOS one for sale on ebay but it's $125 + postage, import duty etc, so probably $200+ by the time it gets to me in the UK.

I can't justify spending that much to be honest, so will look for an alternative or maybe even upgrade the alternator to an internally regulated model which would supply the feed to the warning light without going through a relay.

Anyway thanks again and I'll crack on with the wiring repair and address that problem at a later date.

Cheers, Frank.

oldcutlass

The only info I can find is this 1964 schematic. Do you have a schematic that shows what you have? You aren't mistaking the horn relay on the top of the page as it has a green wire?

oldcutlass

Ok, I found one... Although for a F85

FrankieB

Yes, that F85 diagram you posted shows the warning light relay I have, to the right of the alternator regulator and to the left of the horn relay. The diagram I've been working off in the 1963 service manual is much the same although laid out it a different manner.

I'd never come across a separate unit for the warning light before, on the car it is tucked away behind the horn relay on the drivers side inner wing.

By the looks of the 64 diagram, it was done away with and the light is powered by the brown wire direct from the VR as you stated earlier.

I was dreading having to rewire the whole circuit but fortunately I should be able to repair my mistake without too much drama.

Cheers,

Frank.

MDchanic

Here is your schematic.

The red wire from the alternator light relay also goes to the regulator and to the BATT terminal of the ignition switch.

You should really get an original Service Manual.

- Eric

FrankieB

Thanks Eric,

Yes I do have a 63 service manual, (worth its weight in gold) and that's the diagram I've been working from and caused me a bit of confusion.

It looked to me like the VR and WLR red wires join together, and then go to the splice, but when the protective tape is off, they're two separate wires.

The red wire from the WLR is patched in from the front, and the VR red wire goes out of the back towards the firewall with all the others.

I've taken a snap of connection with the tape removed.

Thanks again.

MDchanic

Doesn't matter - they're all connected together.

I believe that the red wire that burned was an 18ga wire, and the rest are in the 10-16ga range, so you essentially burned up a fusible link, and just need to replace it, which should be easy now.

Be sure to check adjacent wires in the harness for burned-through spots in the insulation, which could short to something later.

- Eric

FrankieB

Eric, you've been reading my mind!

When I was under the bonnet before, I noticed a number of different gauge wires and pondered their significance. Most likely I would have just gone ahead and replaced it with 'something that looked similar' without realising it had any importance. Thanks for pointing this out for me.

I have to say that without this website, the people who share their invaluable knowlege, and the vast amount of information available in the different sections, I'd never have been able to get the old girl back on the road.

It took it for its MoT test last week and it passed with no advisories. I mailed all the paperwork away and I've had the registration documents back yesterday. It has been issued with an age related registration number and is now legal to drive in the UK. All I have to do is fit the number plates that I ordered yesterday when they arrive. To say I'm looking forward to driving it is an understatement!

I started a thread in 'Full Size Car' section but haven't updated it for a while, so I'll be adding to it with a few photos and a bit more about what I've done etc.

Many thanks once again,

Frank.

oldcutlass

Glad you got it fixed and can now enjoy.