Electrical system is dead

I have a 1971 E type 4.2 OTS. Yesterday, I started the car and it stalled, started stalled again and so on several times. After the fifth or sixth time the car ran well enough to try a trip to the gas station a mile down the road. I filled it up and tried to start it and nothing. No electrics at all.
After the tow home, I removed the battery and noted that the insulation on the large positive cable from the battery had some melted insulation just above the voltage regulator where it bolts to a junction along with several brown wires. The brown wires seem to be ok but the large black ones have melted insulation on either side of the bolt. I plan to test the voltage regulator, ignition switch and starter, but wonder if anyone has any other suggestions before I reinstall the battery. By the way, the battery shows a charge of 12.8 volts after removal.

First thought to me is to check to make sure the ground from the battery is clean and making good contact at the body. The fact that the small black wires have high current can indicate a poor to non existent proper ground.

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I would check both the battery ground AND the positive post for corrosion. The positive post is the source of a lot of mischief, and often overlooked. Also make sure that the engine/body ground is good. This is usually a strap from the right side of the engine.

At this point, you also need to check the full length of any damaged cables for melted insulation. You should probably replace, not tape, any wires so damaged.


Since my last entry, I have replaced the positive battery cable and the long cable going to the starter. I also cleaned the brass threaded rod that forms the junction and noted that the nuts holding the cable eyes were rusty and somewhat loose. My guess is that this was the cause of the problem. At first only the lights worked but the rest of the system has come back and everything seems normal. The alternator still works and the voltage regulator seems to be working too. Thanks for your suggestions everyone.


Hey, Pete, good to hear you have this issue sorted out. Just a suggestion, you might want to consider buying a replacement terminal post or at least swapping over to brass hex nuts to avoid future rust issues at the terminal post like this one:

And if the wiring connections on the post are exposed make sure for safety reasons to cover those hot wires on both sides of the post with a pair of rubber boots - often these have deteriorated over time, removed but not replaced.

Battery_Cable_Boot C4650


Excellent suggestions. In my case, the rubber boot melted at the terminal post or junction and the local guy who made my replacement cables didn’t have any. Thank you.

This seems like a good time to interject, install a battery cutoff switch while you’re at it. You know the old saying “an ounce of prevention…”


The saga continues. After some very short “test” drives, the starter refused to turn the engine over. When I turned the key to the start position, all I got was a click. I removed the starter (and a whole bunch of other stuff) and took it to my local guy who rebuilds that sort of thing. He told me no parts were available for my model starter and I ordered and installed a High torque starter. When I turned the key, nothing. I started tracing the wires from the ignition switch to the starter relay and found that it, too had been very hot at some point. Wish I had looked here first. I bought a new 30 amp relay at my local parts store and installed it. No joy, but I found out that if I turned the key about half way through the start position, the engine turned over, I’m assuming the ignition switch is bad, but I’m beginning to wonder if I’m just throwing parts at the symptoms and missing the real cause of the problem. Any ideas? By the way, I have followed all the above advice except for the battery switch. So far, I’m removing the negative terminal when I’m away from the car.


It sounds like you have found the problem, the ignition switch. You should be able to confirm that the ignition switch is bad with the multimeter. Do you have one?


I tested it with a test light on the white and yellow wire that goes to the relay. The light only lit on the way back from the full start position.

I have had a few ignition switches fail on me, two in my XJ6s and one in my 1969 E-Type. The symptoms were at first intermittent electrical issues that then became permanent. Once permanent it was easy to sort out with a multimeter that the ignition switches were not doing their job properly and components downstream were affected. If I were you I would remove and replace that ignition switch and that should solve your problem.
BTW, did you notice if your ignition key was very hot to the touch? I wonder if something like failing cooling fans may have contributed to the ignition switch failing. I suspect that may have been the case in my E-Type about 12-15 years ago. One cooling fan was failing and blowing #6 fuses. While I was trying to figure out why the #6 fuses were blowing I noticed my key was hot to the touch when I removed it from the ignition switch. Then the ignition switch failed and shortly afterwards one of the cooling fans failed. Once I installed a new cooling fan and a new ignition switch my electrical issues went away and no more blown #6 fuses, cooling fans worked as they should, and the key was no longer hot to the touch when removed. Although it always feels a bit warm now when I remove it from the ignition switch.


New ignition switch is in, and it started beautifully and then it quit running because the fuel pump was not running. There is no power at the fuel pump. I have to think the fuel pump relay is bad. Does anyone know where it is?

Double check to be sure you reconnected the wiring to the new ignition switch correctly?

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The fuel pump doesn’t draw a whole lot of power so doesn’t have a relay. I would expect you have either a bad ground or need to take the cap off and clean up the points, most likely the latter.

The fuel pump isn’t fused it is connected to F6 along with so many other things including the ignition. You would definitely notice other power failures. Verify there is power to the pump with the switch on. For some reason after sitting for the winter my fuel pump didn’t work, it lost ground somehow. I supplied another ground wire and drove off into the sunset.

I’d check the easy stuff first. Are you getting power to the fuse that feeds the fuel pump; fuse #6, IIRC?

I think the power for that fuse comes from one of the terminals on the ignition switch.

A good old-fashioned incandescent test light is the best way to look for 12V on a non-electronic car as it draws enough current

Go around and look for 12V

All Earths should also be double checked

I did not think the fuel pump was fused

rule out all things before replacing the ignition switch

In my opinion, its a good idea to relay headlights in particular, as in most older vehicles, that current goes through the ignition switch

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Yes, correct, poor wording on my part. On my wiring diagram there is a wire that comes from the ignition switch to fuse 6 and that also feeds the fuel pump before the fuse.

Gentlemen, there is no power at the fuel pump. There is a good ground. If I power the pump with a 12 volt battery, the pump runs. Fuse six is good as well as all the others and yes, the new ignition switch is connected properly which is the reason I assumed there was a relay involved.

It’s supposed to be a white wire directly from F6 to the pump and not connected to anything else. It doesn’t actually use F6 its just attached there to get 12V from the ignition switch. You might wiggle the white wires at F6 to make sure they’re all tight. There is one connector shown on the white wire between F6 and the pump, you can try to track down that wire or simply install a new wire from F6 to the pump. If I were doing it I’d put an inline fuse in that new wire just for peace of mind.

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