1948 Jaguar sedan voltage regulator

I am re-wiring my 1948 sedan (Mark IV). The voltage regulator is on the firewall, just below the 2 fuel pumps. This seems like a gas fire waiting to happen. I welcome any opinions regarding moving the voltage regulator above the fuel pumps or leaving it where it is.

Hi Dennis,

My MKIV is being rewired at present. The voltage regulator we have was fitted under the fuel pumps until around July 1948 when it was relocated to the scuttle - far more sensible! Many people fit a drip tray under the pumps to catch any fuel weeping. I’ll see if I can come up with a photograph. If you had major leak nothing would stop a fire I fear. The pumps and fuel pipes just need to be checked every time you check the oil, I guess?


1 Like

One little occasional drop wouldn’t make much of a fire, probably would evaporate and dissipate in the fan air stream before it ever got inside the regulator cover.
I rebuilt my pump and I know it doesn’t leak so I don’t worry about it.

You could seal around the cover if you want to.

A large leak or a hose letting go is of course different.
But you’re supposed to look under the hood and check those things every so often.
There are more sparks going on inside the distributor cap than in the voltage regulator.

Thanks for the information. I am weighing keeping it as is, or cutting a hole in the scuttle and moving the regulator. I am generally in favor of keeping things the same.

I think I’ll leave it as is. The car was last on the road in 1960. If I get it done I’ll check for leaks consistently.
Take care

Please don’t do that.

That’s a much better solution, albeit with a drip tray fitted for peace of mind.



Also even though I like to keep things original, if you need to tinker/rebuild the charging relay, putting in a solid state unit would ensure you would not be getting too many sparks or a short.


That’s just heresy! :grin: I’m shocked that you could suggest such a thing! :wink: In all seriousness, the drip tray is the best solution.


I’m in the “heresy” camp. This is for my SS100, but I have the same device in my XK120 with several years of driving and maintaining a charge…


My suggestion is DON’T relocate it. You will have big problems with the lengths of wires. The only arcing is on the cut out contacts under the cover - not an easy place for petrol to reach. Fitting a drip tray is the simplest safeguard without altering the car. I have a '47 with the same configuration and I don’t intend to alter anything.


1 Like

A very clever man I know has made these wonderful drip trays for a MKIV.


1 Like