Hard Start Relay melting Starter Motors

[Blakefruid]

Hi all,
As it’s a bank holiday I thought I’d try and fix an old issue on my 1.6JX. I had a hard start relay fitted professionally a couple of years ago, but it seemed to melt starter motors, so the relay was removed and a jumper wire joined 85 to 87 re-making the original path.

So, I thought I’d start from scratch with all new, connectors, fuse, cable and a 40A Multi Use “53” relay from Brickwerks. As far as I know it’s all wired up correctly on the relay: 30-12V starter battery bolt, 85- Ignition, 86 -Earth, 87- Starter Lucar spade and all connections are clean and good.
It starts well, but with the relay in the starter just keeps spinning, rattling its bearings and doesn’t disengage once the engine has started, hence the melted stater motor. I refit the jumper cable (85-87) starts well and runs well.
So leave well alone I hear you say…well I’m just curious what’s happening, why and can I fix it?

Thanks for your help,
Cheers Blakie

[Aidan]

You do not need a relay in the starting set up, just have it as factory and sort the original wiring if needed, wiring diagram is readily available, the connection from the fuseboard should go directly to the starter

[Blakefruid]

Thanks Aidan, that's what I was thinking, just replace the 6mm red & black with new

[mioba]

No such a thing as a hard start relay. Why did you fit that.

you need to cure the underlying problem and go from there.

There is a Glow plug relay. But nothing on the starter system.

What engages the stater is the key in the spring position. Sure your ign switch isnt not the cause of the original problem.

just thinking aloud.....

[Simon Baxter]

No need for a hard start relay on a T3, petrol or Diesel.
If you have a "Hard Start" you have problems that need fixing not some snake oil sticking plaster.

Most of the time on a petrol the problem is the 35mm² (1.9l up to 85ish) or 70mm² (WBX 85 ish onward) front to rear battery cable that has corroded inside the rubber boot and insulation at the starter motor end.
Diesels in my experience don't struggle like the petrols do, the battery is much closer to the starter and less chance of a massive volt drop down the shorter cable.
It's all just usual checks, strip, inspect and clean/replace any poor connections such as engine earth cable, gearbox earth cable and the positive cable to the starter. Chop and re-terminate the solenoid exciter wire.

[cobblers]

It's not really possible for a relay to melt a starter motor unless it was holding the thing powered on all the time (which you would obviously notice)

As Simon says, you have a different problem that needs fixing.