Fine tuning: I suggest using a 56 Ohm resistor instead of the 47 Ohm. This higher resistance yields a brightness level that is closer to the half bright bulb test phase of all the other dash indicators when you're starting the car.

And for full disclosure, safety as your own risk kind of thing: consider using a 3 Watt resistor instead of 1/2 Watt. And for extra bonus points make it a flame proof resistor instead of the common carbon type. Such a resistor would be resilient enough to handle a sustained double fault condition: GPR is sticking closed and your dash glow indicator bulb wire is shorted to ground (no light).

Such a resistor would be too fat to fit on the underside of the printed circuit board for getting the cover back on the device, so you'd have to mount it elsewhere on the component side.

Just to be clear, a common 1/2 Watt resistor is sufficient for the single fault condition of GPR sticking closed. It does not have to be flame proof. Such a resistor will shine the bulb for an indefinitely long period without risk of heating up beyond its design point. It's only if you fear the bulb wire short existing at the same time.

But in my opinion with this mod in, you'd notice a non-working bulb pretty fast because each start cycle you'll be staring at it. If you get "no dash light" your car probably won't start - and it means your GPR has just gone bad, its 80A fuse has blown, or its control circuit wiring has gone faulty. OR the bulb has simply blown and your car continues to start fine down into cold weather, you just need to change the bulb. Acting right away in such a case will tell you what's up, test the bulb first: pull the plug on the GRP and apply +12 to the lamp indicator pin on the harness socket. No dash bulb? Change it, and recheck. Good bulb? Solve GPR issue.

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Cheers!
Scott McPhee

1987 300D