DIY bypass the charge lamp

[Largewon62]

 I am looking for a way to bypass the unreliable charge lamp circuit that is preventing charging on my 1987 Grand National.  I know that there is a way to excite the field using a wire from the waste gate solenoid, but have not found a definitive guide to doing it.

 Any tips would be appreciated.

[TexasT]

I'm all for the diy approach but I doubt you could buy the pigtails for what casper charges.
http://www.casperselectronics.com/cart/index.php?route=product/product&path=7_53_54_10_14&product_id=604It it was a no brainer for me to just send them the money.

[daveismissing]

I'm trying to remember if its the low side or the high side of that solenoid that is PWM'd.
A  ~470 ohm resistor to  a switched 12v source was the basic field fix, wasn't it?

[Largewon62]

 Thanks for that info. I am aware of the Caspers harness, but I work in the gas fireplace industry and with the unseasonably warm winter we've had, I must mind my pennies until my summer gig starts. At almost $60 shipped, I'd like to make my own if I can.

 I thought it was as simple as running a wire from the "i" terminal on the alternator to a switched 12v source like the waste gate solenoid?

[Steve Wood]

No, it needs a resistor in the line to drop the voltage a little.  Otherwise, the alternator won't last too long.  You can also just wire a instrument panel light bulb in series with the switched 12 volt feed.

[daveismissing]

Looked at the diagram-The ECM controls the ground/low side so the other terminal is 12v