I'm having some trouble installing a new aftermarket stereo into my 84 244. thought it would be easier than on the 940, which was no trouble at all. the problem seems to be the constant power source that comes from the battery (yellow on the wiring harness). The only way I can get the unit to work is if I splice the two positive cables from the harness (Y + R) into the positive wire from the ignition that switches on with the key. i can use the stereo but it erases all of my preset stations when the car is turned off.

the existing constant power line (orange) does not appear to be original. I think it was added to make the previous unit work. The meter says this wire is getting 12 volts with the key off, so I can't figure out why it isn't working with the new unit, I also pulled the new-ish one from the 940 and got the same result--no power to the unit unless I put both Y and R into the + ignition wire (it is black in the car's original harness. Currently the orange wire is spliced into a red wire at a terminal directly under the the steering column--I'm not sure where this goes to.

My question is whether there is a better place to splice a wire for the stereo constant power supply? Also, could part of the problem be that the existing (orange) wire isn't a sufficient gauge--it is fairly small whereas the yellow wire on the harness is heavier? It doesn't make sense to me why it is getting 12v but not powering up the stereo.