HELP! 1990 420 SEL Cruise Control Amp

['90MB420SEL]

I've got a '90 420 SEL and the cruise isn't working. Going to try and replace the AMP. I've taken out the AMP that was in my car (005 545 05 32) with the Coding module. I've found a replacement out of a '86 420 SEL (003 545 07 32) with no spot for the coding module. Will this one work without any problems?

I've check the Internet and have heard both ways, but need to know an honest answer. The '86 AMP is only $48 so that's a great deal if it would work.

Thanks!