Problem changing Maka validator with MEI on a Polyvend

[Bentrod]

Hello I'm a Noob to vending machines but I got a Polyvend PV6640 for free and with a $6 worth of connectors and a splice in the keyboard flex cable I have a fully functional machine.  The Maka validator works but rejects 50% of the time so I had a working 24v MEI VM2502 that I would like to replace it with.  I got a mounting kit, pulse interface power harness, and a 24v Maka to 24v Mars VN/VFM "Y" harness adapter from Capital Vending.  I hooked it up according to the pictures that came with the kit, powered it up and the Mei validator accepts the dollar, and shows $1.00 credit on the machine. The problem is that the validator will not accept any more dollars afterward.  The green arrows on the bezel does not flash and it won't take any more bills until I make a selection and use the $1 credit.  After the machine vends the validator bezel arrows flash and I can insert another dollar.

I've tried changing the pulse timing from short to long with no change. The 24v pulse interface cable only plugs into the bottom portion (12 pins) of the MEI 30 pin header connection.  Do I need another harness?  Maybe the Low Level Interface cable?  Doe anyone know which interface the Polyvend uses?  BTW the Polyvend is a 1993 Model. 

Thanks in advance,

Bentrod

[lacanteen]

According to my MEI bible, that should be a serial interface. You may try setting a phantom price (a non-existing selection) over $2.00

[Bentrod]

I figured it out.  The cable harness and connections were fine.  The issue was with the configuration, I just had to change the Escrow setting.  After that everything worked fine.

Thanks for the help

Bentrod