My 84 truck is wired for a 4 pin module and I tried to use a 5 pin I have around. would not work. the same 5 pin module would work on my duster which was wire for the 5 pin. my duster will also work with a 4 pin. So what I have found is that a 4 pin will work with most systems but a 5 pin will only work in a system wire for 5 pin.
