To answer my own question about jumpering pins 8 and 9 on card 1 together, and what card 1 actually DOES as far as the reverse relay control - from the card, it looks like it's a time delay circuit, so that if you flip from forward to reverse (or vice versa) too quickly, while the motor is still spinning one way, you don't suddenly reverse the field to point in the opposite direction. Is that correct? So, the reason I shouldn't just jumper 8 and 9 together is so I don't go and reverse the field too quick, which would probably give me a big induced current in the field winding, presumably frying a connection somewhere - probably on the relay. Seems like I could do that as a temporary fix (if I need to wait for some part to arrive so I can fix card 1), just making sure I give plenty of time between going from forward and reverse, to avoid frying relays left and right. I'll check though to see if I can determine what part on card 1 fried, to see if I can get it working without jumpering across those terminals (we have gobs of resistors and capacitors at work, so if that's all it is, I can "borrow" a 3 cent resistor or cap to fix it).
Mike -- -------------------------------------------------------------- Michael S. Briggs UNH Physics Department (603) 862-2828 --------------------------------------------------------------- On Sat, 5 Aug 2006, Michael S Briggs wrote:
Damn damn damn. Ok, it looks like I have a problem on card 1. With the speed lever in reverse (neutral), I get battery voltage at wire 41 (terminal 8) on card 1, but nothing on wire 39 (terminal 9) on card 1. So, card 1 ain't working properly. Hmmmm... could I for now just jumper them together? What exactly does card 1 DO as far as controlling the forward/reverse relay? It seems like it just passes battery voltage on to the relay - it comes into card 1 on wire 41, and goes out on wire 39. So, is there any real need to have it go through card 1? At any rate, unless someone says it's ok to jumper terminals 8 and 9 together (wait, didn't I just see someone say that? Or was that in the archives?), I'll try to find what part blew on card 1. Also need to determine WHY. Did card 1 fail, which then caused the new relay I put in to fail? Or, was the new relay bad to begin with, and due to it having some short across the coil, it caused a failure on card 1. Ah, the chicken or the egg.... :) I'm going to swap in one of the other relays. Mental note - but parts (such as replacement relays) from Harold, instead of cheap Chinese parts.... I guess I can also use this opportunity to put in that shiny new capacitor for the charger. :)I wonder if I can mow the entire yard with only forward speeds.... Thanks, Mike