Home Forums General Discussion Technical Questions Dover composite help!

Hey everybody. I have a Dover composite I’m working on that started having an issue where in auto it would pick the. Rake and the run down at about 1 fpm until it hit the final. Couldn’t force the car up or run it on inspection. The only way to hit it up was to pick the brake and drift it. Then it would just do it all over again. During the troubleshooting process the motor and generator armatures megged poorly and the decisions was made to replace them. They’re in and the generator spins but im still having an issue but now the car doesn’t run down on auto it just drifts up with. No power. Same with inspect up or down. It just drifts when you give it command. CFC and FCP relays aren’t pulling in and I’m struggling to hunt down why. I’m working off several sets of close but not made for the job prints and a good number of the relays I have aren’t even in the prints. I did record all the actions of the other car in the group while on inspection to compare to this car. Any help or ideas would be greatly appreciated.

You have a round about year of installation? Assuming you have ensured you are getting voltage to the motor?

Its a 74. It has voltage at a1 and a2 whe. Theres a demand

Do you have voltage at the motor shunt field.SH 1 and SH2?

So to run you need to have the P switch, The 10 relay,the DR relay, the MO relays. The 14 relay is the leveling shunt control, and 15 is the high speed shunt control. Also a a direction relay. You also need to have the motor shunt field. And of course the Generator Shunt field.If you have voltage at A1 and A2 the Gen shunt is providing it.SH1 and SH2 is the motor shunt field. hope this helps Good Luck.

Ok. I have 155 vdc across the motor shunt field and nothing across the generator shunt field currently. My old generator had wires gf2 and gf3 ties together as well as d2f and d3f which were supposed to be in the generator shunt and compensating field respectively. Those no longer exist on this generator so im guessing they're internal. Ill see if those relays are picked. Thanks for the info.

Also both these controllers have the 15 relay coil unwired. Its been a obstacle when it comes to understanding that high speed low speed circuit. The other car is running a soft start so not much help. Also ive double checked everything with an inspection down demand. Im getting about 6 volts on A1 and A2 the motor shunt field shows 260 volts and the generator shunt field shows nothing. I have all those relays except the 10 relay pulling. Can't seem to find a 10 relay anywhere except my 10a1 through 3 IBM relays. I ha e a 101 and 102 relay pulling if thats what you mean. Not sure what changed to cause me to no longer have real voltage on a1 and a2. Nothing is different than it was. I did note that t2/k1 and t3/k2 were backwards bu when I changed them around the generator spun backwards and I blew the dash pot in the motor circuit. So its back the way it was.

I would say you had better find the original Generator, and re-install it. if it is in fact bad, have it re-wound. you will not move without Generator shunt field.

Found what I believe to be a busted rf3 resistor. (Labels are all missing) changed it out and my gen field is back. Car is moving. Thanks for your help.