Blinks three times

My goodman furnace does not ignite the HSI, and the board blinks three times. Is this the pressure switch or rollover, or perhaps something else

My furnace is a Goodman GMP 100-3

3 blinks is end switch closed without inducer on.

Check venter end switch.

Also see the back of the blower for a wiring diagram with the blink codes listed.

I changed the pressure switch, and still got the three blinks. So I disconnected the tube and sucked on it to close the pressure switch, causing it to ignite the HSI. The inducer is running but apparently not creating a vacuum to the pressure switch. Could this be clogged? Do I need to take off the inducer and clean that port?

Could this be clogged? Yes but you might check the connecting tube for cracks first.

As it turns out, the inducer on the unit itself was not working. There was a secondary inducer that was causing it primary inducer to spin, but it was not coming on. I have changed the primary inducer, and now cannot get the primary inducer to work. What is the line voltage on the primary inducer. I am reading around 5vac between the white and black lines. What should it be.

If I am not mistaken the inducer runs on 120 volts. How about posting a correct model number so we can check.

The model number is GMP 100-3, and it is about 10 years old

120 volts is the answer I found

When I pull the wires off the vent motor mounted on the furnace, I measure about 5vac between the black and white wires. So would the problem be in the circuit board? According to the schematic, I should read 120vac. In the schematic, there is also a power vent relay. Is that on the board?

In the schematic, there is also a power vent relay. Is that on the board?

Yes and it is possible it is defective.

If that is on the board, and defective, does that mean I have to replace the whole board?

If that is on the board, and defective, does that mean I have to replace the whole board?

Usually that is the solution since the relay is usually soldered to the board and not easily found at radio shack.

Usually that is the solution since the relay is usually soldered to the board and not easily found at radio shack.[/QUOTE]

Replaced the whole board, and now enjoying heat once again. Thanks for all your help, you have been great.