First off is the print card damaged? If all the wires are not connected, you will get an error code as the unit on power up runs a self test. Have you tried to plug in the 2 wires back into the igbt(s)? The color coding on the wires have a rhyme and resoning. From left to right and starting on the left steering IGBT, they will be in paired alphabetical order when connected( first letter of wire color). for example....... Blue Red, Pink White, Green Yellow, Black Orange if i remember right. I dont dont have a service manual with be but i think you see what i am saying. If the truck has not been tampered by anyone when it went down then the simple reconnect should correct the issue. If not then it could be safe to say that it is possible the connectors that were unplugged were not installed properly on the gate pins and have possibly arched and overheated the gates. This could cause a short in the transistors. But usually when a short is on the gate side, it blows the print card. Let me know the order the wires were plugged in.

Thanks RCAV8TOR much appreciated for your help. I do have limited experience in electrical repair I did what you said and there were no melted wires or over heating. However of the 8 wires coming out of the steering transistors some of them only had 1 of the pair plugged in. So only 6 connections were plugged in instead of the 8. Could this have been the cause of the problem and damaging the print board? Also some additional info I was notified of after
- The previous person that tried fixing this had made the owners of the forklift purchase a new board already and the forklift worked fine for about 10 mins once the new board was in. But after that the same problem came back up. So my guess is that those 8 connections that were supposed to be all connected caused damage to the new board?

I am assuming you have knowledge in electric forklift repair. If you have zero experience with one of these, i highly suggest to call your local Unicarrier dealer. If feeling a little spunky, then i would first off make use of a camera and take pics of what you are about to disaasemble. Locate a static strap ( If needing to know how to use static strap, just walk away and call your local Unicarrier dealer)before proceeding in removing the print card from unit. Disconnect battery and remove all connectors from the metal print board box. Remove card and metal housing. Carefully inspect the bus bars for any overheating and possible wire melted to them especially around the PS contactor. If all looks good then check upper right hand of the the control panel. There you will see 8 wires from 2 transistors that plugs into the upper right hand corner of the main print card. These are the IGBT's for the steering. The 530 code shows that there is a short in the PS circuit thus the inspect for melted wires. I rather see an open code ( 531 ) than the 530 short code. You can remove the cover to expose the main print card. Look upper right hand corner of card where the 8 wires comes together in a plug and is inserted into the main print card. With a mag glass, look for any small components that has blown out ( small chips ) on the card. If any are found blown then you will need a new or refurbished main print card, new set of igbt's and a ps motor check. Order the igbt's in a set from Unicarrier dealer. The reason is they are matched for same resistance reading. The ps current sensor is basically a resistor that is ceramic and is located beneath the ps contactor and it will have the Ohms value printed on it. If uncomfortable with or have never trouble shot a system as this, i would suggest calling a dealer. These parts are expensive and little wisps of smoke out of the main print board can mean over a grand in cost for a new one. The IGBT's can be costly also. Been awhile since i have worked on one of these trucks as many are being replaced by newer models. Hope this helps.