Parsing Info to exe to clear the fields in Hashtag Tables - foreach

Question

I'm trying to clear the Fields with values defined in Hash Tables by parsing it to the ipmiutil.exe utility. The script output shows it clear the fields but actually it is not when I manually check it. To clear the Fields values, each of those fields used different parameters as below. Can someone check my wipe code and help with the fix.
This is what I tried and expected the Field Values to clear when found but it is not clearing
Chassis Serial Number = .\ipmiutul.exe fru -G " "
Product Serial Number = .\ipmiutil.exe fru -s " "
Product Asset Tag = .\ipmiutil.exe fru -a " "
Powershell Code:
$fields_to_wipe = [ordered]#{
"Chassis Serial Num" = "fru -G";
"Product Serial Num" = "fru -s";
"Product Asset Tag" = "fru -a"
}
$input = $fru | Select-String -Pattern $fields_to_check | Tee-Object -FilePath "X:\output\fru_result.txt"
Write-Host "Checking FRU Fields for WIPE"
foreach($field in $input)
{
$field = "$field".Substring(0,"$field".IndexOf(":")).Trim()
if($value -eq "")
{
Write-Host $field "is BLANK. WIPE Not Needed."
Write-Host "`n"
}
else
{
if($fields_to_wipe.keys -contains $field)
{
Write-Host "$field Need WIPING"
Write-Host "WIPING $field"
Set-Location "Z:\Tools\Ipmi"
$cmd = .\ipmiutil.exe + {$fields_to_wipe}[$field] + " " + ('" "')
}
else
{
Write-Host $field_to_check ":" $value
}
}
}