i'm trying to replace my fuel sender unit on my 1972 142e and have a question.
I bought a used unit from my local volvo junk yard. I put it in my car and filled the tank up. The unit didn't register as full it only said that it was half full. My original unit registered it full but than when the tank got to half it went to empty. My original unit has a couple breaks in the fine wire that makes contact with the float wire so I know what is wrong with it. The two units have different numbers and now the junk yard is giving me a hassle saying that the unit they gave me worked fine when they gave it to me. The part they sold me has a set of numbers that are not the same as my original and I'm trying to get some information about the numbers to go back to the junk yard and either get a refund or the correct part. These are the numbers, The replacement is 42/1 followed by 687825. My original says 37/14 followed by 687826. Is there a difference and what can you tell me about these numbers and parts? Your help is needed so I can get this straightened out.

Thanks for any info,

Chef Blue