OK just picked up a 84 K30 6.2. Couldn't get it to start, got to checking and pulled glow plugs and 3 i couldn't get out ( i think from swelling,) the 5 i could get out, i tested and all bad. Bought new ones and out in. I see controller on lhs rear of engine, and relay on lh inner fender. no power to plugs, bypass relay and i have power to plugs, started once , warmed up, started again and again while warm, let it cool and nothing. iv read how to bypass relay with button, but seems all be 85 and newer style. What do I do? and help would be appreciated.
Oh and i bypass relay with a jumper wire i get power to glow plugs but wont fire? WTH is wrong or am i doing something wrong?

 

You can use this to get that swollen GP out: Accessories

 

should be a thermo sensor on rear of passenger side cylinder head that activates glows when below threshold temp.