378TS day running light issue with lamp replacement
Some of this may be a lack of not understanding how automotive elect systems work but I'm stuck. One D/L lamp went out .I bought a new one .Replacement didn't work but works on other side. I tested the socket harness and got 12v .I bought 2nd harness, thinking lamp connection might be weak .I put tester probes back into original socket to determine which wires to pair up to new harness. I plugged in new lamp into new harness and took bared end of new harness wires and made alternate contact with tester probes still in old socket. Not only did lamp not light but the 12v I had at socket went down to 0.
Can anyone help me out here I half expected if I had 12v replacement lamp would work in one of the 2 positions