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95 gmc 3500 with a 350 fuel pump relay only getting 1 power feed but even
95 gmc 3500 with a 350 cid. The fuel pump relay is only getting power to the load side not the control side. Fuel pump works when you connect 87 & 30. Supplying power to the control still won’t operate pump. What is next move? Computer? Thank you in advance for your time.
GM relay
85 = 12v (control side from PCM)
86 = ground
87 = 12v (load side)
30 = to fuel pump
KOEO
test light to battery positive touch 86. test light should light
test light to battery negative touch 87. test light should light
test light to battery negative touch 85. CRANK engine test light should light. if it does not, check for open from PCM to 85. if no open or short, its the PCM. hopefully not.
****DO NOT JUMP 86 TO 85 - YOU WILL FRY THE PCM ****
note: use TEST LIGHT to do testing.
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