Cadillac Repair: 99 caddy escalade fuel pump module, ground circuits, wireing diagram

Question
3rd module r&r in a year.2 a/c delco 1 aftermarket in place now.(new). no power to pump for prime. relay also replaced,new a/c delco.no bad fuses found.  any ideas? thanks.

Answer
Hi Tom,

     You don't mention replaceing the fuel filter. If restricted it can cause an otherwise good pump to fail.

     Also in years past where the module harness plugs into the fuel pump the power terminal can overheat and spread due to excess current draw. Remove the harness from the pump and look at the terminals to make sure they are makeing good contact and aren't burned. Also look below the master cylinder at the C130 4 wire connector and make sure it is ok also.

    If they look good verify that the correct voltage is getting to the pump and that the ground wire is good. You will need a wireing diagram to trace the power and ground circuits to see where the proble lies. Ignition switches have been know to fail on 1 wire or work intermittantly such that it might take 2-3 key turns to get power and the next time it might not work.

     In looking at the service bulletins there is a bulletin number 04-06-04-088C dated 8/24/2006 that addresses repeat fuel pump failures and has connectors that are suggested to be replaced whenever a module is replaced. If you contact your nearest GM or Caddy dealer they can get you a copy of this bulletin and the required parts. I have no way of sending that info to you otherwise I would.

     Hopefully I have been of some help. Bill