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First a Code 54 - now no power


Magic071
02-28-2005, 12:10 AM
I tested my SES by jumping the ALDL and got an error code of 54. Changed the fuel pump and now I don't seem to have any electricity to the plug. Any suggestions and help would really be appreciated as I don't have the money to go to a mechanic.

1987 Blazer 2.8l V6


:screwy:

blazes9395
02-28-2005, 01:03 AM
No electricity to which plug? The ALDL? Either way check your fuses.

Magic071
02-28-2005, 01:41 AM
No electricity to which plug? The ALDL? Either way check your fuses.


I don't seem to have power to the fuel pump. I have checked the relays and at first I thought I heard them "click"...but now I am not so sure. I have checked all the fuses located under the dash and the ignition fuse. I am at my wits end as this is the only vehicle that I had running at this time. Could my battery not be putting out enough power to run the fuel pump?

blazes9395
02-28-2005, 02:03 AM
Check your connections at the pump. Make sure you have a good ground at the pump. But either way, its probably connections at the pump. Also, is the pump new, are you sure it is working?

ricksza
02-28-2005, 04:55 AM
You do realize that when you turn the key on, the fuel pump only has power for a few seconds until the engine starts.

blazee
02-28-2005, 08:40 AM
Are you sure you had power to the plug when you started? A code 54 indicates a problem with the fuel pump circuit....your old pump could have been good.


Check the fuses and the relay. I don't know the relay location on a 87 but someone on here can tell you, try swapping it out with one you know is good. If it works then replace the bad relay.

Magic071
02-28-2005, 09:50 AM
Thank you. Yes, the pump, old and new, seem to be good. How do you test a relay properly? My book says to turn on the vehicle....but that isn't possible...the truck won't stay running.

Magic071
02-28-2005, 10:01 AM
I am also thinking that there may not have been power to the fuel pump in the first place, but I didn't check for that. I just dropped the tank and put in a new pump. $700 for a new pump just to find out that the old one runs fine.

blazee
02-28-2005, 10:16 AM
Your book is probably telling you to turn the key on without starting it so you can listen for the pump to prime.....if it comes on there is no reason to check the circuit....if it doesn't you should test the circuit....yours isn't coming on, so you should test the circuit.

1) check the fuse.... you said you did that but go ahead and check again.

2) test the relay: The best way (recommened by Haynes) is to just swap it out with another one that you know is good.

3) inspect the wiring for damage.

Magic071
02-28-2005, 10:29 AM
Everyone says "check the fuse"....I have checked all the fuses and there is no particular fuse for the fuel pump. I have fuses for the ECMB and ECM, Ignition, etc. But not one specifies the fuel pump, fuel relay or fuel injectors. Should I just check all of the fuses again?

blazee
02-28-2005, 10:33 AM
It is probably the ecmb fuse, but it doesn't take long to check all of them.

blazee
02-28-2005, 10:35 AM
I'd say more than likely it is the relay.

dolluper
02-28-2005, 10:44 AM
When you turn your key on you will hear a click under the hood this is the relay working no click no working Test wires at relay orange/black sends to ECM signal and oil pressure switch- problem with this wire ECM shuts pump down some models have a inline fuse also, check ground is good on relay also

Magic071
02-28-2005, 10:49 AM
Ok.........ECMB fuse is good but I get nothing from the relays.....no clicking, no nothing. Maybe that is the problem. I will let you know as I am on my way (walking) to the auto shop for the $80 relays.

blazee
02-28-2005, 10:56 AM
Don't buy a new relay just swap it out with one from something else on the truck

Magic071
02-28-2005, 10:59 AM
I only see the two relays....there doesn't seem to be any others.

blazee
02-28-2005, 11:01 AM
Try one from the A/C or something.

blazee
02-28-2005, 11:07 AM
There is no reason to buy a new one until you know the old one is bad......remember the pump? :)

Magic071
02-28-2005, 11:12 AM
Okay....the other relay doesn't fit...it seems to be an opposite plug....it is backwards compared to the fuel relay. I don't have a/c or anything...this was the bare minimum packaged vehicle and I bought it second hand.

Magic071
02-28-2005, 11:19 AM
I have pwr at the orange/blk wires, but also the green wire...which is very weak. Any suggestions?

Magic071
02-28-2005, 11:27 AM
I have checked the orange/blk wires...they have pwr. But the green one does too, only just a small amount of power.

Magic071
02-28-2005, 01:30 PM
The relay is working...still don't have power to the plug that plugs into the fuel pump. I am mapping the wiring to look for shorts.

blazee
02-28-2005, 01:47 PM
If the relay is clicking then you need to test it's contacts. There should be 4 wires going to the relay.
With the key off, one will be hot and three will show no voltage.
With the key on three should be hot and one will show no voltage.

If only two show 12 volts with the key on, the contacts inside the relay are bad.

dolluper
02-28-2005, 04:24 PM
Your relay wires orange/black=ECM+oil switch
green=mod
black=ground
gray or tan/white ?=power to tank should match at tank either or

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