02 bravada I do not have a fuel pressure gauge, can I verify problem with fuel pump without guage?

Where is the fuel pump relay located on a 2002 Olds. Bravada?
How do I test it using a multimeter?

Thanks for any help!!

The best I can find is it's under the hood inside the fuse panel.
If it's a 2 prong, connecting the leads of your DVOM to the prongs, set it for 20K ohms and you should see 0.00. If the relay is bad, you should see 1 .

Someone must know the location of the fuel pump relay on this vehicle. Please someone answer so I can get this running!!

Thanks

Thanks for answering, the vehicle is not here, but I will look under the hood for the fuse box and see if it has a relay for the fuel pump under there when I can get to it.. It is black and has 4 prongs right?

The best I can find is it's under the hood inside the fuse panel.
If it's a 2 prong, connecting the leads of your DVOM to the prongs, set it for 20K ohms and you should see 0.00. If the relay is bad, you should see 1 .

I don't know. The pics I saw looked like 2 prongs.

You're right dddaaa,

Here's a coupla pretty good pics, enlarge them to see which prongs go to the coil and contacts.

http://www.1aauto.com/1A/Electrical/Oldsmobile/Bravada/1AACD00049/412531?utm_campaign=gb_api_nobr&utm_medium=comparisonshopping&utm_source=google_base&utm_content=ACD

It has 4:
http://static.1aautoimages.com/partimage/ACD/1AACD00049/main.JPG (http://www.1aauto.com/1A/Electrical/Oldsmobile/Bravada/1AACD00049/412531?utm_campaign=gb_api_nobr&utm_medium=comparisonshopping&utm_source=google_base&utm_content=ACD#TB_inline?height=620&width=890&inlineId=myOnPageContent)
http://static.1aautoimages.com/partphoto/ACD/1AACD00049/middle_1.JPG (http://www.1aauto.com/1A/Electrical/Oldsmobile/Bravada/1AACD00049/412531?utm_campaign=gb_api_nobr&utm_medium=comparisonshopping&utm_source=google_base&utm_content=ACD#TB_inline?height=620&width=890&inlineId=myOnPageContent)
http://static.1aautoimages.com/partimage/ACD/1AACD00049/small.JPG (http://www.1aauto.com/1A/Electrical/Oldsmobile/Bravada/1AACD00049/412531?utm_campaign=gb_api_nobr&utm_medium=comparisonshopping&utm_source=google_base&utm_content=ACD#TB_inline?height=600&width=890&inlineId=myOnPageContent)
http://static.1aautoimages.com/partphoto/ACD/1AACD00049/small_1.JPG (http://www.1aauto.com/1A/Electrical/Oldsmobile/Bravada/1AACD00049/412531?utm_campaign=gb_api_nobr&utm_medium=comparisonshopping&utm_source=google_base&utm_content=ACD#TB_inline?height=600&width=890&inlineId=myOnPageContent)


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I don't know. The pics I saw looked like 2 prongs.

I do not know how which prongs to connect to my multimeter.
Thanks for helping

You're right dddaaa,

Here's a coupla pretty good pics, enlarge them to see which prongs go to the coil and contacts.

http://www.1aauto.com/1A/Electrical/Oldsmobile/Bravada/1AACD00049/412531?utm_campaign=gb_api_nobr&utm_medium=comparisonshopping&utm_source=google_base&utm_content=ACD

If they're numbered like the one in the pics, #85 & #86 should show a value higher than 0.00.

If there's a 1 by itself, that means the circuit is open and relay coil is junk.

3 of the prongs are at the corners but one is not all the way out to a corner.

Check for a fuel pump fuse too.

The #87 prong is the odd placed one. It should show an open circuit against any of the other 3. If it shows closed, it's a welded together contact and the pump would run constantly.
The #30 is the + power prong. It looks like it should show a value when connected to #85 or #86.

All help gratefully accepted.

I am confused, I connect my multimeter neg (black) lead what on the relay and the pos. (red) lead to what and what setting should be on the multimeter? I need step by step directions please.

Thanks for helping!!


The #87 prong is the odd placed one. It should show an open circuit against any of the other 3. If it shows closed, it's a welded together contact and the pump would run constantly.
The #30 is the + power prong. It looks like it should show a value when connected to #85 or #86.

All help gratefully accepted.

Using a multimeter, how do I test for voltage at the connections at the fuel pump? What setting do I put the multimeter on?
What leads under the car where the plug goes into the fuel pump do I connect the red and black multimeter wires?

Thanks for helping!!

The Bravada makes no noise when the key is turned at the fuel pump (listened with gas cap removed and key turned). My conclusion is it is a bad fuel pump, bad relay or bad fuse. I am going to switch relays (put A/C one in) and see if that fixes problem. After that I do have a voltemeter and am waiting on how to use it at the fuel pump connections. Can I just remove the fuel line hose somewhere, turn key and see of fuel comes out, therefore pump ok?? I really do not want to buy a fuel pressure gauge. Please help!!

The Bravada makes no noise when the key is turned at the fuel pump (listened with gas cap removed and key turned). My conclusion is it is a bad fuel pump, bad relay or bad fuse. I am going to switch relays (put A/C one in) and see if that fixes problem. After that I do have a voltemeter and am waiting on how to use it at the fuel pump connections. Can I just remove the fuel line hose somewhere, turn key and see of fuel comes out, therefore pump ok?? I really do not want to buy a fuel pressure gauge. Please help!!


you can check the fuse #10,relay is in engine compartment f/box
the gray wire on relay feeds pump
http://www.autozone.com/autozone/repairinfo/repairguide/repaiguideOverlay.jsp?src=http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0996b43f/80/24/09/b3/large/0996b43f802409b3.&imageType=gif&imageName=Fuel Controls - Fuel Pump Controls and Fuel Injectors(c) (2002)

Thanks for the answer (been waiting on someone to answer)!!
If I just switch the A/C relay (a/c works) with one for fuel pump, and the same problem happens, how do I check at the fuel pump using voltmeter (please say what setting on voltmeter and what wires at fuel pump to put + and - probes.)??

you can check the fuse #10,relay is in engine compartment f/box
the gray wire on relay feeds pump
http://www.autozone.com/autozone/repairinfo/repairguide/repaiguideOverlay.jsp?src=http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0996b43f/80/24/09/b3/large/0996b43f802409b3.&imageType=gif&imageName=Fuel Controls - Fuel Pump Controls and Fuel Injectors(c) (2002)

Thanks for the answer (been waiting on someone to answer)!!
If I just switch the A/C relay (a/c works) with one for fuel pump, and the same problem happens, how do I check at the fuel pump using voltmeter (please say what setting on voltmeter and what wires at fuel pump to put + and - probes.)??


the gray wire at f/pump is the feed,with meter set to dc volts there is a couple settings ie.. 10,50,100 you want the setting thats over but the closest voltage you are supposed to have.in your case its a 12v system so the closest scale on your meter is probably 50v(hope that this makes sense).
put the red lead to the gray wire the black to any ground.remember the
pump only gets power for a couple of seconds then shuts off if the engine does'nt start

Thanks for the info and link inafogg !!!

dddaaa, fuel pressure test kits are around $10 at Harbor Freight.
You'll have to locate the Schrader Valve though, I'm not familiar with 2002 & up.

Thanks for the info and link inafogg !!!

dddaaa, fuel pressure test kits are around $10 at Harbor Freight.
You'll have to locate the Schrader Valve though, I'm not familiar with 2002 & up.
Thanks for all the help everyone! I might see if any fuel comes out of hose when turning key to start position. (Therefore fuel pump works), without buying a fuel pump pressure gauge. I am getting NO noise from fuel pump when turn key so I think its the fuel pump.

Without proper testing tools you will end up spending more money on parts that do not need to be replaced. Rent a fuel pressure gauge from a parts store if possible. You need 50-57psi. Watching fuel run out of a hose will not confirm this. Use a test lamp across the gray and black connection at the pump to present a load. A meter may read 12volts with a bad connection up stream but enough current may not make it through the connection to run the pump. If you have a bright light with the key on that goes out after 2 seconds the relay is working fine. It should also stay lit while you are cranking the truck. If you have good power and zero or low fuel pressure the pump is probably faulty. Especially if the truck will start on a carb cleaner of some sort. Caution: when probing terminals do not force anything oversized into the terminals or they will be ruined. Use something that will fit in snugly without spreading the female terminals.