I have 1990 gmc c1500 has no power to the fuel pump I’ve ...

I have 1990 gmc c1500 has no power to the fuel pump I’ve replaced the fuel pump,relay and the fuse still nothing what else do I need to buy Mechanic's Assistant: Is the power loss consistent, or does it fluctuate? No fuel...

I have 1990 gmc c1500 has no power to the fuel pump I’ve replaced the fuel pump,relay and the fuse still nothing what else do I need to buy Mechanic's Assistant: Is the power loss consistent, or does it fluctuate? No fuel Mechanic's Assistant: Are you fixing your Relay yourself? What have you tried so far? Yes I’ve fixed it

Automotive Expert
Hello and welcome! My name is [and I can assist you with your question. I am a former master tech and I have worked in this field for 20 years. I specialize this type of problem you are experiencing so I am confident I can assist with this issue. I am sorry you are having this issue and I understand this can be frustrating so I will try my best to help.](//www.justanswer.com/car/expert-amedee/) [While we are working on this issue together, please allow up to 30 minutes (or more) between replies as I might be online helping other customers or offline spending time with family. Please understand I can only see what is on this page and what you have already shared with me. Please keep in mind, I don’t know the history of the vehicle and I don’t know your mechanical ability, however, I will try my best to help.](//www.justanswer.com/car/expert-amedee/) [The phone call prompts are automatic and are coming from the web site, not from me. If you would like to speak on the phone, please request a phone call on your end and I will call you right away.](//www.justanswer.com/car/expert-amedee/) [I am going to start by asking some basic questions to get caught up to where you are at with this situation so I can assist you in a timely manner and provide you with the most accurate and relevant information. I appreciate your time and patience while we are working together on this matter.](//www.justanswer.com/car/expert-amedee/) [My goal is to provide you with a pleasant experience and ensure all of your questions are answered. Please reply back at any time so I can fully answer or address any questions or concerns you may have.](//www.justanswer.com/car/expert-amedee/) [_Please download or save any documents or images I may send you as they will automatically expire after 7 days._](//www.justanswer.com/car/expert-amedee/) [Can I start by getting your first name? Thank you](//www.justanswer.com/car/expert-amedee/)
Automotive Expert
Without knowing all of the information like the vehicle history, the components that have been tested or replaced, the results of any tests that need to be run and without being there myself looking at the vehicle, it is hard to say exactly what is going on. I can only give you a general answer, but I hope this helps. Depending on your set up and engine size, you might have a hot handling fuel module and or fusible links located on the firewall under the hood. Some of these even have an inline fuse that powers up the fuel pump. You can start by checking for this hot handling fuel pump and checking for power to the fuel pump while cranking. If you have done this already and determined there is no power, check the fuel pump relay operation. If the relay was replaced, check to see if it activates when you turn the key on and when cranking the engine over. If not, check the inputs to the fuel pump relay. It needs two powers and one ground to operate. If you can read a wiring diagram, send me the VIN and I can send you a copy of the factory wiring diagram of the fuel pump circuit. Thank you so much for giving me the opportunity to help you. I really appreciate your patience through this process. My goal is to provide you with excellent service. If you have follow-up questions on this same topic, please use the reply box below. To start a new conversation with me on a new topic, you can [request me here](//www.justanswer.com/car/expert-amedee/). Glad I can help. Please let me know if you have any further questions. Thanks and have a great night! Best Regards, Customer/p\>

Well i drop the tank put brand new fuel pump in cause it wasn't turnin on still didnt work so i replaced the relay checked the fuse its good but im not sure how to check the in line fuseable links so i didnt the next best thing i hooked a toggle switch up to harness fuel pump comes on but still nothing coming out the injectorsVin# \*\*\*\*\*
Automotive Expert
Thank you. I’ll do some digging for you and reply back tomorrow. Have a great night!
Automotive Expert
Good morning sir. I did some checking based on your VIN. YES, this vehicle does use an inline fuel pump fuse and fusible links off of the junction box and possibly a hot handling fuel pump depending on your fuel system. I would recommend to start by checking the fuel pump fuse and the fusible links under the hood at the junction box. I have provided a wiring diagram of this circuit for you below. Click on the link. [https://www.dropbox.com/s/ow2xaiqg4ihnat5/fuel%20pump%20circuit.png?dl=0](https://www.dropbox.com/s/ow2xaiqg4ihnat5/fuel%20pump%20circuit.png?dl=0)
Automotive Expert
Hello sir.    If you have any further questions related to this issue, please reply back to me on this page.   Please do not start another question.

Fuel pump fuse is good the 20amp in line fuse looks good but I’m not sure
Automotive Expert
Ok then you need to check the fuse using a meter. You can also check for power in and out of the fuse or circuit using a voltmeter as well.

Okay I’ll just put a new fuse in it if that doesn’t work I’ll do that
Automotive Expert
Sounds good

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