TBI 454 fuel pump fuse? - Pirate4x4.Com : 4x4 and Off-Road Forum

WyoJeeper · 02-25-2009, 08:56 PM

I have an 89 3500 with a TBI 454. It keeps blowing the fuel pump fuse. Its a 20amp fuse. Even pops a 25amp fuse. Does anyone know why its poping the fuse? Bad fuel pump? Bad ground? I am not sure. Its my daily driver and I need to get it fixed. If its a bad pump I can swap it out no prob.
Thanks for any help.
Rick

the_experience3006 · 02-25-2009, 09:12 PM

Putting in a bigger fuse is NOT a good diagnostic technique, especially in a fuel pump circuit.

Test the resistance of the circuit. Put the ohmmeter on the power feed to the pump and battery negative. I bet you will find 0 ohms or nearly 0. The next question becomes whether or not it is shorted wiring or shorted in the pump which you will have to figure out on your own by ohming the connection at the pump itself.

WyoJeeper · 02-25-2009, 09:22 PM

Thanks. I am just trying to get it figured out. It happened as it was getting dark, didnt have my ohm meter. And about 50 miles from home. It sounds like my pump is bad, the wiring for the pump harness has given issues before on these trucks. Might just be time to replace the pump. I will check it in the AM.
Rick

02-25-2009, 08:56 PM	#1 (permalink)
WyoJeeper Registered User Join Date: Jun 2000 Member # 1040 Location: Oregon Posts: 432	TBI 454 fuel pump fuse? I have an 89 3500 with a TBI 454. It keeps blowing the fuel pump fuse. Its a 20amp fuse. Even pops a 25amp fuse. Does anyone know why its poping the fuse? Bad fuel pump? Bad ground? I am not sure. Its my daily driver and I need to get it fixed. If its a bad pump I can swap it out no prob. Thanks for any help. Rick

02-25-2009, 09:12 PM	#2 (permalink)
the_experience3006 Registered User Join Date: Sep 2006 Member # 80052 Location: St. James, MN Posts: 1,701	Putting in a bigger fuse is NOT a good diagnostic technique, especially in a fuel pump circuit. Test the resistance of the circuit. Put the ohmmeter on the power feed to the pump and battery negative. I bet you will find 0 ohms or nearly 0. The next question becomes whether or not it is shorted wiring or shorted in the pump which you will have to figure out on your own by ohming the connection at the pump itself. __________________ [QUOTE=abig84;9192789]i swear id be gay if it wasn't for all the gay sex that's involved[/QUOTE] [QUOTE=TexasBlake;10305687]She's not that hot. I was just looking for a quick lay and she all wanted to like go on dates and shit. [/QUOTE]

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

02-25-2009, 09:22 PM	#3 (permalink)
WyoJeeper Registered User Join Date: Jun 2000 Member # 1040 Location: Oregon Posts: 432	Thanks. I am just trying to get it figured out. It happened as it was getting dark, didnt have my ohm meter. And about 50 miles from home. It sounds like my pump is bad, the wiring for the pump harness has given issues before on these trucks. Might just be time to replace the pump. I will check it in the AM. Rick