Hi, and welcome to Just Answer. My name is XXXXX XXXXX I will help the best I can. I may need to ask questions to better understand your concern.
Do you have questions?
The same fuse for the starter relay also protects the fuel pump. If it is blowing the 20amp but not the 25amp fuse then there is too much current draw for the circuit. It could be the fuel pump or the wiring in the starter/fuel pump cicuit.
How do you check the wiring to the starteer/fuel pump? And how bad is it to use the 25 amp fuse?
The current draw needs to be checked which would require an inductive pickup since it is that high of an amperage. My suspition is that the fule pump is failing and drawing to much current since it is the only loafd device in the circuit. The starter relay could be the other one to check by switching it out with another relay of the same tyoe in the panel. It is a problem that needs to be addressed because the extra amperage draw can be too much for the wiring/connectors and could cause a fire in the wirting harness with the 25amp fuse. The circuit was designed with a 20 amo fuse and if 2-4 more amps are going through that circuit it is likely to overload them before the 25amp fuse blows.
You could take the fuel pump relay out and see if the 20 amp still blows when you crank the engine. If it doesn't then the problem is in the fuel pump circuit. If it still blows then it is in the starter relay circuit.
But this problem has been ongoing for 2 years and has just gotten worse - could a fuel pump be going bad for 2 years? It seems that it would already have gone bad if that were the case?
If it has ben ongoing then no. It may be an intermittent short circuit in the wiring harness that is blowing the fuse. This makes it even more difficult to find, but you could still seperate the fuel pump from the starter relay circuit by trying it withe the fuel pump relay out and the 20 amp in. Does it blow the fuse immediately or does it just do it whenever?
So I should take out the fuse going to the fuel pump and try to start it?
Are you blowing fuse #8 or #23 ?
I think it is #8 - it is front row 4th over from the left
Yes take it out and put the 20 amp in.
so take the 25 out and another 20 in that spot? this is the one that blows all the time
yes, but unplug the fuel pump relay and see if it blows when the fuel pump is eliminated from the circuit.
This is only a good test if the 20 amp constantly blows
how do I unplug the fuel pump relay? and where is it?
It is in the same box as the fuses under the hood drivers side. Should be marked on the lid.
ok going to try it
lower left corner of the picture
ok it started w fuel pump relay unplugged
DIdn't blow the fuse?
Ok plug it back in and see if it blows the fuse
started it twice and did not blow fuse
The problem is too intermittent then. There must be a short that is touching randomly that blows the fuse.
That make more sense but how do I find it?
And why does the 25 amp work?
The only way to find it is too go through the wiring harness and look for damage and pay close attention to the connectors for any terminals that look like the lastic melted inbetween pins. The 25amp must work because it is not a direct short to ground but possibly a short to another circuit in the harness or a connector that is adding current load to the starter/fuel pump circuit. If it blows when you start it it has to be in the starter side and if the car dies and it is blown it has to be in the fuel circuit side.
Only happens when I start the car, once started works fine and usually only blows once in awhile, but yesterday it blew 3 times and then again this morning
Ok has to be in the starter circuit. REfer back to the picture/wiring diagram that I posted earlier. Check out connector C113 really well inside and out.
light grey connector
Ok I can't find it but have never worked on a car before - so I need to print the diagram and find someone that can do this. Do you know a mechanic in San Diego to recommend?
Unfortunatley no, I am in Ohio.
Ok so if I get this checked then what?
If it is checked out they should be able to find what is causing the short and then it is a matter of a wiring repair.
Ok, thanks Tom! You were great. What part of Ohio? I have relatives in Dover?
Dayton north of Cincinnati and west of Columbus
Well hopefully this will help my problem I will keep you posted. Thank you