Old Topic it seems: EFI fuse keeps blowing

M

MA71

New Member
Nov 5, 2008
52
0
0
Seattle, WA
wtf I didnt realize there was more than one I guess.
The TSRM lists only the "fuel pump relay" and the circuit opening relay, and the TEWD shows the FP Control Relay as the same location as the "fuel pump relay". Are these just interchangeable names?

This is the FP relay that I tested (but it only has 4 connectors)
ry411-1.jpg


I was going to test the wiring from the fuel pump to the relay tomorrow but I guess if I'm messing with the wrong relay I'll wait. But at the same time, with the above pictured relay unplugged the fuse did not blow, so something is going on with it, or the wiring behind it, right???

Thanks so much for your patience and continued help, I'm so freaking weary and confused....
 
3p141592654

3p141592654

90T
Oct 11, 2005
3,816
16
38
Thousand Oaks, CA
Yes, that is the fuel pressure up (FPU) relay. The COR plugs into a relay board and looks quite different.

When you pull that relay you are breaking the fuel pump circuit. It is unlikely the relay is bad (do the checks I suggested, sorry about the 5 pin mixup, its 4 pins).

Most likely the circuit downstream of that relay is bad. Either the wiring is shorted somewhere, of the pump itself is shorted. I would try to power up the pump with the FPU relay removed (jumper pins 3 and 2 on the FPU relay body harness plug). If the fuse blows the problem is past the relay. Disconnect the pump at the tank and try again. Keep narrowing down the problem area.
 
3p141592654

3p141592654

90T
Oct 11, 2005
3,816
16
38
Thousand Oaks, CA
Could be, try jumpering pins FP and B+ at the diagnostics box and see if the fuse blows with the pump and FPU relay disconnected.

I still think the relay being bad is unlikely, but this could be that one time it is bad.
 
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