[Cdugan01]

My wife's 03 zx3 is blowing the #9 20amp fuse in the under hood fuse box, main engine fuse...
only does it when it shifts to reverse, and seems to only do it when its warm(been running for a while)

I checked all the wiring i could find in the engine bay, figuring something was shorting out , but can't find any evidence of that.

The only thing i can find that doesn't seem right is that the passenger side top radiator mount is letting the radiator and fan get way too close to the heat shield...(see attached pics)

if anyone has any ideas please tell me, or if that radiator getting that close could cause it, i need to get it somehow to stay in one place..

thanks in advance
Chad

 

[freemind]

That engine ground on the engine hook next to the power steering is totally inadequate. Is it connected to the strut tower as well? Can you take a pic at that point please?

Also, it looks like your upstream o2 sensor wire(s)might be rubbing/shorting on the heatshield.

 

[Cdugan01]

the ground is still perfect on the strut tower underneath the power steering reservoir ... the end u see in the picture wasn't hooked up at all till about a week ago, i saw it and did what i could.

i need to figure out a way to pull that front passenger side radiator mount back in where in belongs, because its causing the o2 wire to be touching heat shield

 

[freemind]

Go to the parts store and buy a ring terminal and put it on that wire. Take a wire wheel or sandpaper and sand the mounting point down to bare metal. Do the same to the bolt. Reattach.

You should be able to use some zipties to hold the o2 wire to the coolant hose for the interim.

 

[freemind]

I am moving this to General Tech Chat for better exposure.

 

[BC_ZX3]

only does it when it shifts to reverse, and seems to only do it when its warm(been running for a while)

Transmission range sensor wiring possibly since that's on that fused circuit. And it is a dead short somewhere (power direct to ground). You need to get under the car to examine that part of the wiring harness. Front of the transmission towards driver's side.

O2 sensor has its own fuse (#18) so I don't think that's related although you should follow freemind's advice and get it secured away from the heat shield or it will cause a new set of problems in the future.

 

[Cdugan01]

Did all that Freemind said and its working for now... seems to work just fine when engine hasn't been run much... but after 20-30i minutes of the car running it will kill the fuse as soon as it shifts to reverse

 

[BC_ZX3]

Shifting into reverse is the key. Check anything associated with that; range sensor, reverse lights, etc.
Heat (from running) can cause nearby metal to expand slightly or wiring to sag and trigger a short intermittently.

 

[Cdugan01]

Was under the car for a while today but couldn't find anything loose or any stripped wires... when i get home from work tomorrow i'll hafta do some more searching ...was also told it could b the reverse switch on top of transmission under the motor mount.

 

[sailor]

More likely the harness moving and a bare wire shorting out when shifted into reverse.

 

[Cdugan01]

Still haven't been able to find anything wrong, but have some more info. If the car hasn't been running in 2-3 hours , it will go into reverse just fine and not blow the fuse. However, if I drive the car 3 miles to the store and then go to back up the fuse will blow everytime, very confusing?!?