Hello everyone, I am having trouble solving a problem with my inertia switch. It was tripping at various time with no rhyme or reason. I removed it and noticed some water had been reaching it from an open hole above it in the firewall. I took it off and took it apart. I didnt see any corrosion so I cleaned it and put it back together. One of the wires on the pigtail (pink w/ black tracer) was dark and had distorted the connector a little. When I started the truck the wire got hot. I cut it back about 12 inches and pulled off the coating. The copper inside was dark from overheating. I spliced in a new piece of wire and reconnected everything. The wire is still getting warm now but not nearly as hot as it was. According to all the diagrams I can find this wire is supposed to go to the tank selector switch, but mine runs up into the dash to hidden places unknown. The inertia switch has only tripped once since the repair and I have also done some wheeling since then with no issues. Does anyone else's wire get warm when the trucks running? Any Ideas would be helpful.

 

Sounds like someone has tied both fuel pump power wires together and bypassed the selector switch.

 

recently they were both working properly and switching from front to rear. We havent touched any wiring since then, with the exception of replacing the fuel pumps and plugging them back in. During that time I cleaned the connectors out and used dielectric grease. Do you think a ground issue could be causing the problem?

 

They both use the same ground wire and it is grounded at the drivers side radiator support.

 

That same wire and inertia switch connector were melted on my truck too. I re-wired also, bypassing the inertia switch temporarily until I can do something more permanent. Other than the changes I made, it is all stock factory wiring.

 

Thats the first time I have heard of this happening. I'm interested to find out why?

 

If you read his other post he says that both high pressure fuel pumps in both fuel tanks run at the same time.
This would mean that the inertia switch connectors and the inertia switch contacts are carrying twice as much current as they were meant to carry.
Also he said the selector switch has no effect on fuel tank selection and that he replaced the switch.

 

I will be working on this again today...after I figure out what happened to my ignition yesterday! Now the front pump wont run at all...so Im starting to suspect worn wiring or a bad ground as mentioned earlier....Ill keep you posted

 

Didnt get to work on this today, I will be hitting it tomorrow. I did notice that a wire on the harness for the switch was backing out so I secured it, maybe that will fix the problem. I let you know

 

on my truck, the inertia switch is good, the fuel keeps cutting off because the 30 amp maxi fuse for the pcm power keeps blowing after 30 mins or so of driving...