2004 Ranger Fuel Pump Inertia Switch FPIS

[R.C. Champagne]

I have had intermittent crank no start issues with my 2004 Ranger 3.0 V6 XLT SuperCab with 100K miles. I am close to figuring out the whole problem. The other day the crank no start happened again and using my knowledge that I have been able to google I found the suspect major contributor. I am uploading photos showing what I found. During my trouble shooting this time, after getting the truck started, I happened to reach up under the dash to check the FPIS after the truck had been running for about 2 minutes and noticed the wires going to the switch were very hot. I'd guess at least 130 degrees F. I shut the truck off and dismounted the switch from the firewall, and the pics show what I found. This is a very serious fire hazard that any Ranger/Bronco II owner should be aware of. I have a good relationship with one of the local Ford service departments and plan to be working with them to go any further to resolve my issue. The intent of this posting is to get the word out about this condition and that any and all Ford vehicle owners of the mid 1990's to about 2011 should inspect this FPIS wiring and connector. For my 2004 Ranger this component is on the inside firewall just in front of the passenger's foot area under the dashboard. Likely in a different location on any ford of this era. I will add updates to this forum with my progress in resolving this issue.

 

[alwaysFlOoReD]

What does fpis stand for?

 

[R.C. Champagne]

What does fpis stand for?

Fuel Pump Inertia Switch. In some info I have come across it is referred to as just IPS.​

 

[pjtoledo]

toasted wires on that switch are very common.
since only the ends of the wires are toasted it's the connection that's getting hot
replacement pigtails are available. do the switch too.
the PCM monitors the voltage at the switch, if it doesn't like what it sees it shuts the power off to the fuel pump.

 

[R.C. Champagne]

It is not just the wires are toasted it's the whole connector and wires at the connector at the FPIS. Obviously, something that has developed over time. I like that the pigtail can be purchased and hopefully after that repair will fix the whole problem but my experience as an aircraft mechanic makes me think that there's more to the obvious repair. Why over time would this condition occur? Wires too thin - fuel pump motor too big and or something introducing resistance/impedance in the wiring causing the heat? I feel lucky, based on the condition of the wires and connector that my truck didn't catch fire! I do have other thoughts about ALL of that. My main concern is that it's not just toasted wires to me and can be replaced with parts - there's the why...

 

[sgtsandman]

As a guess, if there is a passenger s lot of the time, snow and water from rain being brought in could be the culprit.

I've been seeing s lot of corroded wires and connection issues on the Postal Service LLVs as of late. They do have a reputation of leaking at the seams near the rear corners. So, fhat is probably the cause for them.

For you, other sources could be a clogged A/C drain for the evaporator or a windshield leak, if passengers aren't a common thing for you. Another possibility, though remote, is that the door seal is leaking.

Corrosion in the connector could cause resistance, and thus heat. So, what the others are saying could be the issue. The intia switch isn't known to be a fire hazard. Old ones can be quirky and trip easily. Especially if the truck was ever in an accident and it tripped then. Once it's tripped once, they can trip from a hard door closing or a hard bump. So, there is that issue, but fire is not one that is generally something we've seen or has been an issue to look for and warn about.