Urgent fuel pump still runs after car is off

[packardbell]

Wow... that's a short waiting to happen... time for a new pig tail.

repaired and used many heat shrink tubes around the repaired wires now. should be good to go.

[carbon]

Wow... that's a short waiting to happen... time for a new pig tail.

[packardbell]

teflon taped the coolant sensor, i removed it to get better angle/leverage to remove the oil switch.

burnt wires



coolant temp wires melted

[pocket-rocket]

When it rains, it pours.

Last week I went to change the fuel pump in my wife's AWD Mountaineer. That turned into a tank as well due to the fuel fill nipple busting off of the tank when I went to remove the hose. Then a fuel tank pressure sensor when the old one wouldn't come out of the old tank, then other things I had intended on fixing on it. Figured I would get it done on my week off of work for the 4th.... $1k later the truck does run really nice and it's quiet again.

[packardbell]

Despite it being mentioned I forgot about that switch mainly because GM went to the 3 pin one so mine doesn't have it, lol.

also noticed that the insulation from the wires was melted, so looks like new wire and connector for oil pressure and coolant temperature.

[pocket-rocket]

Despite it being mentioned I forgot about that switch mainly because GM went to the 3 pin one so mine doesn't have it, lol.

[packardbell]

the connector cavity being filled with oil isn't surprising.... the 3-pin versions seem to fail the same way as well.

[robertisaar]

the connector cavity being filled with oil isn't surprising.... the 3-pin versions seem to fail the same way as well.

[packardbell]

Alright guys i located the other 2 pin oil pressure switch, not easy to get at and had to break off the plastic part to remove it. the plug was full of oil and yup this is the switch that is causing the fuel pump to stay on.

[1988GTU]

1 terminal STANDARD MOTOR PRODUCTS Part # PS222 2 terminal STANDARD MOTOR PRODUCTS Part # PS216
Also, you should have a main f/p relay and a secondary f/p relay (STANDARD MOTOR PRODUCTS Part # RY121). The 2nd one could be internally failed.

Did someone install an Inertia Switch? Check for one and see if its shorting out.

[packardbell]

I'm willing to bet your short isn't on top of the tank considering pulling the relay doesn't do anything. I would pull the housing for the relay and fuse and flip it over. I mean, the fuse supplies power to the relay and the only way to kill the pump is to pull the fuse. This tells me that the relay is just there for looks right now, but since the fuse has power, everything going up to it should be good.

Tonight after work i will try to locate that two terminal oil pressure switch, unplug it and see if the fuel pump runs or stops. If the pump stops then we have found the problem being the second two terminal oil pressure switch. If the pump continues to run then i will flip the housing for the relay and fuse and see what is happening there.

[pocket-rocket]

yes you are correct, i would like to know which of the wires in the back is giving a constant +12V. Like the other member said there is two or maybe more wires on top of the fuel tank that is shorting a +12V making the fuel pump run all the time.

I'm willing to bet your short isn't on top of the tank considering pulling the relay doesn't do anything. I would pull the housing for the relay and fuse and flip it over. I mean, the fuse supplies power to the relay and the only way to kill the pump is to pull the fuse. This tells me that the relay is just there for looks right now, but since the fuse has power, everything going up to it should be good.

[packardbell]

curious...... looks like most 87 and 88 60V6 applications used that 1-wire switch/sensor? i wasn't aware anything other than the 3-wire setup was used.

i imagine you will find that oddball sensor on top of the bellhousing.

i googled and search high and low to figure out what is wrong with my fuel pump not shutting off. Stumbled across a few threads and posts about the oil pressure switch beside the oil filter being a 3 terminal switch. Looked at mines and found a 1 terminal switch, like WTF? Atleast i know i am not insane and those years came with two switches instead of one. You learn something new everyday.

[robertisaar]

curious...... looks like most 87 and 88 60V6 applications used that 1-wire switch/sensor? i wasn't aware anything other than the 3-wire setup was used.

i imagine you will find that oddball sensor on top of the bellhousing.

[packardbell]

other than that second line drawing, no.

okay thanks, anyways i will probe around on top of the bell housing area and see if I can find anything there.
so there is a second oil pressure which i assume is two terminal which controls the +12V to the pump. I was searching on rockauto for that part but i found 1 and 3 terminal ones.

ok i found the two terminal switch on rockauto.