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car electrical system repair

malignity

Regular Member
Joined
Oct 9, 2008
Messages
1,101
Location
Warren, Michigan, USA
Does anyone know any place near Troy that works on vehicle electrical systems? I've taken my truck in three times to a repair shop near me and they can't fine tune the problem I'm having.

My truck (2001 Ford F-150 5.4L) is having some intermittent starting problems. I initially thought it was a bad fuel pump however now I'm doubting it after doing my research. For whatever reason, when my truck doesn't start, if I push down with moderate pressure on the fuel pump relay under the hood, or pull it out and put it back in, it starts fine, giving me heavy indication that the problem isn't my fuel pump in my gas tank.


I replaced the relay, cleaned the sockets with electronic cleaner, and even put dielectric grease on the prongs of the relay to really secure the connection. It still happens however, especially when there's a lot of moisture in the air.

Maybe someone can be of some help?
 

Bailenforcer

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Joined
Nov 3, 2009
Messages
1,077
Location
City
Sounds like the relay harness may have a loose connection. This is below the relay socket where the wires attach to the relay socket. If there is corrosion where the wires attach to that relay socket it can do exactly what you describe. Ford is know to have corrosion issues sadly.

Does anyone know any place near Troy that works on vehicle electrical systems? I've taken my truck in three times to a repair shop near me and they can't fine tune the problem I'm having.

My truck (2001 Ford F-150 5.4L) is having some intermittent starting problems. I initially thought it was a bad fuel pump however now I'm doubting it after doing my research. For whatever reason, when my truck doesn't start, if I push down with moderate pressure on the fuel pump relay under the hood, or pull it out and put it back in, it starts fine, giving me heavy indication that the problem isn't my fuel pump in my gas tank.


I replaced the relay, cleaned the sockets with electronic cleaner, and even put dielectric grease on the prongs of the relay to really secure the connection. It still happens however, especially when there's a lot of moisture in the air.

Maybe someone can be of some help?
 

Bailenforcer

Regular Member
Joined
Nov 3, 2009
Messages
1,077
Location
City
Looks like a common problem.

http://www.fordf150.net/forums/viewtopic.php?f=21&t=85258

The PCM relay (next to the fuel pump relay) must function in order for the f/p relay to function. Although these two relays appear to be the same, they are not, The PCM relay should be replaced w/ a PCM relay & F/P relay w/ F/P relay. It's not uncommon for them to fail, one very soon after the other.

also

http://www.f150online.com/forums/v8-engines/338705-99-f150-fuel-pump-relay-bad-suspect.html

this one below is really interesting there's a fuel pump inertia switch that I saw in several forums as a problem

http://www.ford-trucks.com/forums/922632-88-f150-4x2-ignition-issue-2.html




Does anyone know any place near Troy that works on vehicle electrical systems? I've taken my truck in three times to a repair shop near me and they can't fine tune the problem I'm having.

My truck (2001 Ford F-150 5.4L) is having some intermittent starting problems. I initially thought it was a bad fuel pump however now I'm doubting it after doing my research. For whatever reason, when my truck doesn't start, if I push down with moderate pressure on the fuel pump relay under the hood, or pull it out and put it back in, it starts fine, giving me heavy indication that the problem isn't my fuel pump in my gas tank.


I replaced the relay, cleaned the sockets with electronic cleaner, and even put dielectric grease on the prongs of the relay to really secure the connection. It still happens however, especially when there's a lot of moisture in the air.

Maybe someone can be of some help?
 

malignity

Regular Member
Joined
Oct 9, 2008
Messages
1,101
Location
Warren, Michigan, USA
So I took it in to an auto electric repair place...

It acted up twice; it got gave a code for Primary Fuel Pump Circuit Fault, however they couldn't figure out where it was. Every wire tested out perfect.

They replaced the PCM relay for free, and bypassed/rigged the inertia switch completely.

No charge because he said he didn't 'fix' anything. He said if that fixes it, it was an early Christmas present.

I was open carrying, and though normally most people don't notice or give reaction, I will say that his response was the best I've ever gotten.

"Holy fukc! You got a gun on your hip dude."

"Yep, open carry is legal in Michigan."

"Yeah man, I know, but I've never actually SEEN anyone do it. Do you ever get bothered?"

"Nope. Never; want a pamphlet?"

It turned out to be a good day after all. I even used Zig's 'royal flush' reference, and he really enjoyed that and seemed to understand the concept right away.
 

sprinklerguy28

Regular Member
Joined
Dec 9, 2009
Messages
666
Location
Michigan
Glad they got you up and running. I took my van in for wiring repairs a month ago. They said they fixed. I picked it up, drove 2 miles when smoke started coming through the dash and the van died. Opened the hood to find all the wiring was cooked. They refuse to fix it now saying it's not their fault. I'm waiting to see what the judge says.
 

malignity

Regular Member
Joined
Oct 9, 2008
Messages
1,101
Location
Warren, Michigan, USA
Glad they got you up and running. I took my van in for wiring repairs a month ago. They said they fixed. I picked it up, drove 2 miles when smoke started coming through the dash and the van died. Opened the hood to find all the wiring was cooked. They refuse to fix it now saying it's not their fault. I'm waiting to see what the judge says.

Oh hell man.. where did you take it? We live relatively close to each other, and there's not that many auto electric places in the area.
 

stainless1911

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Joined
Dec 19, 2009
Messages
8,855
Location
Davisburg, Michigan, United States
there is a time and place for everything. Computers belong on the desk, and in the radio, GPS, or radar detectors, not the engine.

pcthrow.gif
 

autosurgeon

Regular Member
Joined
Sep 29, 2008
Messages
3,831
Location
Lawrence, Michigan, United States
there is a time and place for everything. Computers belong on the desk, and in the radio, GPS, or radar detectors, not the engine.

pcthrow.gif


What are you talking about? Computer controlled cars are very reliable. Far more so than the old point ignition, carb heaps that came before.

How many of the pre computer cars got driven to 300,000 plus miles with no major problems?
 

stainless1911

Banned
Joined
Dec 19, 2009
Messages
8,855
Location
Davisburg, Michigan, United States
I really can't see a toyota corolla gracing the floors of barrett jackson 35 years from now. And the sound of a rice burner or even a BMW doesn't compare to the sound of a late 60's small block . Just pop the hood on a 68 camaro, and a 96 like mine, and tell me which one is easier to work on. I like my 96, but dang, its about impossible to work on, and way more expensive. Usually when something is wrong, its some sensor somewhere, not actually something wrong. If the sensor wasn't there, the car wouldn't have needed the repair to begin with.
 

Bailenforcer

Regular Member
Joined
Nov 3, 2009
Messages
1,077
Location
City
I hope it is finally fixed, and I am glad you have such a great OC experience added to that.


So I took it in to an auto electric repair place...

It acted up twice; it got gave a code for Primary Fuel Pump Circuit Fault, however they couldn't figure out where it was. Every wire tested out perfect.

They replaced the PCM relay for free, and bypassed/rigged the inertia switch completely.

No charge because he said he didn't 'fix' anything. He said if that fixes it, it was an early Christmas present.

I was open carrying, and though normally most people don't notice or give reaction, I will say that his response was the best I've ever gotten.

"Holy fukc! You got a gun on your hip dude."

"Yep, open carry is legal in Michigan."

"Yeah man, I know, but I've never actually SEEN anyone do it. Do you ever get bothered?"

"Nope. Never; want a pamphlet?"

It turned out to be a good day after all. I even used Zig's 'royal flush' reference, and he really enjoyed that and seemed to understand the concept right away.
 

autosurgeon

Regular Member
Joined
Sep 29, 2008
Messages
3,831
Location
Lawrence, Michigan, United States
I really can't see a toyota corolla gracing the floors of barrett jackson 35 years from now. And the sound of a rice burner or even a BMW doesn't compare to the sound of a late 60's small block . Just pop the hood on a 68 camaro, and a 96 like mine, and tell me which one is easier to work on. I like my 96, but dang, its about impossible to work on, and way more expensive. Usually when something is wrong, its some sensor somewhere, not actually something wrong. If the sensor wasn't there, the car wouldn't have needed the repair to begin with.


hmmm well to me the newer stuff is far easier to diagnose. But then it is what I do.
 

NRAMARINE

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Feb 16, 2010
Messages
523
Location
Anywhere but here.
For the record, bypassing the inertia switch is very dangerous. It is meant to cut off fuel in case of a collision. It is a simple spring loaded switch that is either released or engaged, that's it. The relay problem is totally unrelated to that switch. You should check the old relay for ants in it. Yes ants, they are attracted to the heat.. They will climb in there and cause all sorts of intermittent problems. You should definetely put the inertia switch back.
 

autosurgeon

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Lawrence, Michigan, United States
+1 on the inertia switch, they either work, or they don't.

Actually that is not really true as I have seen hundreds of intermittent over on IATN that were traced to the inertia switch works one day not another. Usually it is a sign that the magnet in the switch is getting weak or has cracked and is not holding the steel ball well enough.
 

NRAMARINE

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Feb 16, 2010
Messages
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Anywhere but here.
The inertia switch on this model isn't magnetic. It's spring loaded. The best way to test it is simple.

#1 bump the switch with your hand until you hear it go " boiiing"

#2 unplug and remove the switch ( you'll need a 1/4" socket and ratchet)

#3 using a multimeter measure the resistance in the switch. After it boings it should read open ckt. ( OL, ohms, high resistance

#4 press the red reset button until you feel it click into place. Retest the resistance, it should now read less than 5 ohms. If all of this checks, the switch is good.

I've been working on fords my entire life, I now work as a Ford Technician at a dealership and I have never seen an inertia switch have intermittent problems. It's either good or bad, and they very rarely if ever go out. Bottom line, it's a vital safety device designed to prevent firey death in case of a fuel leak in an impact. PUT IT BACK.
 

NRAMARINE

Regular Member
Joined
Feb 16, 2010
Messages
523
Location
Anywhere but here.
there is a time and place for everything. Computers belong on the desk, and in the radio, GPS, or radar detectors, not the engine.

pcthrow.gif

It is nice however to be able to plug the IDS laptop into it and monitor just about everything from which cylinders are hitting, evap system leaks, monitor fuel trim, and best of all freeze frame data. So when some punk kid with a new Mustang mommy and daddy paid for swears "Honestly, I was doing 70 on the freeway in 5th gear when the motor just seized up, that should be covered by the warranty" You print out this wonderful page from the PCM's memory that shows you speed, rpm's and what gear he was in. So when it sets a maximum speed reached code, and the rpm's read 8000, eeeerrrr. Wrong answer. Also, you can't hotwire a ford. If the tranciever doesn't recognize the chip in the key, the pcm won't give fuel, spark, or engage the starter. Technology is a pain in the ass, but if you understand it, it's not so bad.
 
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