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relay keeps going bad

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Old 05-15-2017, 02:22 PM
pete98cobra pete98cobra is offline
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relay keeps going bad

Need some help. The relay for the fuel pump keeps going bad. Is this a sign my fuel pump is going ? I just replaced my 2nd relay ( lasted about 1 week ) 1st lasted 16 years
Or is there another issue to look at ?
Any help much appreciated
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Old 05-15-2017, 03:01 PM
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Hussler Hussler is online now
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I would think the fuse would go first if it was the pump. Was the replaced relay a good quality Ford part or some cheap off the shelf one?
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Old 05-15-2017, 05:43 PM
pete98cobra pete98cobra is offline
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It was replaced with a ford . Same part number matching relay. They look identical
I found a 3 pack of new Ford relays on ebay . Basically $20 for the three. Local stealership wanted $15 a piece
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Old 06-19-2017, 02:49 AM
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where is the fuel pumpp relay located
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Old 06-19-2017, 06:29 AM
pete98cobra pete98cobra is offline
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where is the fuel pumpp relay located
under the hood. rear corner. Near the master cylinder
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Old 06-19-2017, 08:30 AM
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Are you sure you are changing the fuel pump relay? On my 2001 F250, it was located behind the radio. Sounds like you are changing the PCM relay, which also triggers the fuel pump relay through the PCM controls.



Fuel pump relay location
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Old 06-19-2017, 10:54 AM
pete98cobra pete98cobra is offline
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Originally Posted by mueckster View Post
Are you sure you are changing the fuel pump relay? On my 2001 F250, it was located behind the radio. Sounds like you are changing the PCM relay, which also triggers the fuel pump relay through the PCM controls.



Fuel pump relay location
yup . My bad . It was the PCM relay. I swapped them around after I checked all the fuses. And the fuel pump started working again
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Old 06-19-2017, 11:19 AM
pete98cobra pete98cobra is offline
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Would old age make the PCM relay go bad ?
One thing I did notice on the relays I bought on Ebay. They did have the ford part number on them , but did not have the ford logo. When I replaced the PCM relay . I went ahead and replaced all 3 . A week later the PCM relay went . I still had a original relay that I had swapped for one of the newer ones ( eBay) in my garage. A few days later my blower motor quits . I decided to go to Ford and buy 3 new relays , and replaced all 3 with factory relays. That was a week ago. I kept a original and the eBay relay in my truck for a spare.
I'm hoping it was just an old relay going bad. Florida sun is brutal on equipment.
If not old age , and there is something wrong. What would cause the relay to go bad ? I have the auto enginuity scan program on my laptop. Couldn't see anything wrong, or I could be missing something.
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Old 06-22-2017, 12:29 PM
retiredsparky retiredsparky is offline
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Bad voltage regulator will cause max output from alternator-can burn out relay coils. Fuel pump bearings or windings starting to fail. Can cause higher current draw which could damage relay contacts, but not blow fuse. You could use a multimeter to read how much current the pump is drawing.
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Old 06-22-2017, 10:10 PM
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You may try taking contact cleaner and cleaning connections where relay plugs in really well. Under the hood all those years could cause corrosion down in the connection

Are you sure they are actually bad? You could take a meter and measure resistance across 86 and 85 and also 30 and 87a. You would have to power and ground 85 & 86 to check resistance across 30 & 87. IF it reads across all those, its not the relay. 85 & 86 should have some resistance as that is the coil. The others should read essentially the same as touching the leads together.
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Old 06-23-2017, 03:43 AM
pete98cobra pete98cobra is offline
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Originally Posted by retiredsparky View Post
Bad voltage regulator will cause max output from alternator-can burn out relay coils. Fuel pump bearings or windings starting to fail. Can cause higher current draw which could damage relay contacts, but not blow fuse. You could use a multimeter to read how much current the pump is drawing.
I will check it out this weekend. If the weather holds out
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Old 06-23-2017, 03:49 AM
pete98cobra pete98cobra is offline
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Originally Posted by retiredsparky View Post
Bad voltage regulator will cause max output from alternator-can burn out relay coils. Fuel pump bearings or windings starting to fail. Can cause higher current draw which could damage relay contacts, but not blow fuse. You could use a multimeter to read how much current the pump is drawing.
Quote:
Originally Posted by carltonwebb View Post
You may try taking contact cleaner and cleaning connections where relay plugs in really well. Under the hood all those years could cause corrosion down in the connection

Are you sure they are actually bad? You could take a meter and measure resistance across 86 and 85 and also 30 and 87a. You would have to power and ground 85 & 86 to check resistance across 30 & 87. IF it reads across all those, its not the relay. 85 & 86 should have some resistance as that is the coil. The others should read essentially the same as touching the leads together.
I didnt see any corrosion on ends relays or down where they go in. I did pop the cover off 1 of the ebay relays I bought. It was blown. I havent done the factory relay yet. I was going to compare the 2 to see quality difference. . Luckily my truck for its age has if any very little corrosion on it. Some folks cant believe its almost 17 years old . I try my best to take care of it.
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