Main IndexAuto Repair Home Search Posts SEARCH
POSTS
Who's Online WHO'S
ONLINE
Log in LOG
IN









Search Auto Parts

1994 f-150 4.9L duel tank no voltage at inertia switch


First page Previous page 1 2 Next page Last page  View All Email This Post



hoytray
User

Aug 31, 2016, 10:51 AM

Post #1 of 42 (1896 views)
1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

1994 f-150 4.9L duel tank 4x4 250,000miles. Hello, I am Hoyt. My truck showed check engine light for a few weeks off and on but was never able to test to see the code; sorry! Rear pump has never pumped but does display fuel level; Front pump pumps and sometimes tells the truth on fuel level. I was thinking it was front fuel pump going out, because it would get sluggish with a loss of pickup power as I was accelerating at times; but, mostly ran like normal. Then as driving almost ten miles from home, the top radiator hose blew, and at same time truck died. On shoulder I changed hose as I had one behind seat. No start. Towed home. Test went like this. (tell me if I am leaving anything out) first I bought the two pumps because was thinking it would be nice to have two tanks working. Found reason for front fuel level not working (float has damage). Rear tank ring is rusted so need to order parts. After replacing front pump- still no pumping- checked for voltage with Key on and Key cranking using a voltage meter- 0volts. I decided to Start over. Only recently found this Forum (thank God) so this is what I have done. Did research on wiring schematic. Started with the relay as the fusible links seems ok- no visible damage. Schematic shows Yellow wire hot all the time- it is. 20amp fuse is good. Tested relay- ohm meter check was done like this, pin30to87 ohmed, 85to86 ohmed, next a 12volt jumper wire 30to87 & relay clicks. Next tested relay socket, battery connected, with volt meter- probed with red cord to pin1-Yellow & black cord to pin2-Green wire = 12volts. Red @ pin1, black @ pin3-red wire = 12volts. Red@ pin1, black@ pin4-blue/orange strip wire= 7volts. I used a jumper wire from Yellow to Green at wires under socket and at top of socket, both kicked on fuel pump. Schematic shows Green wire goes to Inertia switch. Jumper on Green wire to Yellow wire to see if power is at Inertia= No. Wire color at my Inertia is Green/yellow & Red/yellow. This I believe tells me because I read lots of post that I have an open between the socket and the inertia; but no clue was given on how to fix that. If that is the problem, I still would like some instructions on what to do from here. Another post mentioned if pump only buzz's when jumped in must be computer; so I did look/smell/test- seems ok! The best I can tell is a ground problem. I need some experienced help here. I can only do the trouble shooting tips if they explain them better and Chilton & Haynes are terrible for someone like me. help!


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Aug 31, 2016, 11:08 AM

Post #2 of 42 (1892 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

Just a WAG and somewhat common for the vintage - Ford's relays.


Just try using relay for A/C in fuel pump spot and back then see if A/C will click with key on run, A/C set to work. Sounds nuts and is but dang relays just test OK and don't work - split seconds and work again it you whack them, touch them or just not enough amps to really make the full connection.


OE from Ford are dirt cheap! Buy two if like $5 bucks.


Yes - an inertial switch cuts off fuel pump being used. It would just test light work on one side not on other if tripped but one side stay light - test light enough.


Grounds to tank and think fuel necks. Test those backwards but that's the return and you've seen now power at pumps I think - right?


Relays - most common. Can blow two at once and the one marked EEC at the same time you won't get fuel,


T
Said WAG - not harm in trying.........



Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Aug 31, 2016, 3:45 PM

Post #3 of 42 (1881 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

There is a connector under the hood that looks like this:




If you take a jumper wire and attach one end to the battery negative and touch the other end to the light blue orange wires at the terminal in the connector, does the pump come on? The fuel pump relay should also click when you ground those wires in connector. The ignition has to be turned on.







Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Aug 31, 2016, 3:49 PM)


hoytray
User

Aug 31, 2016, 4:18 PM

Post #4 of 42 (1874 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

I am not sure if a/c meant air conditioner, but, I did try a few other relays.
Tried & It is not the answer.
My truck has no air conditioner, just so ya know.
Test light not lighting on Inertia switch either wire. How are you saying to test Grounds to tank and fuel necks? I need details here.
No power at tank unless I hot wire 30&87.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Aug 31, 2016, 4:31 PM

Post #5 of 42 (1871 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

Do you even realize that it only powers for 2 seconds when the key is first turned on and then shuts off?



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Aug 31, 2016, 4:37 PM

Post #6 of 42 (1869 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

You know this is odd:


Quote
the top radiator hose blew, and at same time truck died.



Why would a radiator hose blowing out cause the engine to shut off? Why would something like that affect the fuel pump circuit?





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.


hoytray
User

Aug 31, 2016, 4:55 PM

Post #7 of 42 (1866 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

I will do this tomorrow on the dlc


(This post was edited by hoytray on Aug 31, 2016, 4:56 PM)


hoytray
User

Aug 31, 2016, 5:00 PM

Post #8 of 42 (1861 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In


In Reply To
Do you even realize that it only powers for 2 seconds when the key is first turned on and then shuts off?

That is what I understood from reading post. What are you getting at? Maybe you think I didn't have the tester on the wire when I was cranking; if that's it then yes I did have a helper. Otherwise what are you asking? I only learn from doing and reading. Thanks


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Aug 31, 2016, 5:05 PM

Post #9 of 42 (1858 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

Answer this, Does it have spark?



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



hoytray
User

Aug 31, 2016, 5:05 PM

Post #10 of 42 (1857 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In


In Reply To
You know this is odd:


Quote
the top radiator hose blew, and at same time truck died.



Why would a radiator hose blowing out cause the engine to shut off? Why would something like that affect the fuel pump circuit?


Odd yes!! I believe that it just happened at same time for the fun of it, ya know Murphy's Law and all. But I looked and nothing was damaged other than the hose had a hole. Weird


hoytray
User

Aug 31, 2016, 5:09 PM

Post #11 of 42 (1855 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

does what have spark? the spark plugs. I will check that and tell you but I don't see how that will affect the things I am asking about in the OP. Will have to do that in the day light tomorrow because raining now


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Aug 31, 2016, 5:13 PM

Post #12 of 42 (1851 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

Yes, the ignition system. Is there spark to the plugs?

Believe me, it does matter.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Aug 31, 2016, 5:14 PM

Post #13 of 42 (1850 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

Which hose blow out? Did coolant spray all over the engine?

HT is right the fuel pump should come on for a few seconds when you first turn the ignition on. Does it do that? Another thing to consider is that when you are starting the engine, the engine computer is expecting to see a PIP signal from the ignition control module. If the engine computer doesn't get that signal while your cranking the engine, you won't see power to the fuel pump. The hose blowing and the fuel pump not working might be related somehow if coolant sprayed all over everything.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Aug 31, 2016, 5:14 PM)


hoytray
User

Sep 1, 2016, 3:12 PM

Post #14 of 42 (1829 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

did this test Discretesignals on the dlc and fuel relay did click and fuel pump kicks on. Soon as I get a helper I will check truck for spark at distributor. Ok had a 16 gage wire hooked to neg battery post to a spark tester and to the distributor #1. no spark am gonna go back outside and check with jumper cables this time to see if the 16g wire was too small. Okay. so had jumper cable hooked up to neg battery post & top of spark tester at the distributor hooked to #1. NO spark. so I will in the morning unless you say otherwise start a no spark test and see whats up there. I still don't know how to do the ground testing if someone can detail that to me. that would be great
thanks in advance. I will drive my truck this weekend with your all's help


(This post was edited by hoytray on Sep 1, 2016, 3:41 PM)


Discretesignals
Ultimate Carjunky / Moderator
Discretesignals profile image

Sep 1, 2016, 3:58 PM

Post #15 of 42 (1822 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

There is a connector or plug called a SPOUT. It should be near the ignition control module. Remove the plug and then see if you have spark.



Obviously the pump ground is good because you were able to get the pump running by grounding the test terminal in the connector. That tells you a lot of things. You have power from the EEC relay, the fuel pump relay is good, and you have a good working fuel pump circuit and pump.





Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.

(This post was edited by Discretesignals on Sep 1, 2016, 4:00 PM)


hoytray
User

Sep 1, 2016, 6:02 PM

Post #16 of 42 (1814 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

will do. I have a helper tomorrow.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Sep 2, 2016, 3:37 AM

Post #17 of 42 (1807 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

You need a more accurate way to test for spark.

You can buy one of these for a couple dollars.





~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



hoytray
User

Sep 2, 2016, 5:04 AM

Post #18 of 42 (1804 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In


In Reply To
You need a more accurate way to test for spark.

You can buy one of these for a couple dollars.



This is the exact one I have and used. Tell me how to use it. I thought I was doing it like it said to do.


Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Sep 2, 2016, 5:39 AM

Post #19 of 42 (1802 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

That one, one end goes into a spark plug boot the other with clamp to ground metal. You watch for spark thru that glass area dialing the gap. Start close and widen gap to see how far spark can jump or if never any problem is before that or not hooked up properly,


T



Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Sep 2, 2016, 6:00 AM

Post #20 of 42 (1799 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

It should be able to jump about a 1/2" gap.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



hoytray
User

Sep 2, 2016, 6:09 AM

Post #21 of 42 (1795 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

ok. soon as I can which will be this morning before noon I can do that. I appreciate the help. I can follow instructions but really need details sometimes since I am novice here in this field. I love working on my truck; but cant stand when I have to because the other two are down and I have no back up vehicle. so thankyou guys


hoytray
User

Sep 2, 2016, 3:12 PM

Post #22 of 42 (1780 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

hooked in the end of spark plug wire One and no spark.


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Sep 2, 2016, 3:22 PM

Post #23 of 42 (1777 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

OK, now find out if the pump is giving you the 2 second prime when the key is first turned on.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



hoytray
User

Sep 2, 2016, 3:30 PM

Post #24 of 42 (1774 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

ok now put up with me please. How do I do that?


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Sep 2, 2016, 3:33 PM

Post #25 of 42 (1772 views)
Re: 1994 f-150 4.9L duel tank no voltage at inertia switch Sign In

It's not complicated. See if the fuel pump runs for 2 seconds when the key is turned on.

Stick your ear in the filler pipe while a helper turns the key on, whatever. How have you been telling if the pump runs up till now?



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.







First page Previous page 1 2 Next page Last page  View All Email This Post
 
 


Feed Button




Search for (options) Privacy Sitemap