Relays

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Shadow_D

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Ok so this is what Beast is doing now...

Took Beast out for a drive day before yesterday (first time Beast has been out since November) and all seemed ok. Battery was a little week from sitting but no big deal.

Yesterday I tried to start Beast so I could move it out of the way and the battery was dead. I thought I heard the fuel pumps run a couple of times but just didn't pay much attention to it (Key out of ignition).

So at this point I'm starting to pay attention to the noise it made. Shouldn't those pumps stay off till the key is on? I understand them keeping pressure up in the system but I didn't think they would do it with the key off and in my pocket.

Also I have had to replace those 2 relays under the hood several times over the last few years. Something is def going on here that I haven't been able to track down. As I'm sitting here typing, I'm starting to think something could be going on with my wiring. I have a primary wire coming from the battery to a post inside the truck, from there it is split, 1 goes to some of my electronics and the other goes to a relay that is active at the ignition (i.e. is live with the key on). Maybe it is as simple as that relay is bad or going bad and back feeding power to the "key ON" circuit huh.gif

I'll check that today...

Any other ideas besides that, that come to mind?

 
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miesk5

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yo!

Ck FP Relay and if good, ck EEC Relay; then possibly the IGN Switch; (Shadow, if Batty is discharged now, disc batty cables & charge batty fully; re-conn cables..listen for Fuel Pump. If it is running, ck IGN lock cyl /switch w/key and jiggle to see if Pump turns off)

Some info (substitute EEC for PCM...)

When the ignition switch is ON, it turns the EEC power relay ON. The EEC power relay provides power to the powertrain control module (PCM) and the control side of the fuel pump relay.

Power for the fuel pump(s) is supplied through a fuse link or high current fuse attached to the starter solenoid (battery side). From the fuse link or high current fuse, current flows through the fuel pump relay and inertia switch to the fuel pump(s).

The fuel pump relay is controlled by the PCM. When the ignition switch is turned ON, the fuel pump(s) will operate. If the ignition switch is not turned to the START position the PCM will shut the fuel pump(s) OFF after 1 second. The PCM will operate the fuel pump(s) operate the fuel pump(s) when the ignition switch is turn to START position to provide fuel while cranking. After the engine starts, the PCM will continue to operate the fuel pump(s) unless the engine stops (turn key Off or eng prob), drops below 120 rpm or the inertia switch is tripped.

 
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Shadow_D

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Update:

I've been out working on Beast today and disconnected "My" wiring and the relays are still going with the key out of the ign...

miesk5: I haven't checked your idea yet but I will work on that tomorrow.

Any other ideas besides what has already been said?

Thanks

Darrin

 
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Shadow_D

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Ok well I got a chance to work on Beast again yesterday. I played with the ignition and have still got the same problem... **** even with the key turned back to the acc position it still runs the fuel pumps...

Now I'm starting to get lost... Key off and out, key in and in Acc. and all my wiring disconnected pumps still running when I hook the battery up :???:

 
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Shadow_D

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Ok if that relay is bad *AGAIN* what would cause it to short out? I just replaced it last year...

 
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Shadow_D

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Ok well this would be the 6 time in 4 years give or take... This tells me that there is something else going on here. Maybe something it going on with my wiring that is causing it. I have my stuff disconnected at the moment but I have tied into the battery going into 2 breakers. 1 breaker has a feed that goes to a relay that gets it's switching power from the ignition switch and the other one goes to some of my "accessories".

At this point I think I'll just go back and start to test all of my stuff to see if something is crossed.

Something else I just remembered, this winter after clearing the snow off Beast and running it for a little while trying to melt ice, I noticed ice in the area of the fuse block. Maybe something is crossed behind or in the block causing a weak short that is causing the relays to think the key is on. I guess I'll have to pull the fuse block and check for rust...

 

BroncoJoe19

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If you test the relay, and it remains closed even after you remove power to it, then perhaps there is so much power going through it that the contacts weld shut. I guess some kind of a short but not enough to blow the fuse. Could the fuse be over rated? My books states it should be a 20 amp **** fuse.

If a 20 amp fuse blows, then I'd be right about the excessive draw. If not, I might still be right, but just didn't prove it.

 
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Shadow_D

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I'll have to go out and check to see... That goes back to the ice build up, maybe there is some rust back there that is causing the power to bypass the fuse. Next is where is that short going to be???

The hard part is I have so much time and money invested in this thing that every time I start to think I should give up and sell it I just think I'll never get anything back :( /emoticons/[email protected] 2x" width="20" height="20" />

 

BroncoJoe19

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Yeah... when you see other members buy their's, so often, for so little; one can't expect to get for a bronco, what we know they are really worth.

 
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Shadow_D

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Ok here is the deal...

I have pulled those 2 relay's out and tested them here on the desk.

Relay 1)

413182

336

5 pin

Pins 1 and 2 are for power and has an internal polarity diode so pin 1 is hot and pin 2 is ground

Pin 3 is the "common" pin

Pin 4 according to the diagram on the relay is normally open

Pin 5 according to the diagram on the relay is normally connected to pin 3

Now when I check the relay pins 3 and 4 are connected and pin 5 is open

When I connect power to pins 1 and 2 I hear the relay actuate.

Relay 2)

413157

257

5 Pin

This relay is exactly the same as above except pins 1 and 2 do NOT have the polarity diode and will allow activating regardless of polarity.

At this point I would say both relays are working correctly and that this is not the problem...

I have no idea anymore as to what the problem is at this point. If I had hair I'd be pulling it out right now.

 

BroncoJoe19

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Darren,

As Miesk5 said, (in other words): The ignition switch powers the PCM relay, which powers the Fuel pump relay. IF the relays are good, then the next most likely candidate is a bad ignition switch. Maybe it needs an adjustment. I know that Seabronc posted an howto on adjusting it.

If you think that the feed to your electronics stuff may be backfeeding power, try cutting them out of the circuit for a test.

 
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Shadow_D

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I already cut them out of the circuit and still have the same results...

Looks like I need to get under the dash and look at that ign switch...

 

BroncoJoe19

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Looks like I need to get under the dash and look at that ign switch...

You know that either we have, or miesk5 has one at www.broncolinks.com , a link to a howto get access to the switch, with nice pictures.

 
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Shadow_D

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I have the switch in my hand right now...

Looking inside (from what I can see of it) it doesn't look burnt or anything... it actually still looks new...

Is there a way to test the switch out of the truck? Should I just get a new switch???

Sorry, I've been stressed to the max lately and and my brain just isn't what it used to be lately... I'm just trying to fix just one of many problems going on in my life.

 

BroncoJoe19

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Darren,

Do you have a Haynes manual? It has a pinout for the switch, and what should be continuent (is that a word) with what.

If your switch LOOKS good, and is moving smoothely I am guessing that it is good. Unless you see a reaso nwhy one may be shorting to another pin, then it may be more of an adjustment issue... where the rod still keeps it ON when it should be off.

I think that the checks that are offered by Haynes are to make sure that it is making contact where and when it should... your problem is that it is making contact when it should NOT.

 

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