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F-150 Relays

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=22809
Printed Date: May 14, 2024 at 8:11 PM


Topic: F-150 Relays

Posted By: Haldol
Subject: F-150 Relays
Date Posted: December 13, 2003 at 6:42 PM

okay in the under-hood power distribution box on a 1997 (or 98 or 99) F-150, there are several mini fuses, maxi fuses, and 2 sizes of relays. the particular truck that i am working on has 3 small relays and 3 big relays. the small ones are the ones i have questions on. there is a diagram that i so wish i had a picture of on the side that does not label which pin is which and the pin configuration is not conventional. i am trying to find out which pin is which.

basically, if i can draw this out, you have two pins on one side of the relay running vertically like this:     |  |   and then on the other end of the relay you have 3 pins running horizontal like this: __ well i cant type 3 lines on top of the other but picture it if you will... i cant really draw it im sorry

anyway im trying to find out of the five pins (2 vertical on one side, 3 horizontal on the other side), which pins are pins 30, 85, 86, 87, and 87a.

any suggestions?




Replies:

Posted By: mikeshonda750
Date Posted: December 13, 2003 at 7:33 PM

If i was at work i could find out exactly what they are for.

Im wondering though, what are you trying to attempt? If your trying to tie into the relay, why not simply use a new relay and wire it up and mount it somewhere else? Another thing is, it may not even be a normal relay, could be double switching or have weird outputs ext... whatcha tryin to do friend?



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Posted By: Teken
Date Posted: December 14, 2003 at 12:31 AM
The simplest way to do it is as follows.

1. Set your DMM to measure resistance. Measure the two pins that are vertical, to varify they are the coil.

If it is, it will result in a resistive value from aprox. 80-130 ohms.

2. Take your negative (black) DMM lead and secure it to one of the three terminal pins. This will give you a reference.

Set your meter for continuity. If you do not have a diode / contintuity check. Then, simply set it to the lowest range in resistance on the DMM.

You will probe the other two horizontal pins one at a time. The one that makes the DMM beep or shows 0 ohms is the 87a or the common 30 terminal.

The other one will be of course, be the terminal 87.

Regards

EVIL Teken . . .




Posted By: Haldol
Date Posted: December 14, 2003 at 7:54 AM

what i am doing: my friend has the truck and it has a wierd intermittent wiper problem. the wipers just come on for no reason no matter if the switch is messed with or not. even if the truck is not running! i traced the wires from the switch to what ford calls the generic electronic module and then out of the module, through the firewall, to the power distribution box. the thing of it is, is that when i go to the wiper motor and measure voltage with the switch on high and low, i get 5v and 4v, which apparently is not enough to run the motor since the motor will not come on. when i connect 12v to the motor, it runs fine. the motor is not at fault. something between the switch and the motor is and the only thing that comes to mind is the relay. the truck had been wrecked on the front left side in the past before my friend got it. the power box under the hood is broken and it could be possible that the relay has a crack in it or some problem.

what does have to do with the pins on the relay? well if i can find out which pin is which, i can connect a conventional relay to it and run with it.

i will try what Teken suggested but id like a more definately answer as well, if anyone else could gather one.

thanks for reading

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Posted By: Teken
Date Posted: December 14, 2003 at 5:26 PM
Alright the following is what you needed to know. Please varify this information with your DMM to ensure the proper pin out of each connector on the mini 5 pin relay.


Starting by holding the relay vertically, so that the two horizontal pins are at the top. As you hold this relay the other three vertical pins will be at the bottom in your hand, when looking at it from the front.

The (1st) top horizotnal plug is, pin 3 which is number 30 common.

The (2nd) lower horizontal plug is, pin 5 which is number 87.

Starting from left to right of the vertical plugs.

| <- is pin 2 or the coil. | <- is pin 4 or 87a | <- is pin 1 or or the other coil end



=======================================================


___ <-- 30 common

___ <-- 87 NO


| <-85 coil   | <-87a NC | <-86 coil



Regards

EVIL Teken . . .






Posted By: Haldol
Date Posted: December 14, 2003 at 8:29 PM
f-ing awesome Teken! thanks a million! btw and off the topic completely: if i found a problem with this site's application guide for speakers, who would i make a comment too? i was looking at the speaker size on this site for a 1999 Buick LeSabre.. this site says 5 1/4 in the front doors. its actually an oversize   6 1/2 in the doors. any suggestions?

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Posted By: Teken
Date Posted: December 14, 2003 at 9:55 PM
You would direct your information to the Admin, who is so named, the12volt.

Best of luck in finding your gremlins, and if I can help out more let me know.

Regards

EVIL Teken . . .




Posted By: Steve #1
Date Posted: December 20, 2003 at 2:12 AM
The "ghost wipers" are caused by a faulty Muli-Function (turn signal) switch. Ford TSB# BC3279970207.
Replacing the switch should fix it. Tilting the steering wheel up or down a notch may help.




Posted By: Haldol
Date Posted: December 20, 2003 at 8:39 AM
We've already changed that. any other ideas though?

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Posted By: Teken
Date Posted: December 20, 2003 at 11:54 AM
You havent told us what the outcome has been, with regards to the relay check / replacement?




Posted By: Steve #1
Date Posted: December 20, 2003 at 11:19 PM
Most of the time it is the Multi-Function switch that is the culprit. Since that didn't fix it my second guess would be the wiring in the column or the GEM. When the GEM is at fault you normally have other electrical gremlins too, but it's one more thing to consider.




Posted By: Haldol
Date Posted: December 21, 2003 at 7:12 PM

well Teken, taking what you've told me, I went Saturday and worked on it again. There are two relays involved: one does the Park/Run and the other does the High Low. Low speed went to 87a, high went to 87; a jumper wire went from 30 of one relay to 30 of another. the switched 12v went to 86 on the same relay as the low and high wires and there was a wire coming from the multiswitch that went to ground when the switch was on that went to 85 on the same relay.

As I said, a jumper went from pin 30 of that relay to pin 30 of the other relay (the park/run relay). On the 2nd relay, pin 86 had switch 12 v, pin 85 had ground, and pin 87a had the wiper-park wire (causes the wipers to sit in place when you turn them off). My understanding of relays is limited. I get the first one but i dont understand the second one's wiring and how the jumper fits into place.



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Posted By: Haldol
Date Posted: December 21, 2003 at 7:16 PM

Btw Steve#1, so far we have inspected the wiring from the switch to the GEM and from the GEM to the distribution block. There are no other electrical problems in the vehicle so I don't think the GEM is the problem. The truck was wrecked before and rebuilt but the Power Distribution Block was not replaced. Consequently from the wreck, it was severly smashed. I believe that has something to do with it. On the above reply that I wrote to Teken, one thing I failed to mention is that I used a standard relay in place of relay #1 (the high/low relay) and b/c I mysteriously lost my other standard relay, I had to use the mini-relay for the second relay (the park/run relay).

Hope that's clear...



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Posted By: Teken
Date Posted: December 21, 2003 at 9:31 PM
Haldol,

I will simply try to break this down. Please correct me if I am wrong at any point.

The wiper comes on-off without user intervention, correct?

1. Have you inspected *ALL* wires that lead to, and from the wipers?

A: If the vehicle was damaged as you have stated, then it may be possible that one or more wiring harnesses are frayed, or exposed.

Shafing on any body part could be a cause.


2. Ground Points: If any ground point is loose, corroded, or other wise unsound. This too could be a cause.


3. Wire Deteriation: If you do the simple tried and true *Tug & Pull* one each wire. The wire insulation should not stretch. If it does, you have internal wiring that has broken, or have been compromised.


4. Have you inspected the BCM for any loose or improper contact points?


5. Some vehicle use the body chassis as a secondary ground plane to bleed off any leakage.

With regards to the wiper motor, if the unit is unpainted and simply bolted to the frame, inspect the bolts which secure the wiper motor.

If the bolts are corroded, do a simple clean up and reinstall the bolts to see if it makes a difference.


Regards

EVIL Teken . . .





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