If a relay is bad, will it still pass through current?

I wanna make sure the relay is not bad. There are 4 or 5 relays in the dash area of the passenger side behind the air bag. When I select 4H I can hear clicking. When I select 4L it engages 4L. The clicking to me makes me think the relay is working correctly.

The switch is not bad for the 4x4, I replaced it with 4 different ones to make sure that 's not it. One of those was a new one from autozone that had 4 positions and I was able to select 4H with it. But when going back to the stock switch (3position) it does not.

I was just curious if perhaps the relays was bad and was not letting the current pass through for 4H but will let it pass for 4L and 2H with the stock 3 position switch.

I'm leading towards the GEM, but want to rule out the relay.

 

Usually, if a relay is clicking, it's working. Obviously putting a voltage meter on it would be the best way to verify that.

 

since the switch sends out different voltage for each position, is that the possibilty of the relay being bad for that determined voltage? When you select 4L and 2H there is no clicking sounds just those gears engaging.

I guess to me a relay either works or it doesn't. Is there only one relay to activate the 4x4 options? There are 3 small ones and 1 or 2 large ones on the same strip in the dash on the passenger side.

 

There is more than one relay, check my gallery, I put the diagrams there.

 

Thanks....everyone else told me there was only one relay and the vacum things under the battery box.

Since I can activate 2H and 4L it's deff something electrical specially since with a different switch I can select it but it has to be a 4 position switch witch to me still points to the GEM.

I'll look over those diagrams and see if there is anything helpful.

Thanks,

 

Not sure how you are making the 4 position switch work in connector C230, that only has 3 positions on the switch, illumination for the switch, ground for the switch, and the GEM feeds. Unless you cut the ends off at C230 to be able to install the wrong switch, don't know how you are getting it to work correctly.

did you bench test the switch or the relay ?
pin 2 to pin3, Ohms setting on meter.
2H = 3.9K Ohms of resistance
4H = 1.1K Ohms of resistance
4L = 360 Ohms of resistance.
If those check out, no need to mess with the switch any longer.
The 4 position switch you used, what is the resistance when using the selection for 4H, and when you say it worked, how did you confirm you locked into 4 H on the transfer case, and did the front axle lock into place ?

Test the relay, apply 12V over pins 1& 2, and at this point 3 to 5 should have 0 ohms of resistance ( or close to it ).

The "clicking" on the relay, is this with the switch in one position ? If so there is a problem with the relay, as there should be a single click ( if you even hear it ), until you change the position on the switch again.
This is for the single Relay in the ESOF circuit. The other "relay" is the transfer case shift relay module, which is 2 relays in a single module, made to reverse the voltage flow to the transfer case ( in the same way the power window switch reverses voltage to get the window to go up or down ). This moves the shift motor from Lo to Hi and Hi to Low. Controlled by the GEM.
This looks to be behind the instrument panel.
The RPO relay block is under the oval, and this is there the transfer case electric clutch relay is located. This is a standard ISO relay.

Not sure some of your assumptions are correct, and installing the wrong switch is not proving anything. Might want to start with checking the switch, and the single relay. Testing the transfer case shift relay module is going to be a bit mroe involved.

 

I haven't checked for resistance....but to answer some of your questions.

When you select 4H all it does is click, click , click , click. If you removed the part in upper portion of the dash on the passenger side you can hear/feel the clicking. It does not click ones it just keeps clicking till you select another selection. When back to 2H or 4L it stops clicking. The light for 4H does not come on but does for 4L.

Now for the 4 position switch. I went to autozone and under my specific year model etc, when I got the switch I put it on it fit in the plug fine just the plastic mounting did not fit correctly. It had 4 positions. In the second position it did the same as in the factory switch jsut clicks. When in the 3rd position, I did go under the car and the front was locked...I grabbed the half shaft and it would not move and the light came on for 4x4 when I had it in the 3rd position. I meesed around with that switch several times, in the last position, 4L, I heard the mechanical part move and I check below on the half shaft and the light came on for 4x4 low. When putting it back to the 3rd position the LOW light went out and you could hear the mechanical part disengage again. It's really weird that's for sure.

I also replaced the transfer case motor, that didn't fix my issue so I thought it was the switch and didn't fix it either.

I took the autozone switch back because obviously it was the wrong one, and got one from the dealer. Back to clicking sounds.

If you have time, any way you can take a pic of the relay your saying might be bad since all it's doing is clicking. My guess it's the one in dash area on the passenger side since that's where the clicking is coming from right? But there are 4-6 relays/fuses in the same area and I dont want to replace all since I'm sure they are not cheap.

I'd rather change that then point to the GEM bacause that's what I'm leading toward.

 

This might be a good place to start, rather then changing stuff for the heck of it, as you have done so far. Swapping parts does nothing but lengthen the diagnostic process.

Don't bother saying what happened with the wrong switch installed, diagnostically this is unless information.

I don't have a 4x4, so I cannot take a picture of anything. If you touch the relay while it is clicking, you can pull it and bench test it, rather then replacing it for the heck of it, again this is diagnostically unless swapping parts for the heck of it.
Why are you leaning towards the GEM being bad ?
You have not tested the switch nor the relay in question, but you are guessing it is a 700.00 part on the truck ?

If you want to take a step by step approach to diagnosing the problem, I will try to help you, if you just want to start swapping parts, trying items that are not meant to be on the truck, and guess at what is wrong, you don't need my help for that.

let us know what you want to do.

 

I don't have a 4x4, so I cannot take a picture of anything. If you touch the relay while it is clicking, you can pull it and bench test it, rather then replacing it for the heck of it, again this is diagnostically unless swapping parts for the heck of it.
Why are you leaning towards the GEM being bad ?
You have not tested the switch nor the relay in question, but you are guessing it is a 700.00 part on the truck ?

If you want to take a step by step approach to diagnosing the problem, I will try to help you, if you just want to start swapping parts, trying items that are not meant to be on the truck, and guess at what is wrong, you don't need my help for that.

let us know what you want to do.[/QUOTE]


I'll explain why I did and why I assumed the things I have so far. Let me start though, I'm not a big electrical person, I'd rather work with mechanical stuff....unless the directions are pretty detailed. Having said, I do want to diagnose the issue without replacing the parts.

Now:

I first thought it was the transver case motor since the thing was rusted bad. Figured I can hear power going to the relay (clicking sounds) so it's gotta be that since there are no other relays beteween the relay and the motor. Now, I took the new motor and applied power and it didn't move either so I know the motor is not getting power for 4H or not enouph. I need to check the voltage as you suggested.

Switch was replaced because a few on here suggested that was the item since the GEM is actually sending the signal since 2H and 4L are working.

Reason for thinking its the GEM, a few weeks back both windows were down and would not go up. I had to put direct power to the window motors to get them up. They are up now. Suggestion I was given is to replace the switches (down, up) I did and still nothing. I also noticed the cruise control is not working. I never use it and just go the truck this summer so it might hot have worked for a long time. Either way with this being an electrical thing, that is why I said I was leading towards the GEM/fuse box.

Now for the relay, I tried feeling the relay when it was clicking. There are about 4-6 right by eachother, the clicking is so loud they sound and feel like they are the one doing the clicking. I dont know witch one goes to what or else I would pull 1 at a time till I get the right one. I just dont want to pull one that is very important and screw smothing else up.

I'll try your suggestions and post back.

Also, you were talking about the relay, is the clicking suppose to happen or is that a sign of a bad relay. If the relay is bad, doesn't it just do nothing. And if it were bad, would it relay some signal jsut not everything? I was tole the signal for 2H and 4L goes through the same relay. Is that correct?

Thanks again,

 

A Relay can click once when power is applied to it, and once when power is removed. If the relay is clicking continually, then that is either a problem with the relay ( coil cannot hold the contacts in ) or the coil has power being applied and removed. Either way, the relay is not working as it should be.
If the relay makes no click noise when power is applied, then it is almost always dead ( or power is not being applied at all, hence the bench test of the relay ).

The single relay ( that is part of the ESOF ) is for the transfer case clutch. This activates the magnetic clutch in the transfer case.
There is a Transfer case shift relay module that seems to be behind the dash that is the hi lo portion of the transfer case.
So while there is one relay in each electrical path, I would say both have to work for the transfer case to select a high or low gearing. The hi is one of the 2 relays in the module, the lo is a different relay in the module ( looks to be the relays reverse the polarity to the shift motor).

Now the clutch relay could be getting and loosing ground from the GEM, but pulling the relay and bench testing it will tell. I cannot find a diagram of all the relays under the oval, towards the passenger side of the dash. If you can see the relay socket, it is the one that has orange, white w/ light blue, dark green w/ light green and brown wires to it. I know the door lock relays for the RAP are also over there, and I think the window OTD relay. Might want to check to see if any of the wiring into the RPO relay block are damaged, as this is starting to sound like part of the problems associated with the additional list provided.

The Cruise Control can be another item.
Here is the test procedure I have but I have only tried this on my old 2001

Might want to take a quick look at this, if it does not test out, that should be a different thread.

Power windows, again could be another problem. Usually the GEM when soaked ( water damage ) will have other gremlins like the blower motor runs with the key off, the windshield wipers run without being turned on, the radio will stay on, etc. The windows could be a symptom, but I would guess problem with either of the switches, or ground to them. Again, a quick look at the wiring would be in order, but this could become another thread.

Start with bench testing the 4x4 switch for the resistance, and let's hope this did not put a bad voltage level into the GEM, and do something else.

Also a close visual inspection of the wiring to the RPO relay block under the oval on the passenger side of the dash.

Good luck, let us know what happens.

 

I got home late last night and wasn't able to get the voltmeter out and o all the testing, but here is what I did do.

I removed the oval and saw the big relay and the 2-3 smaller ones. The big one was square an the others were smaller rectangular ones. I had one of those square ones in the garage so I switched them out and tried it it fixed anything. No luck. I then switched the relay's of those 2-3 between each other and started the truck up and switched it to 2H. Nothing except the clicking. It's just keep clicking, clicking, clicking. Since I moved all of the relay's/fuses not sure if those little ones are considered relay's or fuses, I wouldn't think it was them because all of them in different positions did the same thing.

My radio works, my blower works, winshield wipers work as they should as well.

Testing the switch do I remove the panel and just tap in the wires and read the current going through when selecting the desired gear (2H,4H,4L) or is there a better way.

I had planned on removing the GEM this week and cleaning all the contacts and visually inspect it as well.

I'll try to do some testing and report back.

Thanks.