Where in The World is TheTransfer Relay Switch?

[intense1]

I have had a prob with my rig not going into 4wd High. Today I went through the FSM with a friend that can read the wiring diagrams and we trouble shot the solenoids and the actual switch on the dash. Both work. The other piece of the puzzle is the switch. We couldn't find it.
Anybody know?

 

[2mbb]

Did you look under the cover where your fuses are? If not, the diagram below shows that they are up under the dash, near the steering column, but I can't tell from the diagram whether they are to the right or left of the column (my guess would be to the left of the column). Also there is some electrical stuff hidden behind the kick panel on the drivers side.

In the diagram below it's called the "drive" relay.

 

[Kynot62]

Have you checked that it's not the diaphragm causing the problem?

You don't say which switch you can't find, the FSM mentions 5 switches. You have eliminated the dash switch and I don't think you mean the Neutral Start switch so look at page TF 5 and you will find the Transfer neutal switch and the L4 position switch on the right side of the transfer case above the rear driveshaft. The only other switch is the 4WD indicator switch and it is just aft of the diaphragm cylinder assembly, page TF 22.

Are you sure its not engaging? I had a problem with burned out light bulbs on the dash switch and indicator. Hit the switch with the engine running, hubs unlocked, tranny in neutral, park brake on, reach up and grab the front shaft. If it engages, it could be an idicator problem and if it doesn't it could be the vacuum system or electrical.

Best of luck
Tony

 

[intense1]

2mbb, Thanks for the diagram.
Kynot62, I checked the dash switch and the 2 diaphragms on the firewall IAW the FSM. Both checked out good. I get the 4WD light on the dash when I put the lever into 4WD. I have 4WD Low. The dash switch won't switch it into 4WD High.

 

[Kynot62]

What you called diaphragms on the firewall are actually vacuum switching valves. Will your dash switch make these switches operate? If yes I don't think its the transfer control relay.

If you have not found it yet I think I located the transfer control relay. Look in your FSM on page BE 9 at the relay block, there is a relay for "front drive". This block is to the left of the steering column in plain sight. Whats confusing is the wiring diagrams call this the front drive relay and the transfer case section calls it the transfer control relay, at least thats what it looks like to me. You might have your friend confirm this.

My other thought was that the diaphragm on the transfer case that does the actual shift in and out of 4H might not be working. This could be caused by a vacuum leak or a bad diaphragm assemby. If the diaphragm is OK you should be able to check it by shifting the transfer case with a hand held vacuum pump.

Hope this helps, let me know what you find out
Tony

 

[intense1]

Will do, Thanks!

 

[intense1]

SO:
Ops check on the 4WD switch, the firewall sylinouds, and the infamous transfer control relay all came out good. That leaves me the actual diaphragm, and the vacuum lines.

 

[Randy88FJ62]

SO:
Ops check on the 4WD switch, the firewall sylinouds, and the infamous transfer control relay all came out good. That leaves me the actual diaphragm, and the vacuum lines.

Are your vaccuum lines in good shape? That would be the best bet. My truck has 281,000 and the diaphram is still good. Hoses would go first IMO.

 

[intense1]

I need to check on the ones going to the t-case. The ones on the firewall are good. I'm assuming that just the ones coming out of the sylinouds will go to the diaphragm.