Vehicle: 1997 XLT 4.6 V8 Std Cab 2WD Auto.

Problem: While trying to find the beautifully hidden hazard lights flasher relay to replace it, I removed the part of the dash under the steering wheel. Left it hanging for a couple of days. For some reason the truck battery completely discharged during that time.

Disconnected the NEG battery terminal and used an ammeter to check for a major short. Found none. The meter went to about 500 ma for a few seconds as the computer booted and then down to about 25. This is normal.

Jump stated the truck and it charged back up in about 40 minutes of run time.

Gave up on finding and replacing the relay and put the dash back together. The battery stays charged but now two new related problems came up. No brake lights and no hazards or turn signals.

Owner manual says Fuse 1 in the dash fuse box controls that. Pulled it and it checks out fine. With the fuse back in its slot, I read normal battery volts on both sides.

Anyone ever had anything like this go down? Any help will be appreciated! I know that these accessories are on the same bus. Everything else electrical in the truck works perfectly.

Thanks

 

Check the MFS connectors and pins in the connectors. All those new problem functions go through it. You may have pulled a cable or connector.

 

Sorry, I'm clueless as to what an MFS connector is. I have access to a Chilton manual, but its wiring diagrams are not very clear. Can you tell me what one is? Tracing the wires in that under-dash spaghetti bowl is for much younger dudes than I.

It is becoming obvious that I didn't create a short, but an open circuit or a completely shot flasher relay could cause the same lack of operation. I do not think there are any other fuses in the particular circuit. The missing stop lights confuse it further.

Thank you.

 

MFS = Multi Function Switch which is the turn signal lever.

 

Thanks, Tiny. Found a new clue this morning. If the Hazard Lights button is fully depressed, the turn signals function normally (still no hazards). Getting close to your suggestion being in the right direction. Got into this mess in the first place because the hazards didn't function. Might not have had full brake lites for a long time. The upper brake lite on the Leer cap seems to work to some degree, which kinda says the brake-on switch is OK . Not much left but the MFS and hazard lite sw. Will check further, but I smell a defective Haz Sw.

There are no problems in this world, only people!

 

MFS includes the hazard lamp function.

 

Thanks, Project! Found a picture of the ***'y and now also know how it's wired inside. Also learned how easy it is to replace. Starting to become convinced that one flasher relay does it all and MFS routes the current.

I might even find the elusive flasher when I pull off the column covers.

 

That is correct.

Not there. It's behind the instrument panel, above your right foot.