help... fuse #29 (1998 expedition) keeps blowing?
 

i have tried larger fuses (up to 15A) but that even gave way to overload. i haven't been able to reproduce the overload at will but am still looking into it and will report anything i find worth posting.

in the manual it says this 5A fuse goes to the...

Autolamp Module?, Instrument Cluster, and the Transmission Control Switch?

...the only one i know anything about is the instrument cluster as it's what is immediately noticeable since all the gauges (even the odometer) stops after the fuse blows.

i don't seem to have any transmission issues other than at times it seems like it'll take it a little longer to shift from gear to gear with the rpms going up the the 3k - 4k area before it shifts.

not sure what the autolamp module is?

any ideas what could be causing this guys?

tia!

I know some of the expeditions had wiring problems around the back of the engine near the firewall. I would look the wiring over very carefully around the back and on either side of the engine. Make sure it's not laying against the exhaust. That transmission control switch wiring could be the culprit if the wiring for it runs down the rear of the engine.

thanks for the reply.

well this doesn't sound like it's gonna be an easy fix =(

would you happen to know where i could find a diagram or even a pic of the area you're referring to?

i just got a digicam and i'll take a pic of where i think you're talking about. i'm mainly concerned with the TCS like you mentioned. you said it runs down the rear of the engine - where would be the best place to take the pic - from above (under the hood) or below (under the truck)?

thanks again m8.

nm, i just checked the Haynes manual and it looks as though the TCS is the same thing as the overdrive button/switch on the shift lever.

the Haynes says to first check fuse #29. then it says to remove the TCS (which i can't do b/c i'd need jackstands which i don't have) then test the resistance of the module with a multimeter.

it also says i can check it by pressing the TCS and checking to see if the TCIL (Transmisison Control Indicator Lamp) comes on and stays lit or if it flashes.

if it flashes there's either a sensor failure or a short in the EPC (Electronic Pressure Circuit) and in either event it needs to be serviced by a dealer.

i'll do these few things and see what gives.

thanks again for your help.

If it's blowing the fuse, like I said I would do a visual. If the Haynes manual tells you the location of the tranny switch or whatever it is, I would find it and then with a flashlight carefully follow the wire up with your hand and see if it is rubbed through anywhere.

I figured an expedition would be high enough off the ground where you could crawl under there anyway, but if you need more clearance, see if you have a small ditch out near the road at the front of your house or something, and drive across it to straddle it. Then crawl down in the ditch. This should give you a little bit more room to look around.

yes, there is plenty of clearance - i just need to know where the darn thing is on the transmission.

this manual has pictures of EVERYTHING accept this darn TCS! this is comical.

anyone know where the TCS wire connects onto the transmission?