I have a 2000 Toyota 4Runner that was converted into a HMMWV type vehicle. When I took it to get inspected, the windshield wipers fuse blew. We started looking for shorts and after wiggling wires for a while, the windshield wipers fuse stopped blowing. Everything seemed to be fine for awhile. Then one day after a rainstorm, the truck would stall when shifted. Once it dried out this problem seemed to go away. Weeks later, after another rainstorm, the windshield wipers fuse blew and the stall when shifting problem started again. This time the ignition switch started acting up, running the starter even after the truck was running and sometimes trying to start the truck without the keys in the ignition. We assumed the ignition switch was bad and replaced it. All the problems seemed to resolve for awhile. Then, they returned. We assumed the ignition switch was bad again and replaced it again. Again all the problems seemed to resolve for awhile. Now, they have returned again. What is ruining the ignition switch? Should we be looking for a bad ground? A shorted wire or componet? Why is this happening usually when there is moisture? Thanks in advance for any help anyone may be able to provide.

 

Someone has made a major fubar of the wiring in your poor vehicle .

Look to all the places anything was added to the vehicle.

Pick up the Toyota Electrical manual for your vehicle.

Good luck take it one step at a time

 

Thanks for your reply. The check engine light came on the last time we had the problem, so we were hoping we could check for a code that could tell us where to start looking. We eventually found the OBDII test interface in a bundle of wires by the gear shifter. It threw a code about the Camshaft Position Sensor. We checked the ground for the sensor and found it was also the ground for the windshield wipers and ignition switch. It was loose, so we cleaned it up and tightened it. We also sealed up the fuse box with some rubber matting. Fingers crossed.

 

I hope you got it!!!

Bad grounds will do strange things

 

It's suppose to rain here tomorrow, so I guess we'll see if it's fixed then...

Thanks again.

 

Well, whatever the issue, it is not resolved. It rained last night and the truck started up fine this morning and shifted into drive just fine. It continued to rain on and off all day today and when I went to go home tonight, the truck started up fine, but stalled when I shifted into drive. Then when I started it up again, the starter continued running after it was already started and it stalled again when shifted into gear...Not sure where to go from here.

 

Do you have a lot of keys on your ring?

I have seen overweight key rings do bad things to ignition switches.

 

Thanks for the suggestion skypilot, but I think we got this solve just yesterday.

We found that water was running down through a hole in the top of the A pillar and gathering by the fuse box. Driving would cause the water to splash up on the fuse box. The water was shorting it out, causing at least 6v to be sent to the starter even after it was started. I guess we didn't have it sealed up as well as we thought!

Thanks again to all of you who offered suggestions.