blown fuse

[acthomp781]

Hello all. 1986 M1009. I searched quite a bit and found nothing specific to my problem. I installed an autometer water temp gauge. I tapped into the tan/white wire for ignition feed, right under the fuse panel. I ran a ground wire all the way to the location where I installed the sending unit, on the same stud that have two other grounds to it, one being a "braided" wire to the firewall. I purchased a pipe flange and installed the sending unit in the right head at the rear of the head. The ignition fuse, number 15 on diagram in 289-20, 4-31, now keeps blowing. When it does the wait light and water in fuel light will not come on, nor will the transmission "kick down" when going uphill. The PO converted to 12 volt system(working on getting back to stock). Otherwise stock system. I also installed a new GP controller card from BMI industries. The vehicle will start right up as I can hear the GP relay cycling, but no wait or water in fuel lights and new gauge not working. The only thing I can think if I put the ground wire for the new gauge to the sending unit and the wire that is supposed to be attached to the sending unit to ground. Thank you for your time.

 

[Tinstar]

Not sure why you tapped into that wire when there's extra ignition taps available on the fuse box.
All you had to do was ground it somewhere under dash, instead of running it that far.
Theres a ground prong with six tabs on it above emergency brake a bit. Use that.

I also have an autometer water temp gauge. Sending unit is in different location as yours but that shouldn't matter.

I suggest start over and don't tap into any other wires.

 

[acthomp781]

Tinstar, thank you for the reply. What are the locations for the extra ignition taps? I will take your advice and start over. Where did you install your sending unit? Just curious. Thanks again.

 

[Tinstar]

Crawl under and look at the fuse box.
Youll see the open spots.
Someone might post a diagram to help. It's also in the TM.

I tapped the side of the water pump.
Not the best location for accuracy I know, but it works.
I have a brand new HMMWV crossover that I will install someday. Will relocate water temp sender then.

 

[M813rc]

What are the locations for the extra ignition taps?

Circled in red.

Cheers

 

[MarcusOReallyus]

Not sure why you tapped into that wire when there's extra ignition taps available on the fuse box.
All you had to do was ground it somewhere under dash, instead of running it that far.
Theres a ground prong with six tabs on it above emergency brake a bit. Use that.

I also have an autometer water temp gauge. Sending unit is in different location as yours but that shouldn't matter.

I suggest start over and don't tap into any other wires.

Yep. You made it too complicated. Keep it simple. Everything he said, plus, make sure you clean up that 6 prong ground point. Take it off, make things shiny clean, add some dielectric grease, and put it back together.

 

[acthomp781]

Thank you all for the replies. I unhooked the gauge this morning from the tan/wht wire. But when I was driving home from work, I was going up a hill, and I pushed the accelerator pedal close to WO and the transmission "kicked" down for 1/2 second only. I got home and checked the ignition fuse, number 15 on diagram and blown again. I am thinking maybe something with the downshift solenoid or downshift switch. I am going to do some searching for those two items next. Thanks again.

 

[acthomp781]

I am updating this post d/t I found what was causing the blown ignition fuse. I cleaned some ground points, took apart the downshift switch and cleaned it. I test drove the vehicle and the fuse blew again when accelerator pushed to floor. I got under the truck and followed the orange wire from the connecter at the side of the transmission, and saw a bare spot, the wire had been just twisted together, the bare spot was touching the rear of the head/block, and when the engine moved from the downshift the wire touched and blew the fuse.

 

[MarcusOReallyus]

Yeah, that'll do it!

Thanks for the update!

 

[dougco1]

That's what the fuses are for. They tell you that all is not good here when they blow.