Need help 9/11 Electrical Gremlin

[ChikhaiBardo]

So I am trucking my '89 F250 7.3 IDI from Fairbanks, AK to North Carolina. I made it to Calgary, Alberta yesterday and started having the battery dummy light on the dash flash when RPMs would drop on the highway and would come on constant at a stop light. I replaced the pigtail to the voltage regulator (only about 2 months old Motorcraft) and ran a new ground and thought it had solved the problem until it started happening again. I found a replacement alternator here in Calgary and got it swapped and all was running great. Measured voltage with a multimeter and even the cluster VM was happy sitting straight up and down. All was great until I went to the airport and out of habit pushed my parking break down (it doesn't even work that well) and as soon as I got one click into the ebrake my VM, oil pressure gauge and cluster lights go out. I am at the Stampede all day tomorrow with my mother. All cables in the truck are brand new with multiple brand new grounds. I am hoping this is just a simple fix, but would love and very much appreciate some opinions or ideas to attempt for tomorrow night when I can dive into it. Please and thank you, guys and gals! This truck has to make it another 3,000 miles roughly to NC. I would like to do it with being able to see my cluster and hopefully it's not anything major. Maybe a fuse? I haven't tested anything yet. It's just parked in the parkade down the block. Just irks me that this happened right after my new alternator install. Fixing one problem to have another pop up. Please help thanks!

 

[DaveBen]

The dash lights are on the same circuit as the running lights (Tail lights). Not sure why the parking brake has anything to do with it, but I have seen stranger.

 

[Thewespaul]

Check your grounds under the dash, I’ve had messy grounds cause electrical issues and when the brake clicked past it’s first detent it may be completing or rupturing a circuit

 

[towcat]

how old is the headlight switch and plug?

 

[ChikhaiBardo]

I will check all these thanks guys. Truck is fairly new to me so not sure on age of things being replaced.

 

[ChikhaiBardo]

Just to clarify. Pressed the ebrake and lost voltage meter, dash lights, and tachometer. Speedo and fuel gauge still work.

 

[DaveBen]

Unless you have a short to the E-brake pedal, there is no connection with the running lights (Tail lights). I am guessing you have a short to the E-brake.

 

[ChikhaiBardo]

Unless you have a short to the E-brake pedal, there is no connection with the running lights (Tail lights). I am guessing you have a short to the E-brake.

I will check wiring around e brake pedal. Would finding the short magically make gauges and dash light return to normal or do they run on a fuse as well? I will check fuses tonight as well.

 

[nostrokes]

I had the exact same problem with mine. Turned out to be a auxiliary wire on my pioneer stereo for lights on an amp and it popped the running light fuse....

 

[ChikhaiBardo]

I had the exact same problem with mine. Turned out to be a auxiliary wire on my pioneer stereo for lights on an amp and it popped the running light fuse....

My system is stock other than upgraded 1/0 cables and an LED center light/map light. I'm going to investigate tonight around the pedal and look for exposed wires. I will pick up some more fuses from NAPA as well and replace as I uncover. Still looking and reaching for anyone else with duplicate or same issues. Thanks guys! Only 2,000 miles to go and she can get a rest.

 

[ChikhaiBardo]

I don't understand why you guys are mentioning the running lights and tail lights unless they are on the same fuse? Also realized today that the fuel gauge is broken too. I unplugged the cable to the ebrake and had no non working fuses. Any other ideas? All the cables appear to be fine and no exposed copper. I'm running out of ideas. I have to replace the vacuum pump when I get back into the USA. So the cluster lights and gauges failing with the ebrake thing can kind of go on the back burner for now, but I still am open to and very appreciative of any other ideas. Thanks again guys.

 

[ChikhaiBardo]

Ok finally found a fuse I had skipped. I got my dash illumination back but still none of the broken gauges have returned. I am keeping the ebrake cable unplugged. Is it possible for something inside the cluster to "blow" that isn't in the fuse panel? I have never had this year model pulled apart before