2nd Gen Non-Engine/Transmission Twilight zone electrical problem

[Diesel Dan]

first the good news,

Santa brought me 3 Dirpocal white guages along with the awsome "Rods Pod"

The install went well. connected the boost and egt ones for now and the transmission will be soon after deciding the best set pickup point. Went on to the illumination part and that is were the problem reared its ugly head.

Soldered all three black wires together with a black wire for running to the power source. Did the same for the red wires.

My truck had a autometer egt guage on the pillar that i had installed at a diesel shop a while back and i thought would be a great place to get the illumination source as it worked great and dimmed with the dash dimmer. I pulled these two wires down from the pillar and hooked them up. Everything worked well until i realized that the guages were not dimming with dash lights. The next day i realized that the radio readout i. e. 98. 7 or time was / dimming when i applied the brakes!! like i was turning on the parking lights. upon further review that night i determined that



1. i have no dash lights

2. i have no running lights

3. when i apply the brakes my dash lights come on as do my front running lights and my cab clearance along with my rear brake lights :--) I wanted to do something special with my cab lights but this is not what i had in mind

The guages do not have any wireing info and thru the process of elimination the finger points to the two mystery wires that were illuminating the old guage. One is white the other is black. There source is unknown and not locatable behind the the fuse panel.

How can the fuse panel be accessed besides the lower cover? as i need to investigate further.



Has anyone seen anything like this???

It has me stumped



Fire away with the questions and suggestions.



Thanks in advance



Diesel Dan

 

[Tardog]

Haven't installed any gauges of these sorts but... ... Should 3 black wires go to ground and the red wires go to power????? if both the black wire and red wire run to a "power " source wouldn't this cause things not to work? (maybe it's just the way you worded it). But it sure sounds like a back feed problem of some sort? good luck, Cheers

 

[Diesel Dan]

Tardog,

It was the way i worded it , sorry. the black wires were connected to the black wire from the old gage and the red wires were connected to the other(white) wire from the old gage. I thought it was too slick to be true. oh well



thanks



DD

 

[Alan Reagan]

Disconnect from the black and white wires (your old gauge wiring). Sounds like they may have used an AC color code where white is neutral (or in this case ground) and black is hot). Check to see which one is the hot wire and rewire accordingly. It's a ground problem. I'm surprised is hasn't popped a fuse.

 

[JTMcCracken]

Man, that is weird. I had a little talk with Rod Sterling, and his suggestion was to try not to use the brakes. ; ) JTMcC.

 

[Diesel Dan]

Alan,

there is no change when i disconnect both of the wires. Do you or anyone else know how to take the dash apart to access the fuse panel on the backside?



DD

 

[Tardog]

D. D

So this problem popped up only since you wired in the new gauges Right?

And you still have the problem since you disconnected? It seems as though there is power coming back through a ground from you brake lights and that is suppling your dash and Cab lights when you apply the brakes and screwing every thing else up or something else (seeings how you haven't touched the brake wiring circuit. ) I checked my shop manual and it says for a 97 that the fuse block can be removed from under the instument panel by removing the lower steering column cover/kneee bolster. I'm gonna look at the wiring in the manual to see if i can help out. What year is your truck?

 

[Diesel Dan]

Tardog,

You are correct. The problem came after the gage install. After i realized that they were not dimming, i reversed them but it did not help. my truck is an 01 but i do not know what happened to my sig.



Thanks for the help and keep racking the brain. two have got to be better than one(mine)



DD

 

[illflem]

Sounds like you're hooked up or grounded out to the brake light wiring somewhere. Places to check are the brake pedal switch and the trailer brake controller wiring as they would be the easiest to accidently ground out while fooling around under the dash.

 

[fkovalski]

Hey DD- I am going to go out on a limb here: illflem is right about being hooked to the brake somewhere. Humor me and change BOTH your rear taillights. I had a similar problem working at a Chevy dealer years ago. A fellow mechanic told me to do this after telling him the symptoms. I think that the work you did is NOT related to the light problem (insert Twilight Zone theme song here…) It IS possible that the filament of one bulb disconnected and has fallen to cross the other INSIDE the bulb. I would never have believed this until I looked at the bulb and sure enough, one could see the newly created circuit! Hope this is all it is before you do a teardown! -frank

 

[JPS]

wiring problems

Keep in mind, a bad ground can show all kinds of weird things. jps

 

[Diesel Dan]

fkovalsky,

That is very interesting as i forgot to mention that santa also brought me a pair of 55 watt brake lights which i installed on 12-25 I am going outside to swap them out. and i will advise the results.



Keeping my fongers crossed



DD

 

[Diesel Dan]

Correction,

that was 55 watt backup lights. But it looks like i installed one in the wrong socket( possibly too much egg nogg ) now the parking lights don't come on with the brake pedal butt the wont come on at all. Checked fuse # 1 for parking lights and it was good. replaced it any way but same result. now the question is how do get the parking circuit to work????



DD

 

[Alan Reagan]

If I remember correctly and I've only done this once, to remove the kickplate this is one bolt toward the firewall and then a screw at the door plate. The kickplate will then slide backward and come out.

 

[Tardog]

Diesel Dan



I'm sure you checked but... ... . Are all the parking lights good and not blown? (sounds far fetched, just a thought) Would it be easy to pull the headlight switch to determine if you have power here for your parking lights?(switched ground?) Are the 01's suspect to the bad headlight switches? But this will tell you if it is a distribution problem or a supply problem because you mentioned that other lights came on when other things were happening,could quite easily be a fried switch?

 

[Extreme1]

This may not apply but I had a similar problem when I hooked up to someone else's trailer. I turns out the ground to the light switch had fallen off the switch (had the recall done earlier in the week). Worth a look!

 

[Diesel Dan]

Tardog,

I will try this tonight but do you or anyone know what the wire /color code is for this circuit on a 01?



Thanks to all



DD

 

[Tardog]

Diesel Dan



So how goes the battle?

 

[Diesel Dan]

Tardog,

Thanks for your concern. I fixed it this weekend.

Here is the conclusion.



I installed one of the new 55 watt backup lights into the wrong socket(running light/ Brake light ) I am blaming the holiday cheer( egg nogg)That is my story and i am sticking too it! this ultimatly joined both circuits together and caused the problem of the running lights to come on when i applied the brake. this eventually blew the fuse. The problem was i didn't realize that there was an additional set of fuses under the hood. Checked and double checked the fuse in the cab and it was fine. it finally hit me in the shower to check under the hood as i thought there was some fuses but i have never had to trouble shoot any other electrical problems so it was out of mind. the fuse for the circuit under the hood was blown and wala, problem fixed. I have never been soo happy to find a blown fuse in my life



The only other mystery is that even when the illumination of the gages is hooked up to the dimmer circuit the gages don't dim. I have DiProcal working on it as we speak.



Thanks to all that helped and especially dekevdog for faxing me all those page of schematic's. And yourself as well.



It still baffles me why there are multible fuses for a single circuit



Oh well



DD

 

[Tardog]

I know what you mean by relief. There's nothing quite like thinking you have a major serious problem and then you fix it with something as similar as a fuse. Multiple fuses have there place. Easy access fuses are great for us joe average people. I think the extra fuses protect the circuit in different locations. Just think of what would happen to wiring, lights etc. if it got shorted out on the high side of the fuse. melted wiring and plastic sockets, fried bulbs and who knows about other electronics. Glad to hear you got it fixed. cheers