[spinshop]

This week end I put a new Autowire dash harness in my car and I have a few problems.The head lights dont work but the parking lights do and when I push the lighter in the directional lights light up.Could it be a bad ground?If so where would it be?And when I finally got it running it ran like it was loosing spark and then catching spark.
I have an MSD ignition.
Thanks for any help

[aawtech]

Do you have your dimmer switch plugged in yet? You should have voltage on the lt. blue wire when the H/L switch knob is pulled out. Let us know. The lighter shouldn't normally effect the dash lights at all. That's a battery hot feed and is hot even at rest with the car turned off, strange. A bad cluster ground will cause many strange problems, yes. There is a metal trace several places on that cluster so that when things are all bolted in, everything has a ground. If any or all of them are missing, you will have issues most definately.

Donny

[spinshop]

Originally Posted by aawtech

Do you have your dimmer switch plugged in yet? You should have voltage on the lt. blue wire when the H/L switch knob is pulled out. Let us know. The lighter shouldn't normally effect the dash lights at all. That's a battery hot feed and is hot even at rest with the car turned off, strange. A bad cluster ground will cause many strange problems, yes. There is a metal trace several places on that cluster so that when things are all bolted in, everything has a ground. If any or all of them are missing, you will have issues most definately.

Donny

Yes the dimmer is plugged in.I will check the voltage when I get out of work.The metal traces?Are they the metal strips on the top and bottom of the dash bezel?They are both there and screwed to the dash.I did think it was strange the directional lights lit when the lighter was in, it did the same thing with the old harness and the head lights did`nt work either thats why I am changing everything.I painted the dash could that be the problem or am I wrong because the clips that the bezel screws to is digging in to the dash or are there more grounds that I dont know of?
Thanks Donny

[spinshop]

OK, finally got back on the harness.Got the head lights to work.Seems I didnt hook up the ground at the end of the forward harness .Now,when I pull the switch out the blinker lights still light up when I turn the knob to light the dash, the lights dont go on on the dash until I turn the switch all the way to turn the dome light on and as soon as I turn the knob, the temp gage goes all the way to hot .When I push the lighter in with the head light switch off the blinker lights light up and the lighter does`nt work and the temp gage goes to hot.So, I thought I would pull the whole cluster out to see if the 2 metal strips were on the bezel.When I did ,I pulled the switch out and the cluster lights lit up and the blinker lights were out and the lighter worked.Now the cluster is`nt grounded and the lights on the dash work as soon as I push the cluster back in the dash the blinker lights light up again.
Can someone PLEASE tell me what I am doing wrong?
Thanks

[aawtech]

You are getting some type of a back feed ground. There's no question about it. They can be a big problem to figure out. Short of retracing everything step by step, I can't think of anything else to tell you. You problem could actually be that the parking lamp assemblies are not grounded well and when the parking lamps are activated, they are back feeding on the lt. blue and dk. blue turn signal wires and finding a ground all the way back at the dash assembly which lights those indicator lamps. I know that sounds crazy, but electricity is like water in that it will follow the path of least resistance. That's what is happening in your instance unfortunately.

Donny

[spinshop]

Originally Posted by aawtech

You are getting some type of a back feed ground. There's no question about it. They can be a big problem to figure out. Short of retracing everything step by step, I can't think of anything else to tell you. You problem could actually be that the parking lamp assemblies are not grounded well and when the parking lamps are activated, they are back feeding on the lt. blue and dk. blue turn signal wires and finding a ground all the way back at the dash assembly which lights those indicator lamps. I know that sounds crazy, but electricity is like water in that it will follow the path of least resistance. That's what is happening in your instance unfortunately.

Donny

Thanks Donny
I guess the best thing for me to do is to get a new forward harness?
Your screen name,aawtech.Do you work for American Auto Wire? That is where I got the dash harness.I was planning on getting a forward harness but I thought I would save some money trying the old one.

[aawtech]

Originally Posted by spinshop

Thanks Donny
I guess the best thing for me to do is to get a new forward harness?
Your screen name,aawtech.Do you work for American Auto Wire? That is where I got the dash harness.I was planning on getting a forward harness but I thought I would save some money trying the old one.

Yes I do work there. I'm the R&D Engineer. Before giving up on your old system, thoroughly check that all of your parking lamp assemblies are tight and installed properly. Check them for continuity back to the ground post on the battery. Hopefully they have not been painted with 2 stage paint or have powder coated. If so, they will not get a ground and that would more than likely be the cause of your issue.

Donny

[spinshop]

Originally Posted by aawtech

Yes I do work there. I'm the R&D Engineer. Before giving up on your old system, thoroughly check that all of your parking lamp assemblies are tight and installed properly. Check them for continuity back to the ground post on the battery. Hopefully they have not been painted with 2 stage paint or have powder coated. If so, they will not get a ground and that would more than likely be the cause of your issue.

Donny

Thanks Donny
I will check to be sure they are grounded this week end.

[spinshop]

Originally Posted by aawtech

Yes I do work there. I'm the R&D Engineer. Before giving up on your old system, thoroughly check that all of your parking lamp assemblies are tight and installed properly. Check them for continuity back to the ground post on the battery. Hopefully they have not been painted with 2 stage paint or have powder coated. If so, they will not get a ground and that would more than likely be the cause of your issue.

Donny

Donny,
I checked the grounds on the parking lights and there were a few broken wires on the tail lights.So I unpluged them and I still had a problem.So,I took the harness out again and the brown wire that goes to the flasher on the fuse box was out.Before I put this harness back in,do you think THAT could have been my problem?
Thanks Tim

[aawtech]

Tim, that brown wire is the accessory power to the flasher mounted down the harness. If it was not plugged onto the blade inside the box, you would not have had any power to the flasher (purple and brown wires). That really shouldn't have had any bearing on those indicators lighting up on the dash though.

Donny

[spinshop]

Originally Posted by aawtech

Tim, that brown wire is the accessory power to the flasher mounted down the harness. If it was not plugged onto the blade inside the box, you would not have had any power to the flasher (purple and brown wires). That really shouldn't have had any bearing on those indicators lighting up on the dash though.

Donny

What if the wire was hitting another live wire?

[rkd]

From my 66 experience, and 40 years of old Fords, the grounds are the key. Especially on your vintage Chevelle. The light bulbs ground through their case to the lampholder and you have to have a good ground from there to the light housing to the body. My tail lights and front parking/turn lights were a b-tch to get clean and grounded. Then stuff like wipers and the dash bulbs ground via the metal dash. There is also a brass or metal strip that grounds the cluster to the metal dash.

All that said, I usually try to exactly trace the specific circuit I am working on, so I can go through it logically. Did not do that Sun, resulting in my wire frying dash removal epsiode.

Mine sits outside so corrosion marches on daily and has to be cleaned occasionally. Those freshly cleaned grounds seem to re corrode amazingly soon.

[spinshop]

Originally Posted by rkd

From my 66 experience, and 40 years of old Fords, the grounds are the key. Especially on your vintage Chevelle. The light bulbs ground through their case to the lampholder and you have to have a good ground from there to the light housing to the body. My tail lights and front parking/turn lights were a b-tch to get clean and grounded. Then stuff like wipers and the dash bulbs ground via the metal dash. There is also a brass or metal strip that grounds the cluster to the metal dash.

All that said, I usually try to exactly trace the specific circuit I am working on, so I can go through it logically. Did not do that Sun, resulting in my wire frying dash removal epsiode.

Mine sits outside so corrosion marches on daily and has to be cleaned occasionally. Those freshly cleaned grounds seem to re corrode amazingly soon.

I think what I will have to do is brake down and get new wiring for the front and back lights.I have so many broken and taped wires and some of the light sockets are loose.
Thanks Ron

[spinshop]

Well put the dash harness back in again (for the third time),got a new rear harness and put that in also. Still problems.Unhooked the tail lights and front parking lights to see if that is the problem.Still when I push the cluster into the dash the high beam indicator light lights up and when I turn the key on the temp gage goes to hot .Also when I was plugging in the light for the glove box the wire hit the console and it sparked and blew out the tail light fuse.What could I have done wrong?ANY suggestions would be great.
Thanks Tim