Author Topic: New electrical harness trouble shooting  (Read 1953 times)

Offline JH27N0B

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New electrical harness trouble shooting
« on: November 05, 2016 - 09:42:43 AM »
I'm pretty ignorant on electrical things.
I've put new M&H headlight, taillight, and engine harnesses in my project.  My dash harness was gone through by a local Mopar electrical guy.
I put a battery in for the first time yesterday and checked things out.  All exterior lights worked except the drivers rear side marker light.  I tried a second new bulb in it, still no luck. Not sure what to do there.
Brake lights don't work either but I'm going to try adjusting the switch before I panic on that.
In the interior, no dome light, instrument light bar, fan or radio.  I checked the dome light, which the resto shop installed, and there is a bulb in it.
Turn signals just stick on right or left.  Parking brake light and key buzzer work.
Pretty sure the battery isn't fully charged.  I have an older charger and didn't want to overcharge, so I think I undercharged instead.  I took it to the parts store yesterday and they said it needed to be charged more before it could be load tested.
So I'm trickle charging again with my antique charger.  I don't have have a hydrometer, I tried to buy one yesterday but neither of the 2 parts stores I went to carried them.  So I ordered one off eBay but don't expect I'll have it until midweek next week.
Anyone have any hints?




Offline Lbs

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Re: New electrical harness trouble shooting
« Reply #1 on: November 05, 2016 - 11:51:23 AM »
I don't know if you have recently painted the car but you need to make sure you have good grounds everywhere they connect to the body. I put new harnesses in my newly painted car and trouble all over the place. I ran a new ground wire from my dash to a ground in my engine compartment and made sure the paint was gone, :faint, where all the other grounds happened. Good luck


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Offline shawge

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Re: New electrical harness trouble shooting
« Reply #2 on: November 05, 2016 - 05:22:43 PM »
 :iagree:
- Jerry

Offline roadman5312

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Re: New electrical harness trouble shooting
« Reply #3 on: November 05, 2016 - 06:16:57 PM »
                          Grounds   

Offline anlauto

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Re: New electrical harness trouble shooting
« Reply #4 on: November 05, 2016 - 07:03:40 PM »
I take a grinder to the new paint where the marker light housing mate to the body of the car inside the fenders and trunk to ensure good grounds for the marker lights.

Is the dome light plugged in, are the instrument light bar, fan or radio plugged in ? A lot of little things can get over looked during assembly. :2cents:

Does the door jamb switch work ?
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Offline JH27N0B

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Re: New electrical harness trouble shooting
« Reply #5 on: November 05, 2016 - 08:29:37 PM »
I'll try grinding a little paint by the one housing.
The shop installed the dome light when they did the headliner.  I saw the plug on the c pillar for it, and recall plugging it in.  As for the door switches, one is one of the originals, which I cleaned up.  Another is a used one I bought that was cleaned up.
The shop installed the dash, so I'll have to check the light bar to make sure it's plugged in.  I wonder where the fan plug is.  I just got the radio back from a vintage radio repair place a week ago, and plugged it in myself when I installed it.
I was wondering about the battery, a yellow cap repro I've had sitting around for years.  I filled it and put it on a charger for while a few weeks ago.  I didn't have a hydrometer to check it, at least I thought I didn't.  Today I stumbled across one in a drawer of miscellaneous tools.  All cells showed full charge except one, which is dead.  Rats!

Offline anlauto

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Re: New electrical harness trouble shooting
« Reply #6 on: November 05, 2016 - 10:19:45 PM »
Are you getting anything from the radio ?  Funny story...For a long time I couldn't figure out why I was only getting static....it wasn't until I drove the car outside of the shop that I was able to pick up an AM station :screwy: :banghead:
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Offline JH27N0B

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Re: New electrical harness trouble shooting
« Reply #7 on: November 06, 2016 - 08:36:34 AM »
With the radio, I wasn't seeing a light.  Radio shop said they replaced several capacitors and the lightbulb, so I'd think it would at least light up if it's getting power.
I wouldn't expect it to get sound yet regardless.  I could see I was going to have to sort out something with the speaker wires.  There were 2 different style connectors on the green wires.  One was a small slide on style, the other had a gray plastic connector with a spade in it.  The NOS dash speaker has 2 spade connectors on it,  the slide on connector on the one lead works fine, but the gray plastic connector wouldn't work with the spade.
I wondered if I'd need to splice a slide on connector on the lead that now has the gray one.

Offline JH27N0B

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Re: New electrical harness trouble shooting
« Reply #8 on: November 07, 2016 - 09:31:48 AM »
I put a good battery in the car yesterday (actually it's a Walmart battery I've been using in my convertible since its repro red cap one went bad, and that was 14 or 15 years ago and that Wally world battery is still going strong!), and tried some things out yesterday.  The fan is working, the IP light bar is working, and when I touched the inop side marker light socket to a taillight stud for a known good ground, it lit up.  So that one is a ground issue, good call on that Allen and others on grounds. That one is easy.
I'd crawled around under the dash the previous evening messing around with the brake light switch on the brake pedal, and my tweeking on the adjustment worked out too, the brake lights are working properly now when you push the brake pedal.
So now I'm just down to no dome light and the radio not working.   Those aren't the end of the world right now, I can sort them out later.
Then we tried to start the car for the first time, and after messing around with it for 15 minutes or so to no avail, I noticed several recesses in the intake manifold were full of gas!  :eek4: Soon figured out the rear carb was leaking, a lot!
After tightening up some screws on the carb, tried it again, the car still didn't start and the rear carb was still leaking a little. Called it a day and will replace some gaskets on that carb and try it again this week!
One of those win some, lose some days..
And to add insult to injury, paint started to peal off the intake manifold where the gas had been.  The resto shop must have used some pretty poor quality engine paint when painting my engine!  :swear:

Offline 1 Wild R/T

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Re: New electrical harness trouble shooting
« Reply #9 on: November 07, 2016 - 10:59:40 AM »
Not meaning to be a smartass but thats a pretty authentic resto... Back in the 70's most cars with Holleys had some missing paint cause the fuel will eat the paint....  And gaskets probably aren't your issue, debris in the fuel inlet needle.... Nice thing about a Holley you can unscrew the needle without removing the float bowl....  count the turn so you can get it back close to where it belongs without allot of trial & error....  Good luck you can't seem to catch a break...
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
RM21H9E 69 Road Runner Coupe R4 Performance Red, Sold...
5H21C  65 Falcon 2 dr Wagon... Dog Hauler...

Offline JH27N0B

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Re: New electrical harness trouble shooting
« Reply #10 on: November 07, 2016 - 11:51:49 AM »
Gas seemed to be leaking from the bowl to carb body area.  All 4 screws attaching the bowl seemed a little loose.  After tightening them up and reinstalling the carb, most of the leaking stopped, but it was still leaking a little.
One of my buddies who was over helping suggested the floats might be adjusted too high.  He said he was going to get some clear inserts for the bowl brass sight hole screw/plugs which he said you can use to set float without ending up with gas flowing out of the holes when you have the plugs removed.
This engine was run on a stand 4+ years ago at the rebuilder.  However, it wasn't painted until it went to the restoration shop that finished the body work and painted the car.  They had to remove the carbs and distributor etc to paint the engine, and the engine hasn't been run since they did that.
I'd contacted the rebuilder last week, and he warned me to watch the carb gaskets, after sitting for 4 years they could end up leaking when fuel flowed in them again.  And he was right, about one of the 3 carbs...

Offline JH27N0B

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Re: New electrical harness trouble shooting
« Reply #11 on: November 12, 2016 - 11:07:46 AM »
Gas leak is fixed.  My engine builder suggested putting some bearing grease on the threads of the fuel line fittings, then tightening everything up.  The fittings take a set when you install, and if you remove and reinstall you can get hung up on a ridge and think you are tight, but not.  The grease lubes to get over the hangup.
Got the engine fired yesterday!  Fuel lines now dry as a bone!
Sadly I have another electrical issue.  No charge.  I have an NOS alternator, there is an automotive electrical place 1 mile up the road from me and I never bothered in all the years that alternator sat on my shelf to take it there to have them test!   :banghead:  I did scrape paint off the voltage regulator and firewall to help assure it's grounded when I installed it.  Anything else I can check or is it most likely the alternator?

Offline 1 Wild R/T

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Re: New electrical harness trouble shooting
« Reply #12 on: November 12, 2016 - 12:33:31 PM »
Test for 12v at the blue wire going into the alternator with the key on, if you have 12v took the wire back up & try pulling the two wire plug off the regulator, ground the green wire, engine running the alternator should charge...  If it charges there are a few more tests but suspect the regulator...
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
RM21H9E 69 Road Runner Coupe R4 Performance Red, Sold...
5H21C  65 Falcon 2 dr Wagon... Dog Hauler...

Offline JH27N0B

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Re: New electrical harness trouble shooting
« Reply #13 on: November 12, 2016 - 10:15:46 PM »
Thanks Randy, will try those checks out and see what I find.