JCMC64

71 Cutlass S in middle of restore.
Front cap is off, both bumpers off, Dash is completely out, steering column down to turn signal cam, Wiring is in front to back but no headlights or turn signals connected.

I want to start checking everything electrical, without installing dash yet. I know there are grounds to connect everywhere. What do I have to install minimumally to check lights, T\L's, Turn signals, flashers, etc. thx.

Current state.

gearheads78

Only way to know for sure is hook everything up and check it.

JCMC64

That is why I said "minimumally" as I dont want to put dash cluster section back in, gauges, etc, etc. unless you have to to make it work.

You didnt put much thought into that answer, eh?! Thx anyways.

gearheads78

I told you exactly what you need to do. I didn't say you had to put the dash in but you still have to check every circuit that you want to know works. That means the dash harness has to be connected to the firewall pass through and fuse box. The column has to be all plugged in. The switches have to be connected. The starter cables and battery cables have to be connected, you have to ground all the bulb connections ect. There is no real short cuts. You can have harnesses temporarily ran out side of components for easy access you still have to "hook everything up and check it"

JCMC64

Read my original post. I said all harnesses front to back already installed.

JCMC64

Actually, you gave no details at all in first post. Not looking for argument, just need answers. Read my original post. I said all harnesses front to back already installed. So I just need to plug in T/Ls and HLs. But I still need to know what is necessary in the dash... Do the gauges HAVE to be hooked up to check turn signals? ... what grounds overall are mandatory to check the TS, HLs and TLs? Do I have to reground the headlight switch again like it is when dash is in to get basic light functions? Need questions like this answered. Also can the HLs work without TLs hooked up? And vice versa? This is also to anyone out there who'd like to chime in.

JCMC64

Answering from my phone and hit submit reply by mistake in middle of typing. That's why 9:43am response was a mess. Fixed it.

gearheads78

Yes I did read your post and looked at your pictures. short of someone coming over and doing it for you there was not much else to say. You don't have to have the gauges pluged in and you can test the front without having the rear harness plugged in. The lights will all have to be grounded. The switch does not. You just have to picuture in your head what it takes to complete each circuit and the direction of flow. Power in - through a switch- to the load (bulb)- and to the ground. A break in any of it and no light.
You might want to get a shop manual with schematics to help you. I just finished rebuilding a whole harness for my 68 and the manual was a big help.

joe_padavano

Plug in the ignition switch, headlight switch, turn signal switch, dimmer switch, and the brake light switch. This will allow you to test all exterior lights. The dimmer is needed to get the headlights to work. The turn signal is needed to get the brake lights to work. The ignition switch is needed to test the turn signals. None of these switches have ground point you need to worry about at the moment. I'm assuming you do have all the exterior light sockets in place and grounded - the tail lights ground through the back bumper, for example. You'll need the dash wired up to test the interior lights.

Sampson

Just my opinion but it would be so much easier after the lights etc are back where they are supposed to be. What is the advantage do jumping ahead to check this now?

m371961

Connect the switches Joe said. You can check with a test light or meter for voltage at lamp plugs and sockets and worry about their grounds later. You can also check for dash light voltage at the cluster plugs.
It will help greatly if you have and can read the electrical schematic.
This is a good time to clean all plugs, connectors and fuse panel.
I would not leave a battery connected with the car unattended, and be able to disconnect it quickly.

JCMC64

Thx to all for the replies.

Joe- Thx. That info is exactly what I was looking for.

Sampson - one of the reason is because its a royal PITA to t\s electrical issues when everything in Dash is all hooked up again. Dont know if youve ever taken out a dash, but everything is brittle, and no room to work, hot, thousand cuss words, etc.
I liked to verify it all first 100%. I got new engine\ Front Lght\ intermed harnesses, better tail light harness than what came with car and want to know everything is working perfect before going through the headaches after putting it all together again if something aint working right (I also had a few issues before the tear down).

M3- Yes I got the schematics printed out and in car. Also got the Fuse charts, light bulb charts, Fuse box guide (half the stencils are completely faded...any suggestions on how to relabel them again anyone?)...so Im good there. And yes, Ive cleaned out all the Fuse box connectors, putting all correct AGC and SFE fuses with right amperage, and using electrical contact cleaner\ 300 grit sand paper on connectors, etc etc.

And yes I disconnect battery every time Im done, or not working on wiring or starting engine, etc. Thx for the help \ Suggestions.

I'll post back my results.

JCMC64

I will be editing this same post as I go through the electrical system.

So far:

1) Got the headlights working. I only hooked up headlight switch and dimmer so far. I checked voltage at the HL plug first using volt meter- good 12vdc. Hooked up headlight, and ran temp ground to alt casing. Lights came on good. High Beams work. So you can check HLs without dash, gauges, side markers, etc. hooked up. Just need to ground front light harness... as Joe\Gears said.

2) Hooked up a front turn signal. Grounded the side marker light to alt casing which its ground runs to turn signal. I get 12 vdc at TS cnx when turn signal is actuated, with ign in run, but no light at the turn signal. If I ground the TS case, I get constant light on. Voltage is not blinking. I got flasher hooked up. I get good 12vdc at the turn signal cnx but when put bulb in, no light....unless I ground the TS case, then it stays on all the time. Turn signals are definitely unique to test.

joe_padavano

You need both front and rear TS hooked up and properly grounded. If you only have the fronts connected, the system is acting as if the rear bulb is burned out, which causes the system not to flash.

JCMC64

OK Joe. Thx.

Do I need to have all side marker lightbulbs installed...Back up lights. etc to check front TS?