Electrical gremlins

[fy469rtse]

Put power in my car for the first time today , who knows how long since this car has been                                    went through main harness and repaired replaced any bad wires, all front harness are new ,
So far have the following systems that work
Interior lights including dome , dash light , dimmer switch will also turn these on , glove box light works as well ,
Have reverse lights , trunk light , wipers 3speed , heater fan functions 3 speeds
Headlights low and high beam , these have been relayed ,
Turn signals front and rear,
have stopped here because of the following faults and hoping the knowledge on here will point me in the right directions,
Turn key on to acc on to the run position , noticed there's no movement to gauges, also the dash lights are not working, this has a brand new modern voltage resisted curcuit board from charger speciality s
Tail and brake lights don't function, keeps blowing the fuse, before I get a chance to test brake lights, they work before fuse blows, put a new fuse in and this shortly blows as well
Hazard lights don't function either , I thought these might work as indicators function,
Where to start ? What would you guys suggest I start with , want to sort these issues as I find them , sort this lot out and move on to the next lot

[don duick]

don't know about gauges and dash lights but I had exact same problem with brake lights. you may have a problem with your blinker switch. The brake lights are activated by the white wire from your blinker switch, remove and check this switch, In my case what happened was the white wire got wedged under the plastic casing and shorted on the steering column. the white wire from the blinker switch connects to the brake light switch on your pedal the other 2 wires, one of which is pink, is connected to your interior dome light which  provides the power for your brake lights..

[Pete in NH]

Hi,

I would put a 20 or 30 amp fuse in series with either one of the battery cables while you are doing your initial testing and have a box or two of spares. This would keep any potential wiring problems from causing any real damage.

I think Don has given you a good starting point for the brake light issues. Everything goes through the turn signal switch. Although, it could be a short circuit from a wire caught under sheet metal as well.

On the gauges, I suspect you may not be getting power to the new voltage regulator for the gauges on the dash printed circuit board assembly. You should be able to see a pulsing voltage or steady 5 volts between any of the sending unit wires and ground. For example, pull off the temperature ending unit wire and measure between there and ground. It depends on how that new voltage regulator operates whether you will see pulsing or a steady 5 volts. If you can get a 27 ohm resistor from Radio Shack or a local electronics supplier and connect it between any gauge sender wire and ground the gauge should read about mid scale.

One approach for others rewiring their car that I would use is to hook up one thing at a time and check its operation. Then repair if required before moving on to the next. That way you keep things from piling up on you.

[fy469rtse]

thanks Guy's for replying,
good starting points,
i have a new switch, might start there tonight , will keep you posted 

[fy469rtse]

Some suscess tonight, checked through horn switch, that checked out all ok ,
Was blowing the fuse continually, to tail lights , so just unplugged everything to this circuit in the hope it would highlight the area. Plugged everything in one at a time until it blew the fuse , found a combination of things , one I created , missed certain things about my 68 , side clearance lights, so fitted some , no ones noticed but I like the way they look when lit up, I had a couple of wires back to front, still blew fuse , ok multi meter out now , found bad earth , still blew , got it to the rear globes , isolated problem to that area,
With right indicators on back globes strobed , had a bad globe holder baker light material at fault , changed that out, I was amazed that I had at some time bought new spare globe holders with baker light , springs and new wire pins ,
Wouldn't even know we're to look for these now ,
Next to test if I have brake lights
No hazard lights , will check first the flasher unit ,

[redmist]

When you activate the flasher lights, are you setting the blinker on in one direction or the other?? I believe you have to do this to get them to work as the flashers and the blinkers use the same flasher bulb if I remember correctly.

Turn on E-Flashers, and set your turn indicator right or left, and see what happens.

[fy469rtse]

thanks Redmist ,
no they have two seperate flashers for this purpose , cant get any function here , so guessing a bad switch,
have dash cluster out investigating dash light gauge function issue, power to harness , just nothing works lights up, no function at gauges,

[fy469rtse]

Got some life out of my dash tonight, new circuit board had some questionable looking solder ,
Got my pencil solder iron out went over these , also put some solder to what appeared to be a line or break in on board path, just happened to be main feed track on board ,
Put everything back to test it
Lights , my dimmer switch that I rebuilt myself works a treat, now back to hazard lights , ?

[Pete in NH]

Hi,

Sounds like your making some progress. On repairing the break in the main board feed track, you might want to actually bridge the break with a piece of wire soldered to each end of the break. Bridging the break with solder alone might break again if the board flexes. For a new board assembly it sounds like it had some quality control issues.

[Dino]

Seeing you have hazzard and brake light issues, I'd check the turn signal switch and the connector under the steering column and the one under the driver's side kick panel.

[fy469rtse]

Thanks Pete NH , good advise , I think I will redo that ,
Lights , dimmer work , but should gauges show readiness once key turned on, pulse up to zero ?
Got brake lights working, brand new switch , just junk , waiting on the new one , hazard lights are a different issue ?
Can't seem to find the fault with these ,
Been studying the wiring diagram trying to understand how which wires make in function,  bad flasher unit , would I look for in specs to try replacement unit , although this was new old stock, but I may have the wrong one
Have power to one side of plug here , everything seems to cross paths , on diagram
Thanks Dino
New stock replacement plugs and contacts when going through wiring , but I did double check those

[Pete in NH]

Yes, the gauges should show signs of life as soon as you turn the key to the run position. To check this out use that 27 ohm resistor I mentioned earlier to replace the temperature gauge sending unit. The gauge should go up to half scale.

[fy469rtse]

Thanks pete nh ,
going to pick up a resistor tonight and see what response i get out of temp guage,
do you know off hand resistance values on fuel gauge , oil , can i test these the same way

[Dino]

Yes you can test all the small gauges this way.  73 ohm for the low reading, 10 for the high, 27 for middle.  This is not an exact science but you can get them very close with these values.  To calibrate my fuel gauge I used resistors first, then hooked it up to the fuel sending unit and poured 5 gallons in the tank. I bent the float slightly to make the guage read one quarter full.  I added 5 more and the gauge read a tad over half.  With a full tank the needle reads just past the full mark and with the needle on empty Ihave about a gallon left.  Can't ask for more! 

[fy469rtse]

That's a good tip Dino, was worried about that because I bought my sending unit back a while ago, and it's probably one of those that don't read right,
You have the fix for everyone
By passed the hazard switch tonight to hard wire the function , worked ,
now what ? who do you guys use to rebuild switches,
is it hard , what's needed, die electric grease ,
mind you this was most of the nights work dropping column slightly and to get cluster out and test switch , a/c cars are a pain with all the extra crap under and in dash 
Horns are next, relay's live jumping them there makes them sound ,
new boss steering wheel , what did I miss regarding earth contact in column,
went to a lot of trouble to make sure this was new and not grubby contacts ,
single roller earth contact to brass contact , wire up through column to horn swith, to complete this circuit ,
Eliminated area's to where the trouble spot is, simply run a jumper earth at bulk head plug, horn's sounded, this didn't work at column plug , earth strap to column,
To body of column and one column attaching stud correct ?

[Dino]

That sounds about right.  If it works by grounding the system but the horn button doesn't work, then it's not completing the circuit somehow.

If the fuel sending unit is new then you can't get the gauge to read right.  I cut off the resistor part on my new unit and welded the one from my old unit on.  I went from the smaller one to the larger one with return line.  All I had to do was bend the float arm ever so slightly to make it read right.  It's a joy to finally have all the gauges work as they should, especially the fuel gauge.   

[fy469rtse]

 Re soldered break in circuit board ,
Have lights to dash
Opened up switch , very simple inside , movable contacts , spring , baker light board with contacts
Anyway cleaned up , stretched spring a little, tapped rivets tighter on wire pins , some die electric grease ,
And what do you know , they work ,

[Dino]

    

[TylerCharger69]

  Another thing that happened to me. I had brake light/turn signal issues too.  Come to find out, after brushing up on my four letter words, there is a skinny piece of stainless trim that goes from the kick panel toward the back seat along the carpet on the floor. This is where the wiring harness goes underneath the carpet on the driver side. That small skinny piece...well the screw that holds it down pierced the wire. It took me months to find it. Maybe a heads up to anyone who has done this.....Surely I'm not the first one this has happened to???

[fy469rtse]

dont worry , tylercharger69,
do you know what i have been doing since last post, when i went through wiring renewing everything, i had ordered new bulk head plug and connectors, realised i hadn't fitted that and renewed 40 plus years old connectors, not there that bad , just the plastic bulk head connector has seen better days, and i'm not leaving anything to chance
when i was mocking everything up in place , put this in the firewall and forgot it , came across the new one in parts box's and realised i'd forgot it

[fy469rtse]

Latest update very frustrated,
Posted that I had forgotten to put the new bulk head in place , all of you that have worked on these cars will know how difficult to get this out , ac car
New pins replaced one wire at a time to new plug, got it all back together, no turn signals, hazards work and horn, pulled it all back out just to check against wiring diagram, to make sure all were in the right spots
Odd thing is the left hood signal won't flash with hazards on , all else works , just no turn signals ,
Turn signals were working before I did this , what the #%£€ did I upset , have checked all plugs and contacts,
Earlier you guys had suggested tun signal switch, have ordered this just in case,
Walked away tonight very frustrated,
I had dropped column for access in to dash, I didn't forget the column earth strap,
I had to half pull it back apart because I had bumped one of the wiper arm links off , so two jobs in one
Now just just don't know where to go from here , I will wait for turn switch to turn up and see what happens from there unless any suggestions guys

[Dino]

Sory to hear about your troubles, I know it all too well.  After replacing my turn signal switch it solved most of the issues, but the driver's side hood signal would not work and the indicators on the dash would pulsate from time to time.  That turned out to be a bad ground on the hood signal.  Sothe hazards work but no turn signals, aren't those operated by seperate bxes?  There's one to the left and one to the right of the steering column.  Remove each and test them out to make sure there are no issues there.

I've had that bulkhead connector in and out several times, on an a/c car, that was no fun at all!  Especially since I mounted a maxi fuse holder right above it so I had to remove that a few times to reach the connector clips to push it out of the firewall.   

[fy469rtse]

thanks Dino,
yes new digital flasher units, because i converted everything to led's ,
swapped these over just in case i somehow damaged one , at least i found the cause of my hazard lights not working correctly, must have been a bad connection in bulk head plug ,
they work great, had cluster out to check all plugs on switches

[fy469rtse]

Ok found 1 big problem ,
It's now a must for any off you restoring or going through your old loom , found a bad power splice, ok repaired that ,
Re wrapped in tape,
I have a new turn signal switch on the way. But
Getting impatient , so I had I look at old turn signal switch , ok apart from being cruddy,
The blinker cam area appeared to be warped or bowed , took it apart , yes definitely bowed from age, cleaned up all the crud , then contacts , this part is important because of the low draw from LEDs
Clamped some spacers on this to bow it the other way , got my heat gun out and applied some heat until it appeared to bow on its own , quickly clamped this part flat and left it to cool
Re pinned all contacts and polished these up,
Put it back together and hooked everything up, yes I know new switch on the way, ? But if this works eliminates I problematic area , and I can swap switches later
Bingo everything functions as it should hazards indicators horn all good , now for the next thing,  gauges ?

[green69rt]

Hey Geoff, sounds like you're having lots of fun..   Working on old electrical systems will test your patience.  Keep on chipping away.