1955 Buick Roadmaster Blinkers/Dash lights issue

[buickbrothers]

Hello all. As I've been putting the car back together, I've run into a couple of new issues.

1. Testing the turn signal, my rear taillights are flashing as expected. I wired the front turn signals to the terminal's (they are not mounted to the fenders just hanging) and they are not working. This may be a dumb question, but do they need to be mounted to the fenders to be properly grounded? Bulbs are good and I know the turn signal is working (making contact) based on back lights working.

2. None of my dash lights are working except the red parking brake light. These are all new bulbs. The turn signal lights make a "tick" when I flip the turn signals but don't light up. I only have the lower dash in and not the upper dash that houses the speedometer. Lights that mount to the speedometer are hanging but Gauge Lights are all installed.

 

I've checked all the wires to the fuse panel and they are correct. Is there a ground that runs to the dash somewhere that is missing? I know I need to run some tests on the light switch for the dash lights but this wouldn't explain the front turn signals not working although the back ones do. Thoughts?

 

[Specalist John]

Has to be grounded..I had the same issue when I was putting mine back together also

[KAD36]

Same for the interior turn signal light bulbs that are on the end of those long flat clips that have to be pushed up inside the speedometer or grounded with a test jumper as mentioned above. Same for the speedometer gauges radio clock etc all have to be mounted and grounded through the dash to light.  Assuming the rheostat on the light switch isn’t scratchy and intermittent.

[Specalist John]

When I got my car back from paint. I changed every bulb in the car twice and it was a ground... I  even bought (3) 3 prong flashers. fixed the ground and it was good to go. 

[buickbrothers]

Thank you all for your feedback. It's a relief to hear. I suspected it was related to grounding and all parts not being fully mounted. I'm learning how dependent these old cars are on grounds at multiple mounting points. 

[Specalist John]

Hahahaha.It will make you lose sleep at night

[buickbrothers]

That it did! I did a lot of work to clean-up the entire dash wiring harness that had some melted/bad wires from a short (blower motor) and splice in's where the previous owner added some other accessories (CB and Siren). The car belonged to a Fire Marshall in the 50's. Kept the siren for fun. Thanks again. 

[Specalist John]

No problem...if you needed parts,I have a parts car .56 Buick Century 4dr hardtop 

[buickbrothers]

Thanks John, will keep that in mind!

 

[buickbrothers]

Ok more tests have yielded positive and negative results. Grounded front blinker housings and both are working! Plugged all loose lights into speedometer housing (other lights in gauges are mounted to dash). Still not getting dash lights. I'll try a few more grounding test here as I don't think I'm solid on grounding yet.

 

The two throwing me, that should not be a ground issue, is the trunk light and the back-up lights. The rear taillights function on all tests (blinkers and night lights through the headlight switch). Reverse lights are not coming on. Maybe the neutral safety switch? I grounded the trunk light and still nothing. Thoughts? 

[Frank DuVal]

Neutral safety switch is only in the staring circuit (AFAIK). Oh, you mean the backup lamps, sorry 😟  dolt slap, then yes, jump the back up lamp terminals of the NSS and see if the backup lamps come on. These should have the black and blue wires going to the terminals.

 

Trunk light is a mercury switch inside the socket. It has to be grounded and held at the right angle for the mercury to fall across the internal contacts and make the light come on.

Edited September 16 by Frank DuVal (see edit history)

[JohnD1956]

24 minutes ago, buickbrothers said:

Still not getting dash lights.

Just checking that you have rotated the light knob. If so you can also put a jumper wire across the rheostat terminals on the light switch just to verify the rheostat isn't the problem.

[old-tank]

Dome lights?...trunk light on same fuse.

[buickbrothers]

Interesting, I didn't know the trunk light was a mercury switch. Good to know, and thanks for that information. I don't have the dome lights in yet as the interior is still gutted. I can hook the dome lights up and also check them. Yes, I've turned the light switch knob since they act as a dimmer and also control the map light. I'll try the jumpers. Thanks all, the suggestions are helpful. Crazy question, how can a verify the dash is properly grounded and if it's not, how do I properly ground it? The reason I'm asking is that my fan's (defroster and under seat heater) are also not working. When I flip the fan switches one fan acted like it kicked on for a sec and then nothing. Seems I am fighting ground issues. Here's a pic of the dash before I put the speedometer in to tie all the remaining light in showing in this pic. As stated earlier, I didn't want to put the upper dash piece in until I have verified all wires and vacuum lines are working. As an example, the fan switches are sitting on all the new dash paint - are they not grounding due to the paint? 

 

[JohnD1956]

I believe most switches in these cars simply connect the positive field of electricity and the circuit is completed at the unit being powered. For your dash lights the positive field comes through the light switch and each bulb is grounded when installed in the instrument housing. Since the instrument housing is metal that provides the ground when it is bolted to the metal dashboard frame.  For your fans the switches should energize a rheostat the gives you the various speeds. Then the rheostat energizes the fan motors which are grounded when they are bolted to the fan housing and the housings are bolted to the floor and or firewall. 

 

 

[JohnD1956]

There is an exception to this in the dome and map light system.  Those are powered all the time I think.  And each switch in the system completes the circuit to ground. 

[buickbrothers]

I jumped the neutral safety switches right side two terminals (black and blue wires), and the back-up lights came on. I assume that means the switch is not making contact internally when shifting it into reverse? 

 

I jumped the light switch using terminal 1 to terminal 2,3 and 4 independently. I got nothing on any of the dash lights. I had the rheostat in a mid-point position. However, I believe I read this test is only valid when you have some power to the lights already and if they dim, then the rheostat is bad?

 

New question - how can I test the horn without installing the steering wheel and ring? What do I jumper?          

[Dandy Dave]

Ground out the wire that connects to the steering column that feeds the horn. That completes the circuit.

 

[buickbrothers]

Sorry, guess I should have stated it differently. How do I test the low and high horns directly. I did already ground to the horn wire and got nothing. I know the horn wire, brass collar and horn switch is good as I rebuilt all these when I worked on the steering column. What I'm looking for is a test on the actual horns themselves as I'm not sure they are good. I heard a rattle inside one of them. Here's a pick of the new collar I made to solder the horn wire to on the steering column. 

 

 

[Dandy Dave]

Be sure the horn has a good ground to - and put the power to where the wire attaches to the horn on the plus side of the battery. The horns have vibrating contact points in them. Not uncommon that they are oxidized. Some times it takes a bunch of times connecting and disconnecting to, "wake them up." If you get a spark when you touch the wires usually they will work with a little patients. If you have covers that can be removed then you can access the contacts and clean them.  

Edited September 18 by Dandy Dave (see edit history)

[M1842]

Regarding backup lights, may just need to clean the contacts on the NSS.  I thought mine was bad but after working the shift lever a number of times they started to come on.  Dimly at first, but removed corrosion from thr bulb base and inside of the socket and now they are bright.

[JohnD1956]

4 hours ago, buickbrothers said:

Sorry, guess I should have stated it differently. How do I test the low and high horns directly. I did already ground to the horn wire and got nothing. I know the horn wire, brass collar and horn switch is good as I rebuilt all these when I worked on the steering column. What I'm looking for is a test on the actual horns themselves as I'm not sure they are good. I heard a rattle inside one of them. Here's a pick of the new collar I made to solder the horn wire to on the steering column. 

 

 

Thats a nice collar. Is it soldered to the column though?

[buickbrothers]

Ok, I've made progress. Backup lights are now working. Repositioned the neutral safety switch and that did the trick. Trunk light is now working. Had to remove some paint where light bolts in for a solid ground. Horns are now working. Had to take them apart, clean them, clean points/adjust.

1. Before I close the horn's up, is there some kind of coating I can apply to the inside to keep them from re-rusting?

2. Still evaluating the dash lights. NO big discovery as of yet and hoping it's something simple like grounding. Does every single light need to be mounted for any of them to work? Still poking around. 

 

Thanks for all the help - thrilled that things are working and especially the horns! I put a lot of work into making the brass collar, rebuilding the horn button and wire and adding the missing horn switch.  

 

[buickbrothers]

Sorry John, just saw your note. Yes, horn wire is soldered to the brass collar. 

[buickbrothers]

Any thoughts on a coating to keep them from rusting that won't affect the horns performance?

 

Before:

Before:  

 

After: 

 

 

 

[JohnD1956]

Dielectric grease?

[EmTee]

WD-40

[buickbrothers]

I went with a lite coating of dielectric grease. WD-40 I use more as a cleaner vs. a coating/lubricant since it evaporates. It's great for removing that factory blown on tar/undercoat with a heat gun. Thanks for the inputs.