Headlight ground wire?

[69 Cruzin 4]

Where is the headlights grounded on 69 coupe? Running Halogens with RCC relays , refurb harness,  new switch , new dimmer switch . All four lights work on hi but when I dim them nothing works. Thinking it's a bad ground but really not sure what's going on. Thanks

[Midlife 814]

Not a ground issue, but probably a bad dimmer switch or mis-wired relay for the low-beams.  Yes, I know...you said new dimmer switch, but that doesn't mean it isn't bad.

[69volunteer 84]

agreed. Dimmer switches are notorious for being bad. I would try swapping that out first.

 

 

[69 Cruzin 4]

Well I just went back with a new dimmer switch  and still no low beams. Got in touch with Bob at RCCI and we troubleshoot the relays. There is no problem with the installation there. Funny thing is, I tried one of the old incandescent and it worked on low . It was sort of dim but it worked. 

Park lights work just fine.

Dash lights keep blowing a fuse when I turn them on but I assume that's a separate problem. 

I even purchased two new Scott Drake hi/lo halogens thinking that the filament might be blown.

Maybe wrong type of bulbs? Idk.

Thanks

[69RavenConv 286]

Those are the correct bulbs - 13007-A (3-prong) outboard and 13007-B (2-prong) inboard - so that's not your problem.

A couple more things to check:

If the high-beam and ground leads are swapped on the 3-prong connector to the outboard bulb, it will cause the problem you're seeing.

A bad relay on the low beam circuit, try swapping in another one (or swap the high and low relays) and see if the problem persists.

Good luck, electrical problems can be frustrating.

[69 Cruzin 4]

Thankyou, I will sure give that a try in a couple days.

[69 Cruzin 4]

Are the wires in the correct position on the connector?

Thanks

[Midlife 814]

Yes.

It is possible that the spade prongs that fit into the dimmer switch isn't making good contact; check the red/black wire which are the low-beams.

[69 Cruzin 4]

UPDATE: Pulled the red/black wire from dimmer switch and it "looked" good. Cleaned the prong  anyway . Still have nothing. 

Have 15V on the green/black at the harness and 0V on red. 

At headlamp have 12V on green/black and 0 on red

I guess it could be possible that I purchased 2 bad switches??? IDK...

[Midlife 814]

Power comes in on the center (red/orange) wire, and the dimmer switch takes that power and sends it to either the green/black or red/black wire.  Since you have voltage at the green/black wire, press the dimmer switch and see if you now have power at the red/black wire.  If not, the dimmer switch is bad.  

[69 Cruzin 4]

Ok . On high i got powerr o red/ orange and power on green/ black.... nothing on red/ black

On low i got power on  red/orange and power on red/ black..... nothing on green/black 

[Midlife 814]

8 hours ago, 69 Cruzin said:

Ok . On high i got powerr o red/ orange and power on green/ black.... nothing on red/ black

On low i got power on  red/orange and power on red/ black..... nothing on green/black 

That's as it should be.  OK...the problem is not at the dimmer switch.

[69 Cruzin 4]

So I assume it must be the red/blk wire has lost connection at the fuse box or from box to harness correct?  If so how can it be checked? 

Also is there some place that sells a fuse box with the wiring already installed? 

Your help has been much appreciated. 

[Midlife 814]

3 hours ago, 69 Cruzin said:

So I assume it must be the red/blk wire has lost connection at the fuse box or from box to harness correct?  If so how can it be checked? 

Also is there some place that sells a fuse box with the wiring already installed? 

Your help has been much appreciated. 

Yeah, continuity from the dimmer switch through the fuse box junction out to the two headlights must be bad. 

Midlife Harness Restorations sells a fuse box with all of the wiring installed, but it comes with a complete harness.  *G*  No sense replacing a fuse box for a single wire that may or may not have problems at the fuse box. 

After disconnecting the battery, pull the fuse box from the firewall and measure continuity between the red/black at the dimmer switch and the wire at the junction.  It is at the row below the large pin, and fourth from the large pin's location inwards.  The top row has the large pin and 4 pins; the next row has 6 pins.  The third row has offset pins at the beginning of the row.

[69 Cruzin 4]

Ok, think I might be looking in the wrong place for the outage. Went out and replaced halogen with the regularH4 that was originally replaced. It works fine, hi and lo. 

So apparently I've blown the low beam filament twice now. These were $25 bulbs and I've went through 4 ...ugh 

Any idea why I would be popping these bulbs when I turn them on?