headlight motor relay upgrade for 1970 & up

[jlatessa]

Search for "Topher", he has the plastic gears as a kit, also rebuilds the whole schmear if you run out of patience.

Joe

[jascharger]

I found a couple of bosch relays on ebay but I don't know if they are the proper ones. Does this relay ,you guys have used,have a part number or code on it?
Any help as always,is greatly appreciated!

[73charger440]

Question I wired my haidaways up and they just go up and when the wires on the motor are reversed it powers the doors in the other direction. My question is do you need two relays one for up and one fore down?

[fizz]

no. the relay should have a normally open terminal and a normally closed terminal. So when you apply power from the switch to the relay it will power up one terminal on the relay. when you cut power from the switch it will power the first one down and power up the other. The switching on the motor cuts the power when the doors are in the full up position and the full down position.

[73charger440]

Mine don't seem to shut off just hummes when it gets to the end of its travel

[70sixpkrt]

If you are using a new wiring harness, they have the wires crossed. Just cut the harness at the clip and switch them around. I bought a new harness years ago and found that out the hard way. Topher sells new units. I bought one from him and works good.

[73charger440]

Yeah I don't have a harness at all but with five wires. I figured with 5 wires I could make my own

[73charger440]

It's a 73 so nothing I have will work

[__Larsson____]

I have done this conversion to my 70 Charger no but i get 12 in both wires to the motorn when the light switch is on. But nothing when its of. 

[AKcharger]

I have done this conversion to my 70 Charger no but i get 12 in both wires to the motorn when the light switch is on. But nothing when its of. 

That doesn't sound wrong

[Derwud]

Just going through this thread again.. Couple of things.

1) get you relay power from the wire that goes from the switch to the dimmer.
2) you should only have power to one side of the connector at the the motor at a time, if not, you have a wiring issue..

[b5blue]

  The 70 HL motor is grounded at the tang by the gearing housing and the dual plug is each 12+ for up and down. (The motor goes one way then reverses.) The switches inside set limit of travel and ready for reversal of action.
  Remember if you run the motor without being installed you may shear off plastic gears inside!

[71charger_fan]

Bumping back to top so I can find it easier when I get a chance to look at it on my computer instead of my phone.

[71charger_fan]

My motor opens the headlight doors, but they remain open when the switch is turned off. I think my relay has gone bad as I have current at the "open" connection at the motor whether the headlight switch is on or off. I had a spare relay, but it didn't test. So, I opened it up and any mystery as to why it didn't work instantly disappeared. Looking at how it's constructed, how does the signal from the green wire into the relay ground? Is it supposed to ground to the case? After I cleaned the rust out of the spare relay and filed the points, I hooked up a hot lead to where the green wire goes and grounded it directly at the top of the coil and the electromagnet works fine. However, it doesn't work with the case back on and hooked up. It's got to be a lack of ground for the signal, but I can't think of how this thing is supposed to ground unless the solder connection at the top of the coil is supposed to touch the outer case.

[b5blue]

Feedback loop through the lights?

[71charger_fan]

I thought about that, but wouldn't the signal current have to be isolated from the load current? I have a plastic case Bosch-style relay that I can swap in, but I'd prefer to have an original if I can make it work. I've considered the '65 Buick Riviera relay for those headlight doors, which are still available new (and cheap). However, I find the wiring diagram for that very confusing. I'll probably just wind up with the Bosch style and call it done.

[b5blue]

Ground isn't broken during switching. A "single throw dual pole relay" switches in an ether/or fashion as opposed to just off or on. I made one work from Radio Shack, it looked insane but worked. You are basically putting 12V+ to up or down (The 2 prong plug.) with ground on the tang attached to the gear head.   

[b5blue]

This will do the job, you just adapt your harness. https://www.opgi.com/riviera/L240177/   Click on the pic and look closely at the relay's side. It is a wire diagram to follow.

[71charger_fan]

I already have a 5-pin relay to put in. I'm still curious as to how the factory relay completes the circuit for the signal current when you turn the lights on since the the factory relay only has four terminals. The signal current comes in through the threaded stud to the thin wire that makes up the windings and seems to end at the soldered connection at the top of the coil. The load current comes in from the circuit breaker at the side of the relay and goes up the heavy frame next to the coil then across the "bridge" part above the coil, through the points and down one of the two legs and out either the "open" or "close" lug. If I ground the signal current at the solder connection it works perfectly, so the relay seems to work. The coil part rides on a plastic bed to electrically isolate it from the load current. When it's put together, it doesn't work. The case had heavy corrosion built up inside of it which I've sanded out. This is what makes me wonder if that solder joint originally grounded to the side of the case. That would allow the case itself to act as the fifth terminal and ground the signal circuit.

[71charger_fan]

I spent a few minutes looking at the '65 Buick wiring diagram. It was a little confusing at first as Buick used two relays. The auxiliary relay makes sure all power is cut to the motor when the key is off. But the headlamp door relay is still available for less than $10 from Rock Auto as Standard RY8. The wiring is almost identical to the '71 Charger relay. Switching at #4, main power at #1 and motor open/close at #2 and #3. According to the wiring diagram on the relay itself, the switching circuit grounds through the case. I'm going to order one of those and give it a try.

https://smile.amazon.com/Standard-Motor-Products-RY8-Relay/dp/B000C7YD1I/ref=sr_1_1?keywords=ry8&qid=1566062061&s=gateway&sr=8-1

[b5blue]

Yup ether this or that terminal. 

[71charger_fan]

Today, I wasted a great deal of time getting the old rusty relay to work. I measured out where the solder connection on the coil was in relation to the outer case and tried knocking the case in at that spot to ground the signal circuit. That actually worked, but not consistently. Plus, if I knocked it a little too far, it would short the main power circuit going to the motor. So, I drilled a hole in the case and put in a #10-32 screw exactly where the solder joint is. I turned the screw in just far enough to exert a little pressure on the solder joint. That worked perfectly. But, as I had no faith in that being a viable long-term fix, I went ahead and (temporarily) wired in a Bosch-style relay just to get things working. I'll replace that with the Buick relay when that comes. Should be here Tuesday. Now, I have to figure out why my dome light never goes out.

[71charger_fan]

Here's the headlight door relay for the Buick. I rigged up some temporary wiring and it works like a charm. $12.27 for a Riviera relay and having to add/change a couple of terminals beats what I've seen for asking prices on NOS relays. You will need one oddball female terminal for the double wire on the ignition run circuit. Or, put a ring terminal on a jumper wire with a single Packard 56 female on the other end. Then bolt the existing ignition run terminal to the jumper ring terminal and tape it well. Plus, you'll want to cut off the ring terminal on the green signal wire from the HL switch and replace that with a female Packard 56 or just an insulated female .25 terminal.

The green signal/switching circuit grounds through the case.

[b5blue]

 

[71charger_fan]

Buick Riviera relay with proper Delphi/Aptiv connectors on the wires.