Garage Door Opener Won't Work in My '67 With Engine Running

[Brooks G.]

Hi guys! Several weeks ago I posted a thread about the problem I was having with my '67 Corvette. With the engine running my garage door opener would not work. I had to step about 10 feet away for it to do so. I thought the problem was with my alternator. I unplugged it and the opener worked. At that time I was also replacing the radio with one that has bluetooth. Well, the radio would not work with the engine running either. I have radio suppression ignition wires and full ignition shielding. I tried various things including replacing the alternator which was giving me trouble anyway. Nothing worked. I talked with a friend of mine who talked with a restorer in Jackson, Tennessee who came up with the solution. First let me say that I am not any kind of electronic or electrical genius. I can't explain the why with the solution only what worked. My understanding was that my car has some kind of problem referred to as radio frequency interference or feedback. I don't know if all cars have it but mine does. The solution was to run a wire from the hot lead going into the radio to the fuse box. I do not have power windows so I was able to plug into one of the two leads there. Both leads worked to make the radio play and the garage door opener operate. I had to use the left lead as when plugged into the right side lead on power windows caused some of the dash lights to come on. Now everything works as it should. I don't know if the new radio had anything to do with it or not. It looks original but sounds far better than any factory radio from back in the day did. I hope this will help someone with their project. Thanks in advance for your input.
Brooks Glover Jr. (2141)

[Bill M.]

Re: Garage Door Opener Won't Work in My '67 With Engine Running

i could understand the doorr not opening to let the car in! the car wants to stay out and have more fun !!

[Mark F.]

Re: Garage Door Opener Won't Work in My '67 With Engine Running

...Point #1: My understanding was that my car has some kind of problem referred to as radio frequency interference or feedback. I don't know if all cars have it but mine does.

Point #2: The solution was to run a wire from the hot lead going into the radio to the fuse box....

Regarding Point #1:motorsradio waves.
Sources: NASA and http://www.gohz.com/why-motor-produces-emi

An automotive alternator is an electric motor wired to produce current rather than consume it.
Source: https://hackaday.com/2020/01/16/car-...ors-heres-how/

https://www.youtube.com/watch?v=rQy-hIMY__A

Regarding Point #2: Could not find anything sensible to explain that. I wonder

[Rich G.]

[Mark F.]

Re: Garage Door Opener Won't Work in My '67 With Engine Running

Huh...probably the good 'ole inverse square law at work...many energy-emitting sources (devices) follow an inversely proportional relationship to the square of the distance from the source of that physical energy-emitting device. IOW, double the distance from the source and the energy delivered at that farther distance is 1/4^th the intensity of the original source. Triple the distance and the energy delivered at that distance is 1/9^th

[Richard M.]

Re: Garage Door Opener Won't Work in My '67 With Engine Running

I'm thinking the Corvette, with its fiberglass body, is allowing more RFI from the ignition system and is outside the suppression range on that model opener. The opener may be more sensitive to the effects than a metal bodied car, thus causing the problems. It's also possible that when the opener manufacturer performed their testing that they never considered a fiberglass bodied car in their compatibility testing.

Another possibility adding to the anomoly is that several or all of the U69 radio noise suppression condensors on the car are now defective due to age, or missing. Ground straps and clean solid connections are also related to reduce effects. Are the radio cases solidly grounded or do the simply have a small gauge Black wire in the harness for their ground.

Do these cars have their distributor and spark plug/wire shielding in place? If not, this could exacerbate the issues as well. Are these conventional points ignition, K66(TI), or aftermarket electronic?

Running a power wire from Bat+ at the fuse panel may reduce RFI simply because of it's direct path and proximity to the grounded metal dash crossbrace too.

Many factors to consider.

Rich

[Gary C.]

Re: Garage Door Opener Won't Work in My '67 With Engine Running

Brooks,

Rich pretty well summed it up, as there are many potential problems that exist in a C2 wiring such as bad grounds, bad connections, etc. etc.

Corvette experience has taught me to always start with the basics; good solid ground; i.e. running a wire from the component directly to the negative battery terminal and the power source by running a fused power lead to the component such as the radio, directly from the positive battery terminal.

RFI is prominent everywhere. Some devices such as a remote garage door opener probably lack in other source RFI shielding and might be confirmed by holding the remote garage door opening up high and using an aluminum pan under it as a RFI shield.

Glad you've got your problem solved.

Gary
....

[Frank D.]

Re: Garage Door Opener Won't Work in My '67 With Engine Running

A bit off topic, but I put this on my garage door for $30 and can open/close garage door from any vehicle with voice commands or the phone app from anywhere:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

You can put a "widget" button on your smart phone to make it work just like a remote; with a little coding you can open the door automatically as you approach your home via geo-fencing. You can check your garage door status (opened/closed) from anywhere and get notified if ithere is an unauthorized opening (car theives). 1/2 hour installation time. It requires wifi in your garage however RF not needed, so no interference.

[Brooks G.]

Re: Garage Door Opener Won't Work in My '67 With Engine Running

Hi Guys, sorry but I have been out of pocket. Thanks for all the replies to my problem. I guess I forgot to mention that in 2017 that a new wiring harness was installed in my car. Of course all of the grounds were checked to make sure they were good. Unplugging the alternator made the problem go away but I did not want to drive around without one. The addition of the wire from the hot lead going into the radio to the fuse panel has solved my problem. With this wire in place now the radio plays and the garage door opener functions as it should with the engine running. I thank everyone for their input. I only hope this post will help someone else. Many thanks! Brooks Glover Jr. (2141)

[Duke W.]

Re: Garage Door Opener Won't Work in My '67 With Engine Running

Back when I first got a digital TV circa 2008 (no cable or satellite just a couple of indoor antennas, one VHF, one UHF) and got the antennas dialed in I had a pretty good signal, but occasionally there was a momentary dropout that I couldn't figure out.

After more time and thought than I'm willing to admit I figured it out... cars driving by, not all, but just some. It's a residential street with little traffic, and these for the most part were modern cars that have to meet federal RFI emission standards.

I'm sure a vintage Corvette, even with all the radio shielding and grounds intact emits more RFI than a modern car, so I'm not surprised that some garage door openers won't function properly with the engine running.

If you can choose different frequencies you might find one that works or maybe rig up a better antenna on the receiver.

Duke