How to test a power antenna?

[MrEarl]

Will be offering this for sale so need to ensure it works as should. I’m thinking to attach a positive wire from a battery to the center screw of the switch and a negative wire from a battery to the braided ground wire?
 

 

 

 

 

[Ben Bruce aka First Born]

Surprised Barney has not chimed in.

 

  Ben

[Fr. Buick]

Put power to the middle tab on the switch, and ground to the ground wire on the wiring harness.

[MrEarl]

1 hour ago, Fr. Buick said:

Put power to the middle tab on the switch, and ground to the ground wire on the wiring harness.

 

 

Thanks Monsignor, tha's what I thought but certainly didn't want to burn anything up. 

[NailheadBob]

1 hour ago, Fr. Buick said:

Put power to the middle tab on the switch, and ground to the ground wire on the wiring harness.

MrEarl is it alive?

 

Bob

[MrEarl]

1 minute ago, NailheadBob said:

MrEarl is it alive?

 

Bob

Checking today, will report back.

[Barney Eaton]

Sorry just saw this post,  I am at my daughters and do not get on the internet as often. 

Almost all the early power antenna work the same.    The housing needs to be grounded and there will be two wires coming

from the unit.   

You can bench test by using a battery charger... ground the housing and touch 12V (or 6V if very early) to one wire.  

I am thinking white wire is UP and black wire is Down but just touch one and if nothing happens touch the other.

Just for testing I would not worry about using a switch.   If you are going to use a switch as the permanent method of operation, use 

a switch that you must hold in the UP or Down position so that you do not forget it is on and burn up the windings. 

Lamar did not mention but the unit pictured is a early power antenna...'54 -'60  they used that coil of tubing for cord storage. 

In '61 or '62 the design changed and the cord that pushes the mast up was stored inside the unit and do not have that outside 

tubing. 

[MrEarl]

22 minutes ago, Barney Eaton said:

Sorry just saw this post,  I am at my daughters and do not get on the internet as often. 

Almost all the early power antenna work the same.    The housing needs to be grounded and there will be two wires coming

from the unit.   

You can bench test by using a battery charger... ground the housing and touch 12V (or 6V if very early) to one wire.  

I am thinking white wire is UP and black wire is Down but just touch one and if nothing happens touch the other.

Just for testing I would not worry about using a switch.   If you are going to use a switch as the permanent method of operation, use 

a switch that you must hold in the UP or Down position so that you do not forget it is on and burn up the windings. 

Lamar did not mention but the unit pictured is a early power antenna...'54 -'60  they used that coil of tubing for cord storage. 

In '61 or '62 the design changed and the cord that pushes the mast up was stored inside the unit and do not have that outside 

tubing. 

So noted Barney, thanks! The switch feels good, with auto return to the middle position. I'll probably test by hooking up to the switch to ensure there is no problem with the switch. Pretty sure this is a 54-56, but can you tell me what years it may be "correct" for, for purpose of advertising for sale? 

Edited November 9, 2022 by MrEarl (see edit history)

[lancemb]

12 hours ago, MrEarl said:

So noted Barney, thanks! The switch feels good, with auto return to the middle position. I'll probably test by hooking up to the switch to ensure there is no problem with the switch. Pretty sure this is a 54-56, but can you tell me what years it may be "correct" for, for purpose of advertising for sale? 

54-57 - they switched mid year 57 to the reel type.  Every 57 I've had or pulled one out of had this style, but others have had the opposite experience.  I have interest in buying this. 

[Barney Eaton]

When I get home,  I will post pictures of different early antenna and maybe the year experts can tell us what year this is. 

I have some parts for them but have never repaired one because I never have a part that is needed. 

[Fr. Buick]

It looks correct for a 54 at least to me...

[MrEarl]

It is ALIVE

 

 

[dship]

That antenna has got to be 6' fully extended!!!

[Barney Eaton]

Here is a little history that I have on power antenna used on GM cars.   

The unit pictured by Mr Earl is early as there was a 6v and 12v version. 

They used the pinch roll system to push and pull the plastic cord.  

 

The next version may have only been used on Cadillac and it did not have the external tube that stored the plastic cord. 

It also allowed them to index the motor in reference to the mast for under the fender clearance. 

The  picture with the years has a mix.. the top one is the pinch roll version,  the middle is like the second picture (Cadillac) but motor indexed up. 

The bottom picture is a '77 - '79 Delco only used 2-3 years

The three similar units are 1962 - 1978 are made by Tenna and used by GM on all their cars.  The fender mount and length changed for different GM models. 

You can also see that there is a right and left version...note the black plastic motor cover is on the right of the two units on the right but the one on the left 

the motor cover is on the left.    

* Near the end of that production run,  Tenna offered a "automatic" antenna that would extend and retract when the radio was turned on and off. 

the picture with the red background shows two Tenna units...the one at the top is the standard and the botton one is the automatic...note it has 

a large cover on the end opposite the motor to house the switches and cams that made it work.

* Next came the 77-79 Delco mentioned earlier..... it also had cams and leaf contacts that had to be timed...it had a non-adjustible clutch that is a problem

and I avoid working on them. (unit with the red gear) 

* Finally around 1979 the Delco Slimline first appeared....the early versions had a dirty white motor cover, then the went to black and this unit was used until 

GM no longer offered power antenna in their vehicles.   The finally got it right and the Slimline is very reliable if you discount the plastic cord that breaks. 

 

Over the years I have gone from the factory replacement cords for the Slimline to weed whacker line to plastic coated steel....depending on the antenna design.

I recently discovered that weed whacker line is made in 3mm size but hard to find except from outside the US.   All the GM antenas used plastic cord that was around .120 in diameter. 

3mm = .118 so it is ideal but hard to find, comes in short sections and is expensive.  

I have lots of stories but this should give you an idea of all the different power antenna used on GM cars.

PS If you find a replacement for your late model GM car.... it will probably be a new unit made in Japan or China. 

Another word of caution.... we believe a Corvette vendor had reproduction antenna made (probably in China) they look exactly like the Slimline until you get down to the details. 

I have also seen these reproductions made for '70's GM intermediates (like the Buick GN)  I may need to do another post on what differences to look for. 

 

Edited December 8, 2022 by Barney Eaton (see edit history)