ConcoursMustang Forums

1st Generation 1964 1/2 - 1973 - Questions & general discussions that apply to a specific year => 1966 Mustang => Topic started by: Turnall on November 07, 2022, 11:20:31 PM

Title: 66 Metuchen GT Firewall - Oct 65 build
Post by: Turnall on November 07, 2022, 11:20:31 PM
What goes in the hole that I have plugged in the firewall?

I'm thinking window washer pump but are there different sizes?  I can provide more details if needed.


Allen
Title: Re: 66 Metuchen GT Firewall
Post by: jwc66k on November 08, 2022, 01:02:53 AM
The "third" hole is usually for fog lamp power. Your title says GT, where do your fog lamps get their power?
Jim
Title: Re: 66 Metuchen GT Firewall
Post by: J_Speegle on November 08, 2022, 01:15:04 AM
For a GT you need one hole (rectangle one) for the main engine compartment/headlight harness, one for the windshield washer wire loom and one for the GT grill/fog lights. How they are arranged/located on the firewall differs between assembly plants and possible production period

Sorry due to the lack of NJ cars from 65-66 I don't have a nice close up of an original unrestored car available to post. Fair share from the other plants but as mentioned they differ


May I suggest you add when and where (as well as other details you choose) to your signature do you don't have to include it or answer those questions each time you start a thread with a question ;)

Title: Re: 66 Metuchen GT Firewall
Post by: CharlesTurner on November 08, 2022, 01:55:53 AM
The big hole with the plug in it would typically be for the washer pump wiring.
Title: Re: 66 Metuchen GT Firewall
Post by: Turnall on November 08, 2022, 09:34:35 AM
The "third" hole is usually for fog lamp power. Your title says GT, where do your fog lamps get their power?
Jim

The gray wire powers the fog lamps.

It's hard to tell in the attached picture but the grommet on the aftermarket cable for the washer pump is too small to fill the hole in the firewall. I do not have the original cable. So I was wondering if there were maybe different sizes or if the aftermarket is just wrong.

Allen
Title: Re: 66 Metuchen GT Firewall
Post by: CharlesTurner on November 08, 2022, 11:37:47 AM
The original washer pump lead that I've seen with the big grommet has a black fiber sheathing on the wire that doesn't do well with age. 
Title: Re: 66 Metuchen GT Firewall
Post by: Turnall on November 08, 2022, 11:54:21 AM
That must be what this wire is. Can't find the other end of it in my warehouse.

Thanks,

Allen
Title: Re: 66 Metuchen GT Firewall
Post by: jwc66k on November 08, 2022, 02:54:24 PM
Here's a picture of a Oct 65 San Jose GT Fastback showing the three wiring groups coming thru the LH Firewall. From top to bottom: windshield washer power (an option); main under hood lights/starter/voltage reg plus harness; fog lamps (an option - front brake line "T" behind wire).
Note that they are mounted in a relatively straight up and down line.
Jim
Title: Re: 66 Metuchen GT Firewall
Post by: CharlesTurner on November 08, 2022, 03:44:33 PM
That must be what this wire is. Can't find the other end of it in my warehouse.



Yep, that's it, which is also the style used with the early washer pumper with a single connector as seen in your pic.
Title: Re: 66 Metuchen GT Firewall
Post by: J_Speegle on November 08, 2022, 04:54:36 PM
Here's a picture of a Oct 65 San Jose GT Fastback showing the three wiring groups coming thru the LH Firewall. From top to bottom: windshield washer power (an option); main under hood lights/starter/voltage reg plus harness; fog lamps (an option - front brake line "T" behind wire).
Note that they are mounted in a relatively straight up and down line.
Jim

As mentioned the location of the holes will be different on 66 San Jose from NJ built cars so if you don't have a 66 San Jose built car, IMHO based on pictures I have from all three factories, suggest you don't use the picture as a guide for the hole location  ::)  Notice how the 66 NJ holes are arranged in his picture
Title: Re: 66 Metuchen GT Firewall
Post by: sgl66 on November 08, 2022, 06:34:41 PM
As mentioned the location of the holes will be different on 66 San Jose from NJ built cars so if you don't have a 66 San Jose built car, IMHO based on pictures I have from all three factories, suggest you don't use the picture as a guide for the hole location  ::)  Notice how the 66 NJ holes are arranged in his picture
Mine is the same as Allen's but then just because Metuchen never did anything consistent, there is this built in between https://www.concoursmustang.com/forum/index.php?topic=25760.0
Title: Re: 66 Metuchen GT Firewall
Post by: J_Speegle on November 08, 2022, 08:34:02 PM
Mine is the same as Allen's but then just because Metuchen never did anything consistent, there is this built in between https://www.concoursmustang.com/forum/index.php?topic=25760.0

Yes it appears to be multiple locations for the smaller hole. I mentioned earlier that there might be a difference for NJ for different locations based on production period. Thanks for reminding us of this example where the hole is below but to the center of the car on the car in the link with the door tag  showing Oct 16 and buck tag  Oct 25

Hopefully Turnall will share the car in question's projected and bucked date so we can compare and maybe determine at least a trend for this detail
Title: Re: 66 Metuchen GT Firewall
Post by: Turnall on November 08, 2022, 10:13:34 PM
Did you see my previous post with the information?

Alen
Title: Re: 66 Metuchen GT Firewall
Post by: J_Speegle on November 08, 2022, 10:38:13 PM
Did you see my previous post with the information?

Alen

Apparently yes I did Alen :( miss reply #4 added the projected date to the main title. Thanks since this helps us understand the time difference between the two versions we have seen so far
Title: Re: 66 Metuchen GT Firewall - Oct 65 build
Post by: jwc66k on November 09, 2022, 12:45:35 AM
Allen,
Are there indications that the windshield washer bag was mounted on the left front fender apron near the top between the radiator support and LH shock/spring housing? Two holes were required. There should also be 3 holes for mounting the windshield washer pump (two speed) below the area where the bag is supposed to be mounted.
If those items are not there, I would suspect that the rubber plug was to installed on the firewall to fill the hole where the pump wiring would have gone but punched inadvertently.
One more thing. If that is a Ford rubber, it would have a Ford hardware part number (6 digit number, a dash and the letter "S") on the outer ring.
Jim
Title: Re: 66 Metuchen GT Firewall - Oct 65 build
Post by: Turnall on November 09, 2022, 09:27:46 AM
Allen,
Are there indications that the windshield washer bag was mounted on the left front fender apron near the top between the radiator support and LH shock/spring housing? Two holes were required. There should also be 3 holes for mounting the windshield washer pump (two speed) below the area where the bag is supposed to be mounted.
If those items are not there, I would suspect that the rubber plug was to installed on the firewall to fill the hole where the pump wiring would have gone but punched inadvertently.
One more thing. If that is a Ford rubber, it would have a Ford hardware part number (6 digit number, a dash and the letter "S") on the outer ring.
Jim

Yes, 2 holes are there for the washer bag. There are 3 holes for the washer pump (not sure that it's a two speed as only one wire goes to it).

I installed the rubber plug simply to fill the hole as the reproduction harness (one wire) with grommet did not fit the hole.

Allen
Title: Re: 66 Metuchen GT Firewall - Oct 65 build
Post by: jwc66k on November 09, 2022, 02:38:47 PM
Measure the diameter of the hole. Use calipers. Or, if the plug is a Ford plug, the part number should give the dimension.
Jim
Title: Re: 66 Metuchen GT Firewall - Oct 65 build
Post by: Turnall on November 10, 2022, 09:38:30 AM
Measure the diameter of the hole. Use calipers. Or, if the plug is a Ford plug, the part number should give the dimension.
Jim

I couldn't get calipers in there anyway to measure the hole. By a tape measure it appears to be dead on 3/4" which is also the diameter of the inside portion of the rubber plug I had in it.

Allen
Title: Re: 66 Metuchen GT Firewall - Oct 65 build
Post by: jwc66k on November 10, 2022, 05:16:19 PM
I "tried" to measure mine, and pushed the windshield washer electrical feed thru plug into the area under the dash. It's 3/4 inch. Mine is a two speed washer, two wires to the pump.
Now. What are you trying to do?
Jim
Title: Re: 66 Metuchen GT Firewall - Oct 65 build
Post by: Turnall on November 10, 2022, 05:30:04 PM
I "tried" to measure mine, and pushed the windshield washer electrical feed thru plug into the area under the dash. It's 3/4 inch. Mine is a two speed washer, two wires to the pump.
Now. What are you trying to do?
Jim

Find an original wire with grommet. I have lost the portion of the wire (it was in two pieces) that still had the grommet and therefore my wire is too short.

Jim, not sure if you saw it, but post 6 shows the single wire portion that I still have.

Allen
Title: Re: 66 Metuchen GT Firewall - Oct 65 build
Post by: jwc66k on November 10, 2022, 07:58:40 PM
Getting closer. It appears you have a single speed windshield wiper, and your question is are the grommets used to go thru the fire wall a different diameter between the single speed and two speed systems. The only info I can supply is the hole and grommet is 3/4 inch for the two speed system. I would assume (it is Ford, so let the buyer beware) that the hole size would be the same - one less tool on the assembly line. So, your reproduction grommet may be incorrect.
(Whew.)
Do you remember where you got the aftermarket item from?
Jim
Title: Re: 66 Metuchen GT Firewall - Oct 65 build
Post by: Turnall on November 10, 2022, 09:16:42 PM
Getting closer. It appears you have a single speed windshield wiper, and your question is are the grommets used to go thru the fire wall a different diameter between the single speed and two speed systems. The only info I can supply is the hole and grommet is 3/4 inch for the two speed system. I would assume (it is Ford, so let the buyer beware) that the hole size would be the same - one less tool on the assembly line. So, your reproduction grommet may be incorrect.
(Whew.)
Do you remember where you got the aftermarket item from?
Jim

One of two places. NPD or a local parts house that has many old Mustangs and is a Scott Drake dealer. The local yard did have a 66 GT convertible but the washer pump harness was not there.

I feel certain the aftermarket part is incorrect. Finding a correct one may be a totally different challenge. I'll post in the want ads and see what happens.

Allen
Title: Re: 66 Metuchen GT Firewall - Oct 65 build
Post by: Turnall on November 10, 2022, 10:06:31 PM
Getting closer. It appears you have a single speed windshield wiper, and your question is are the grommets used to go thru the fire wall a different diameter between the single speed and two speed systems. The only info I can supply is the hole and grommet is 3/4 inch for the two speed system. I would assume (it is Ford, so let the buyer beware) that the hole size would be the same - one less tool on the assembly line. So, your reproduction grommet may be incorrect.
(Whew.)
Do you remember where you got the aftermarket item from?
Jim

My question is not and has never been are the grommets used to go through the firewall a different diameter between the single speed and two speed systems. I know my car is a single speed and what the diameter is. I very simply have questioned if the aftermarket single wire reproductions are not the correct size.

Sorry if you found my question elementary, but I'm simply trying to find the correct harness. If you find it a chore, please accept my apologies...

I do believe @CharlesTurner answered my question earlier in this thread by not only telling me what the one wire looked like, but also confirming the piece I have as being correct.

Allen