70Post

Adding a power window setup to a '70 442 convertible. DO NOT know what GM brand the donor setup came from.

Most everything makes sense and almost everything is connected now...BUT.....the setup included what I've been calling the "mystery wire"....it's called a "Master Power Splitter" (herein "MPS") over on George N's Buick website in his power window conversion tutorial. BUT (there's that "but" word again).....the MPS I have has a ring terminal end on the single orange/2 black stripe wire end. The ring terminal end is the same style/size as the power convertible top orange/2 red stripe wire that gets connected to the circuit breaker on the firewall (engine compartment side).

Again, I don't know the "source" for the used harness/setup we're installing here.

Looking in the '70 PIM (Assembly Manual) - Section 12, Page 162 - it seems to be indicated in the upper L hand corner of that page that a wire for the POWER WINDOW SETUP and a wire for the CONVERT TOP setup would be connected to the D side post of the firewall-mounted circuit breaker.

BUT - looking at the wiring diagram in the '70 Chassis Service Manual it (Abody diagram at 12-2 "Chassis Electrical" chapter) it makes it look like the power window feed plugs directly INTO the fuse box (on the "ACC" spade terminal).

I'm probably overlooking something obvious here or reading things wrong....who knows??

>DOES ANYONE HAVE A KNOW ORIGINALLY EQUIPPED '70 442 Convert w/power windows??? Not interested in looking at pics of "converted" cars.

>I looked at Scott Wynn's thread but the pics showing the fuse box and circuit breaker are too dark and the wires are too dirty/greasy to tell what is routed where, etc. Great thread for some routing info to the doors, etc but I can't see anything at all as it relates to the use of a MPSS, the firewall-mounted circuit breaker and any fuse box connections.

SEE MY PICS(with text) below for more info. I can take more pics as well.

Thanks very much.

70Post

Here's a pic from George N's Buick site of the style of MPS he has. Apparently on the Buick application the L end of the wire gets attached to the "ACC" terminal on the fuse box. The MPS I have has a factory/original looking RING TERMINAL end on it instead of the red plastic housing on George's wire below (which has a female spade terminal inside to slip over the male spade terminal on the fuse box).

Fun71

I got nothing helpful. I work in a world of TLAs and couldn’t help but notice that it should be MPS instead of MSP.
Like I said, nothing helpful.

matt69olds

I think the power top, power windows, power door locks, etc, are powered from the circuit breaker to the power splitter. The power window RELAY is powered up by a pink wire that plugs into a ignition circuit on the fuse box.

The way I think it’s designed to work is as follows: the ignition circuit powers up the window relay (this prevents the windows from operating unless the key is in accessory or run) the motors are powered thru the relay off the circuit breaker under the hood.

I don’t have a 70 service manual, but if I remember correctly the 69 body manual I have works as I described.

Koda

closest I got is a grungy 67, but im fairly certain it's original.

70Post

Thanks Kenneth - typing too fast and too late last night. I corrected it.

70Post

Thanks Matt and Koda - The orange (or light red)/2 black stripe wire hanging in front of the fuse box and the pink wire I have plugged into the "IGN" spade run to the power window relay behind the D side kick panel....there's a third wire in the relay as well - a dark red wire/white stripe and that wire runs over to the 4 toggle driver's door panel gang switch to provide power to the 4 switches.

The '70 wiring diagram makes it appear that the "ACC" spade terminal IS fuse protected and that it may be the 20A fuse to the right of the spade terminal. (NOTE: I call it the "ACC" spade terminal but in reality the fuse to the R of this terminal is labeled as "ACCSY PWR RELAY" so I just "borrowed" the "ACC" to title that spade terminal).

Here are pics of the '70 Chassis Manual Abody wiring diagram (the fuse box itself) AND also Section 12, Page 162 from the '70 PIM. They seem to conflict.....maybe I'm just not "reading" them correctly.

4speed455

My car is not original but I have the same harness you have and the same MPS. I’m not sure of what car it was removed from originally. I do have everything connected and working properly. Mine is a 70 convertible with power windows and power seat. I have the pink wire going to the top ACC spade terminal with the note that says “.....& Power Window Relay” I have nothing connected to the IGN terminal. On my harness the orange with two black wire coming out of the window harness is the feed for the power seat which I have plugged into MPS which is connected to the firewall circuit breaker terminal. I believe the note “Fastened by Fisher for Power Door Locks, Power Windows or Power seat” is referring to the MPS and the other options the can also be plugged into it. The power top has its own lead connected directly to the circuit breaker.

70Post

Joel - Thanks for that. Looks like I'll use this MPS and run the pink wire to the "IGN" spade terminal on the fuse box. I'll run the ring terminal end of the MPS through the firewall accessory grommet and hook it up to the circuit breaker post.

Can you tell if your MPS has the rubber grommet slipped on over the orange/2 black stripe wire? That indicates it passing through a hole in sheet metal but the PIM shows the MPS wire just running through a hole in the already-installed rubber accessory grommet. Maybe that rubber grommet on my wire isn't utilized.

Thanks

4speed455

As I said I have my pink wire on the ACC terminal and it works correctly, I only have power to the windows with the keys in and turned to acc or run. My MPS does have the grommet exactly like yours shows and it is running through the already installed accessory grommet, but like I said mine is also a conversion. I think if it wasn’t a convertible it wouldn’t have the accessory grommet, so it would use the smaller one on the MPS wire. Maybe on a factory setup for a convertible the MPS wire wouldn’t even have that smaller grommet , and would only use the larger accessory grommet.

70Post

Makes sense on the integral grommet.....thanks again everyone for the help on this.

Koda

I would not put it past GM to have used the same power wire that would be underrated for all accessories going at once, figuring that one person can only hit so many switches at once. In other words, don't put the windows and ragtop down at the same time.