Why are my Stag's electric windows slow?

Owners most often trace it to tight or wrong felt in the glass channels, or to voltage drop at the switches and connections. Feeding the motor directly from the battery with fused leads separates the two: if the glass then moves freely, the fault is in the switch or wiring.

Do the windows need to be down to fit the hardtop or move the hood?

Yes. The door glass runs against the hood's side rails and seals, so operating the roof with the windows up drags glass across the seals. Once a hardtop is on, raise the glass and check it seals cleanly against the top's frame.

Why does my window glass rattle with the hardtop on?

Look first at the glass channels and their felt, then at the hardtop's fixings and seals. Rimmer Bros list shims for aligning the channel brackets to the door frame, which shows the channels are meant to be set up rather than simply bolted in.

Ownership / Windows, Door Glass and Hardtop Seals

Windows, door glass and hardtop seals

The Stag's door glass is raised by an electric motor and regulator in each door and runs in felt lined channels. Most slow, noisy or rattling windows come down to the channels and their felt, voltage drop in the wiring, or a regulator that has come adrift. With the hardtop on, the glass has to meet the top's seals, so channel alignment matters as much as the seals themselves.

Door glass and quarterlights

Each door carries a frame with a quarterlight ahead of the drop glass. Rimmer Bros list Mk1 door frame assemblies with clear quarterlight glass and Mk2 assemblies with tinted glass, so used parts need matching to the car. Quarterlights that stick are a known owner topic; the archive has not yet published a verified procedure for freeing one.

The door glass runs against the hood's side rails. Always lower both windows fully before raising or lowering the hood, or fitting and removing the hardtop. The soft top and hard top page explains why.

Regulators and motors

Rimmer Bros list the lift motor and regulator as one assembly per door, with the motor also available on its own. Owners describe the regulator arms as working like scissor blades, so keep fingers clear of the mechanism whenever the motor might run with the door trim off, and disconnect the battery earth before working inside the door.

A window that drops suddenly and will not rise has often had the regulator's bush jump out of its channel, according to owners. Tape the glass up before you start, so it cannot fall when the regulator is disturbed.

Channels and felt

Rimmer Bros list front and rear glass channels, a lower channel, a seating strip for the glass lift channel, and flock or felt kits for each door, in original equipment and reproduction qualities. They also list shims to fit between the channel brackets and the door frame to align the channels. Owners report that felt which grips the glass too tightly is a common cause of slow windows, so a new kit needs checking for free movement before the door trim goes back.

Slow electric windows

Note whether one window is slow or both. Both together points to the supply.
Feed the motor directly from the battery with fused leads. If the glass moves freely, the motor and channels are fine and the fault is in the switch or wiring.
If it is still slow, look at the channels and felt, then the motor.
Measure voltage drop across the switches and connections, as the electrical guide describes, and clean or renew the part that shows it.

The fault finder entry for slow windows gives the same tests in its usual format.

Rattles and seals with the hardtop

The hardtop's fixings vary: some cars carry factory mountings, others period or later aftermarket kits. Check every clamp and bolt for your top's kit is present and the seals are seated. Do not overtighten the clamps, which distorts the roof and cracks the paint. Once the top is on, raise the door glass and check it seals cleanly against the top's frame.

If the glass does not meet the seal, look at channel alignment and the regulator before blaming the seal. The archive has found no reliable Stag specific sequence for diagnosing hardtop rattles; ask the club if one persists. See the fault finder entry for hardtop rattles.

Questions

Why are my Stag's electric windows slow?: Owners most often trace it to tight or wrong felt in the glass channels, or to voltage drop at the switches and connections. Feeding the motor directly from the battery with fused leads separates the two: if the glass then moves freely, the fault is in the switch or wiring.
Do the windows need to be down to fit the hardtop or move the hood?: Yes. The door glass runs against the hood's side rails and seals, so operating the roof with the windows up drags glass across the seals. Once a hardtop is on, raise the glass and check it seals cleanly against the top's frame.
Why does my window glass rattle with the hardtop on?: Look first at the glass channels and their felt, then at the hardtop's fixings and seals. Rimmer Bros list shims for aligning the channel brackets to the door frame, which shows the channels are meant to be set up rather than simply bolted in.
Are Mk1 and Mk2 door frames the same?: Rimmer Bros list Mk1 door frame assemblies with clear quarterlight glass and Mk2 assemblies with tinted glass, so check which your car has before buying used parts.

Sources: parts and Mk1 and Mk2 differences from the Rimmer Bros catalogue, Triumph Stag door drop glass controls and fittings; regulator safety, dropped glass and tight felt from owner advice reported on the Stag Owners Club forum; hardtop handling from the archive soft top and hard top page. The archive has no verified procedure for quarterlight repair or for removing the regulator, and refers readers to the workshop manual.