Cruise control

For all those wiring gremlins we love, this is the place to discuss them.

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Airjeter
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Posts: 7
Joined: Sat Mar 31, 2018 12:42
Model: Excel sa
Colour: Green
Year: 1989
Location: Stewarton

Cruise control

Post by Airjeter »

Car was in for some paintwork and for some reason they disconnected the battery..Now the cruise control is not engaging. Is there something needs reset? Appreciate any help.

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Hawaiis0
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Model: Excel SA (No 3); Elite 504
Colour: BRG; Dirty White
Year: 1986
Location: West Oxfordshire

Re: Cruise control

Post by Hawaiis0 »

Where were they painting? Battery should not make any difference.

Mine is on a quick disconnect and it's on and off loads. It is mainly earths; brake switch (how are your brake lights?) and the speedo pick off.
Nothing is fool proof. Fools are clever!

Airjeter
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Posts: 7
Joined: Sat Mar 31, 2018 12:42
Model: Excel sa
Colour: Green
Year: 1989
Location: Stewarton

Re: Cruise control

Post by Airjeter »

They were painting bonnet, no reason to disconnect battery. Brake lights working, will have to check speedo switch. Seems strange as was working perfectly before coach work visit.

fairline38
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Posts: 42
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Model: Excel SA
Colour: Black
Year: 1987
Location: London Finchley
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Re: Cruise control

Post by fairline38 »

My 1987/88 SA developed a serious clicking noise near the intake manifold, which sounded like there was a serious issue near the top of the engine. The ticking sound only occurred when the transmission was in DRIVE. The noise ceased when either the brakes were applied or the car built up speed, but would return when slowing down.

I assumed it was the brake servo non-return valve. Steve at SJ agreed and he supplied me with a replacement brake servo non-return valve. It was a ten minute install.

Unfortunately this was not the problem. With the help of my son-in-law standing at the passenger side of the engine bay he could clearly hear, see and feel the knocking noise inside the cruise control actuator. We first removed the fuse (no 4 - which also controls the stop lights) and the noise subsided. I then removed the back panel of the glove box and disconnected the actuator plug coming through the firewall to the CC ECU behind the glovebox, completely removing (I believe) all electrical power to the actuator.

I just completed a test run down the M1 and all seemed well until one moment when the noise returned for a short period...once again to dissipate when I applied the brakes!

Any ideas what may be happening? Does anybody know:

1) Who is the manufacturer of the cruise control actuator?

2) Does the actuator have both electrical and mechanical mechanisms?

3) Can the actuator be rebuilt?

4) Has anybody had similar issues.

Most of you know that the SA is a very rare breed. I understand that less than 40 were ultimately produced.

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Hawaiis0
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Posts: 3785
Joined: Sun Jun 30, 2013 18:39
Model: Excel SA (No 3); Elite 504
Colour: BRG; Dirty White
Year: 1986
Location: West Oxfordshire

Re: Cruise control

Post by Hawaiis0 »

fairline38 wrote:
Sun Mar 21, 2021 13:13
Does anybody know:

1) Who is the manufacturer of the cruise control actuator?

2) Does the actuator have both electrical and mechanical mechanisms?

3) Can the actuator be rebuilt?

4) Has anybody had similar issues.

Most of you know that the SA is a very rare breed. I understand that less than 40 were ultimately produced.
The actuator and control module are VDO used on BMW of the era.

Disconnect the module behind glove box rhs approx
Nothing is fool proof. Fools are clever!

lambert.john
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Posts: 272
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Model: SA
Colour: Blue
Year: 1987
Location: Luton, Bedfordshire

Re: Cruise control

Post by lambert.john »

I do find the cruise control useful on long motorway journeys (so long as traffic is not too heavy). However, I do find it a bit jerky i.e. I can feel, through the seat and steering wheel, the power constantly cycling on and off in order to maintain the required speed. I am sure I haven't noticed this in other cars I have used with cruise control. Do other SA users find this? Could it be a faulty actuator?
John L.

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Hawaiis0
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Posts: 3785
Joined: Sun Jun 30, 2013 18:39
Model: Excel SA (No 3); Elite 504
Colour: BRG; Dirty White
Year: 1986
Location: West Oxfordshire

Re: Cruise control

Post by Hawaiis0 »

The actuator will be constantly pulsing as it pulls the throttle and then relaxing as it hits speed setting. As the car slows as soon as the 'throttle' is relaxed the system will request another throttle pull to get back up to speed - just like your right foot does on the pedal. I assume it to be normal for a cable driven system.
Nothing is fool proof. Fools are clever!

Marten
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Re: Cruise control

Post by Marten »

lambert.john wrote:
Sun May 22, 2022 23:24
I do find the cruise control useful on long motorway journeys (so long as traffic is not too heavy). However, I do find it a bit jerky i.e. I can feel, through the seat and steering wheel, the power constantly cycling on and off in order to maintain the required speed. I am sure I haven't noticed this in other cars I have used with cruise control. Do other SA users find this? Could it be a faulty actuator?
I'd look into the system and try to find if there is any adjustment possible for the sensitivity, ie when it starts to correct for deviation of the set speed, and how much throttle it gives to get back on track

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