What are some common failure points of the cruise control system? I have a long road trip in my future and if possible would like to have a working cruise control unit. I will be troubleshooting it tomorrow and fixing whatever I can.

Has anyone use the 944online cruise control brains that are refurbs? They have a 2 year warrernty and after core charge they are only $99. Sounds like a deal to me I don't know.

 

On the 928 problems can be from vacuum (sometimes) though that is apparent with how hvac system works, or does not work. Usually it is the brain that has gone bad. By gone bad I mean the solder joints have become loose and need resoldering. Third problem (but unusual in my experience) is the control unit.

I have been told that de to age some of the joints will crack and not make contact. I have resoldered 3 for my 928's and 2 worked again. The one that did not smelled of burnt electronics (but I tried anyway)
One sign of resolder being needed is if when set the car continues to speed up.

I am not sure of the 944 system. My '90 cabriolet works perfect. The '87 will speed up, and the '84 will do nothing at all.

I know that the system will shut off with brake pedal or clutch. Perhaps one of those is not making correct contact. As for the refurb brains from Ian that seems to be a good price if it is the brain that is bad. I guess an easy way to check is borrow a friends whose is working or put yours in his.

 

I think the Cruise computer is normally the issue.

Changed my cruise brain with a used one I got off someone here for $35 and it works perfectly now. Was doing nothing before. An easy fix especially if you enjoy yoga. Its up under the dash near the drivers side wheel well.

 

The Cruise brain and the servo are the two top items of failure. The brain solder joints are prone to failure. The servo contacts are often in need of cleaning.

 

I'm not sure if the cruise works or not yet. I hope it does but who knows.

 

I know that when a brake light bulb burns out on my 968's the cruise will not engage. Also if you use LED bulbs!! BTDT

 

My cruise worked once in a while, then got a used one from ebay worked more consistently but was making a clicking sound at the servo so that one is coming off . Got one from rennlist member have not tried it yet will this week .
I would got with the one for $99.99 if it has two year warranty then you more then likely will not have any issues . And it is a tight job getting under there to replace it . Let use know how you make out.

 

Kingston, so if servo clicks it means it is usually o.k.? and problem is brain? I ask because my '84 will click on occasion.

 

Where is the servo located? I have an intermittent clicking, usually during warm months, coming from my passenger foot area, or behind the radio. I've been told it is possibly the cruise control but haven't pin pointed the source of the noise yet.

I've used the CC fine in the past. The clicking happens when the CC isn't set / engaged. I can't recall if there is an on/off on the CC, so I suppose the clicking could just be the servo adjusting as I am driving.

 

My cruise worked a little bit. Basically it would only accelerate but only while you had the stalk pushed forward. Then sometimes I could get to set the speed. Once I braked and tried to get it set again it wouldn't work. So I don't about it.

 

What would cause this type of problem?

 

THE cause is solder joints in the brain.
The servo is ok on mine I did clean the contacts and wiper under the cover. It is the brain and I just got one from rennlist member but have not had time to try it yet but will as I am know finished interlock paving the patio .Wife to do list, I could of been in the garage with the misteress (944) .LOL

 

Donde esta el servo? I'd like to figure out if that is the mystery clicking I am hearing when the cruise control isn't engaged.

thx.

 

Mine clicked when it wasn't engaged and only seemed to click for the first little while then seemed to stop not sure ?? This week will get the new time used part on.