Cruise Control Problem Exposed!

[Guest jim_houston]

If you have been reading my emails asking for assistance on how to solve my cruise control problems, I found out what it was. Someone suggested that I verify all of my vacuum hoses and I did that. They seemed fine. Last night I was working around the motor, and I bumped one of the vacuum hoses that is joined with a plastic "T". What I found was the plastic "T" (and actually a LOT of other plastic parts around the motor) are disintegrating. It broke into peices with just a little pressure. The more I looked, the more I saw that happening on lots of plastic parts. The plastic covers that surround the wires - all of that is breaking up with just the slightest touch.<BR>Try pulling the plastic shroud that covers some of your small electrical wires away and you will see what I mean.<BR>Anyway, I temporarily fashioned a seal using duct tape (duck tape?) and I plan on taking the broken parts to a Buick dealer and getting replacements. Bottom line: My cruise control now works.<BR>This little "find" saved me at least $60 for the "diagnosis" fee my local Buick dealer charges.<BR>Hope this helps someone.<BR>Jim Houston<BR>-charleston, sc-

[Guest]

I wish the repair on my '88 was so cheap & easy! I did find a large hole in the vaccuum hose, but that was just the start of it.<P>If you are having cruise problems I suggest that you pick up 2ft of 5/32" hose (~$0.70/ft) at your local parts shop and a very sharp utility knife or razor. Rather than twisting and tugging on the fragile plastic parts, just take the knife and slice the ends longitudinally at the to release their hold. I learned the hard way by inadvertently snapping off the plastic nipple on my vacuum reservoir and had to scramble to pickup the only unit in the Mpls/StP area (~$12.00 w. tax).<P>I rerouted the hose so that it was not in such close proximity to the engine. The circuit was now sealed and the cars somewhat rough idle settled down quite a bit.<P>The cruise still did not kick in so I checked out the diags on the car and it pointed to the CC/turn signal switch which is no longer available from GM. I opened up the frony plate of the switch and measured the voltage on the three exposed solder joints. Looked good. Removed power from the ckt and checked resistance. What it should be, the resistance increased/decreased when the set, resume, & accel buttons were depressed. GM specifically states not to measure the resistance in svc manual as it could damage the ckt. Anywho, the switch gear was fine.<P>Moved on to the next simple part, the cancel switch on brake and that "appeared" to be fine. The last two components of the ckt (other than fuses) I did not know enough about to test, the wheel speed sensor and the servo, so it was off to the dealership.<P>To make a long story short, their $85 diagnosis pointed at the discontinued cc/turn signal sw. and they handed me a bill for $121. Yeah, right. I asked to talk to the mechanic that worked on the car and went through his diagnosis and told him about my tests.We went back to the car and after showing him that you needed to turn the Cruise switch on the dashboard on to activate the system (have I mentioned the $121, yet!), the diagnosis changed to the system being OK. Fine, then why didn't it work? I authorized replacing the brake switch ($40.75 incl. labor) and during a test drive the system attempted to activate, but kicked out. This pointed to the servo assembly ($275.00 + labor). After replacing that, the system was on-line and fine.<P>Ugly as it sounds, the final solution was to throw parts at the problem until it went away. The diags for this simple circuit are very unreliable and IMHO not worth the $$$.<P>The final cost was $471.22 (ouch!) and worth it to me if the system holds up for the remainding the life of the vehicle.<P>Buick dealerships will print out TSB 83-90-08 for diagnosing the system if anyone thinks they REALLY need it. Its moderately helpful at best. If I had it to do over again I would:<P>1) Check fuse<BR>2) Visually inspect vacuum lines, recommend to just replace em for less than 2 bucks.<BR>3) turn on car and check for vacuum on line going to servo prior to connecting. There should be hickey force suction ( sorry, I don't have a vacuum gauge!) at the end of the hose and a change in idle if you seal the end. Turn off car and connect hose to servo.<BR>4) Replace brake switch $12.32. (PN 25529860)<BR>5) Ugh!! Replace servo $275.00 (PN 25074625) I hafta assume there are NAPA/Pep Boy parts for less!<BR>6) Drive wheels off car!<P>Hope this helps!

[Guest]

In the add insult to injury dept. I saw the dealer cost vs. retail screen on the parts dept. computer and there is a 100% markup!