1999 Oldsmobile Intrigue GL from North America - Comments

The only problem I have had with this car, and it showed up at around 92000km, was my HVAC head unit started to fail. No AC/Heat/Defrost, nothing!

There was power going to the unit, but the screen would go blank, or if the screen was on it would freeze on the last used setting, or it would work fine. It had a mind of its own. After taking it to a GM Dealer to get it diagnosed, they told me I had to replace the head unit for about C$600, labour included. I said no. Knowing how easy it is to do it myself, I went to a junk yard, bought one for $100 and installed it myself... same problem even after clearing out the codes. Hmmmm. Then I came here to read some complaints and noticed many others with the same problem. After returning the used head unit, I brought it to my cousin who works as a mechanic for a GM Dealership. After 3 days, he and his trim guy couldn't figure it out! It was again working intermitently and they couldn't get a code. Finally they got one. P1605 - Serial Comm. Error from the HVAC H/U to the PCM. He didn't have anymore free time to look at it and I said no problem, that info helps. I then finally enlisted a good friend of my fathers, a recently retired 30 year GM mechanic. In 30min he figured out what every other serviceman has been stumped about!

He traced the ground wire from the HVAC head unit to a connection under the right side of my dash. The screw holding in the wire wasn't completely tight, yet it was striped from the factory. He replaced the screw, and voila! I think the dude that was on the Intrigue line at the plant was either new or high as he seems to have affected many Intrigues with the same problem. No need to replace the HVAC head units folks!

The reason why I was having it working intermittently was that the ground wire is a high resistance line. When it would heat up outside, the wire would expand and make the connection. When it was cooler, it would not have enough contact to complete the connection. Genius!

BTW, I did have my headlights flicker, I think, once or twice before, no more after this fix. Why? The HVAC head unit controls the twilight sensor for the headlights because when my unit would freeze, my auto night time (twilight) lights would turn off and I had to manually turn them on.

I hope this has helped someone out there as I wish I knew before I spent $100 for a GM tech/kid to incorrectly diagnose the problem. I could have also spent upwards of a $1000 if it wasn't for Gus! Thanks Gus!

I love this car!

The engine is excellent, it runs so smooth. I have used Mobil 1 oil since 20000km. Maybe that helps.

Aside from the problem above, this car has been the most rock solid machinery I have ever owned. But I do take great car in my cars. I think I should be able to take this one to at least 300,000km with no major issues. At 94000km, it feels like I just broke it in. The gas mileage for this 3.5L 24 valve baby Northstar engine is excellent. On a C$35 tank, I average about 500km in the city and have reached 700km on the highway.

The leather on the front seats hasn't even cracked yet, but I do condition them every 6 months. The bank seat leather is of lower quality, but not much traffic there so it still looks new.

Aside from the plastic fantastic of the dash, I think its one of the finest cars Olds/GM has built for under C$35K. I highly recommend buying this car NEW or from someone that is really anal about taking car of their cars.

This ground connection, where exactally is it? and what does it look like? is it on the firewall of just on a random metal chunk. Thanks.

I have the SAME EXACT problem with my 1999 Olds Intrigue GLS. I bought the GM service manuals off of Ebay for about 60.00 USD each and I am going to try to locate this "ground wire". I have been searching high and low for about a year for someone who has already solved this problem, tried to avoid myself paying thousands trying to find out what was wrong. If I find this mysterious ground wire, I will re-post where it is.