'00 Montana - TONS of electrical problems

[DarryDoo]

Greetings, all.

Bought a 2000 Montana out of necessity about 6 months ago. Against my better judgement. My wife liked the colour.

Looked around the site a bit, and I see many of my issues listed singly, but not many vehicles with multiple issues, and none with ALL these issues. Thought I'd list them and see if anyone can see a common cause to investigate, or if I just have a piece of... poo.

1. Passenger power window does not operate from either switch.
2. Passenger power door lock does not function.
3. Passenger power door lock switch will lock doors (except passenger side, see #2), but will not unlock doors.
4. All lights flicker. Digital voltmeter at cigar lighter shows steady voltage. Unknown if ground screw was replaced.
5. Fuel gauge works until about 3/4 tank, then shows full until tank is almost empty.
6. Rear quarter windows inoperative. They worked for many months, stopped for about a week, worked again for a month, and now failed for 3 months.
7. Only centre of radio display is visible.
8. Overhead console computer sometimes goes very bright for a second or 2, then returns. Occasionally has reset itself (which sucks since the fuel used is the only reliable method for knowing how much gas is in 'er!).
9. About 2 months ago, the odometer lost over 150,000 km. I was delighted -- and ready to sell! Went back to proper km's about 2 weeks later. Missed my window of opportunity.
10. Air pump inoperative. Haven't looked to see if it was disconnected due to suspension issues.

Most of these problems have developed in the past 6 months, except #5 and #10, which were there when we bought her.

If no one sees a common cause or 2, I guess I'll just tackle them as individual problems.

Thanks in advance!
Darren

Just have to add: "When in danger, or in doubt, !"

[1999montana]

Hello Darren,

Welcome to the forum... a place whree you can usually find a solution for just about any ailment these vans may develop.

Items 1,2 and 3 could be related to a corroded wiring bundle that runs under the step plate on either side of the van. The reason for this is condensation (literally tons of water) that fails to exit the van through the air con drain in the firewall and finds its way under the carpet and into the channel that the wires sit in.

Connectors are the first to go, followed by a short life span for wires exposed to the moisture. If your carpet on the driver's side has ever been wet when it shouldn't have been, this is a good root cause to examine further.

Our door locks began doing what you describe after a long trip of 11,000 kms out west and back. First indicator was less than 12 volts at certain points along the wiring to the locks. Air Con was on all the time. The drain for the AC runs out through the firewall and clogs.

Problem is, the drain is almost invisible from under the van, but is about 18 inches up from the floor pan on the passenger side. You have to feel around with you hand until you find a 3/4" hole in the insulation. If clogged, this fixes the root cause.

Now you must trace the wires through the doors to the floor pan channel area (described above) to see if there is corrosion in the wiring. A slow, painful process, but rewarding when windows and locks start working again!

I can tell you if you take it to a dealer they know the problem and can isolate it really quickly because they fix so many. (Not recommending this of course, only to point out that GM knows about the problem and fixes).

Item #4 could be the ground screw and you can get one from your GM dealer and install it to see if that fixes the problem (Don't know the part number, but your parts guy will know what you are talking about). It could also be the dimmer part of the headlight switch...(dirty or on its way out). I notice if I have the dash lights down really low, the DIC will flicker independent of the light level in the dash. Moving the dimmer a notch fixes this. The other possibility is a dirty ground reference at the battery or chassis, a dirty positive post, or worse, a battery that needs replacement.

Item #5 might be fixed with a liberal amount of fuel injector cleaner. I ran into this problem with a bad load of Shell gas in Victoria on our trip. Stopped at a CTC and picked up three of those multi application fuel injector bottles with the measurement/applicator on top (usually sells for $9.99 but buy it when on sale at $4.99). After leaving Victoria and heading east to Calgary, the gauge was working again by the time we reached Helena, MT.

Item #6 could be part of items 1,2 and 3, but I don't know for sure. There is a link on here from GregA that has wiring diagrams for the windows, (I think).

Item #7 is a common problem. Some say you can take the radio out, remove the face plate and unsolder and re-solder new bulbs in it,...I don't know.. thought it was an LCD display, perhaps not.

Item #8 - What you describe is the normal function when the two buttons are held down to reset the display...have no idea how it can do this on its own though...sounds like junkyard time to look for a spare one to see if it still does it.

Item #9 - no comment, ours is analog

Item #10 - if the shocks are original, then the pump may have run all the time due to a leak in one or both. The fuse may have been pulled; - its marked as ALC in the right side fuse panel on the passenger side inside the door on the side of the dash panel. Another possibility is that the small link arm that attaches to the leveler control seized and broke off causing the shocks to pump to max. This link is attached to the transverse cross link on the suspension.

If you get the pump working, check the hoses for leaks. If none, then (with the van properly supported on stands) move the lever on the leveler through its range of motion to see if it releases air and calls for the pump. If it does, then all you have to do is decide if the shocks are good or need replacement (go with the Monroe replacements (about $170 for the pair; - be prepared to struggle with the lower mounting bolt on each shock too)

Hope some of this helps..come back and post your results when ready, OK?

[DarryDoo]

Awesome! Thanks for the quick reply, and the breakdown! I'll let you know how I make out.

Cheers
Darren

[rkvons]

Originally Posted by 1999montana

Item #5 might be fixed with a liberal amount of fuel injector cleaner.

I am a huge fan of Chevron Techron fuel system cleaner. I just had to do it to my van again because it would be full until 1/4 tank and then drop like a bomb. This fuel system cleaner also makes it run better.

[1999montana]

Originally Posted by DarryDoo

Awesome! Thanks for the quick reply, and the breakdown! I'll let you know how I make out.

Cheers
Darren

Well?