Hi Everyone, I am excited to get the 1985 Mondial Cabriolet QV out soon here in Wisconsin once the weather turns a bit nicer. Here are a couple things I need some insight on: The car towards the end of last driving season developed a hanging idle. When shifting gears, between shifts the idle stays high, usually above 2,000 RPM (if I remember correctly it stays close to the RPM it was shifted from, but it's been a few months). It did not do this prior, otherwise idles smooth, still feels like it has proper power, etc. When starting it, it'll settle into a proper idle around 1,000 RPM and hold that. When the idle is high when changing between gears (2,000 RPM or higher), a tap or some modulation of the accelerator pedal can get the RPM to return back down. I have not done anything to try and resolve this yet. Is this sounding like some throttle cables that need to be lubed or an adjustment being needed to the fuel injection system, or...? The brake lights do not light up with pressing of the brake pedal. I have checked the brake pedal switch and that is working properly. I have checked the bulbs and wiring in the trunk and that is fine. I used a long wire to try jumping directly from the brake pedal switch at the front of the car all the way back to the wiring in the rear of the car in the trunk and this caused the the brake lights to work. I am hoping there is not a busted brake wire hidden somewhere between that is inaccessible. Is there some other component I am missing? Is there some sort of other relay, connector, or something? Any ideas other ideas on how to solve this other than stringing a new wire all the way from the back of the car to the front? Thanks in advance! Shane
What version 1985 Mondial Cab QV? US, euro, CH? For #1, certainly confirm the mechanical operation of the throttle plate mechanism first -- returning to the rest screw or not, floormat restricting acc pedal motion, etc.? For #2, the total current to run the (stock) brake lights is surprisingly large (like near 10A), and can "degrade" the connector(s) at the fuse-relay panel. One easy thing to try is just unplugging/replugging all of the white connectors at the fuse-relay panel -- not a long-term fix if doing that gets them working, but can be a clue for where the trouble is located.
1985 Cabriolet QV Euro Thanks for the reply. I remember looking at the schematic awhile back for the wiring and couldn't remember which spot was responsible for the brake light circuit.
Seems like a sticky throttle cable. The cable attaches to the throttle body lever, use some teflon type lubricant and shoot it down into the tube that the cable disappears into. Also put some lube on the throttle body lever itself, around the spring area. You might also remove the throttle pedal, lube the cable connector where it attaches to the pedal mechanism. The pedal itself actually levers on small bearings, it is a very well made mechanism, so clean and grease those. I doubt it is anything to do with the injection system itself. But there are internals in the fuel distributor that move up and down, the plunger. It is possible it is sticking. With the engine off, you could very gently push down on the fuel injection air intake plate, this levers the plunger in the distributor. Press slowly and release slowly, and you might sense if all is smoothly actuating.
Use my old friend Deoxit to clean up all electrical connections, including those on the fuse box connectors. https://caig.com/product/deoxit-d100l-2db/
I should've known that anything "Mondial" would be a problem . It's sort of a "some good news, but probably a lot of bad news" situation. The only thing that the fuse-relay panel does is supply +12V to the brake light switch on one of the large V (green) wires. Since you report that if you run a wire from the brake light switch's large R (red) wire terminal to the rear brake light bulbs it works = confirms you've got +12V on the large green wires = confirms all is OK at the fuse-relay panel. The bad news is that the way it works is when you step on the brake pedal, and close the brake light switch, the +12V signal on the large V (green) wire is connected to the large R (red) wire on the brake light switch which goes to an ECU (item 109f on the schematic called "Electronic unit for check control"). This ECU then is supposed to turn "on" the brake lights. Of course, there is no information given about what's inside ECU 109f. Is your "check control" stuff sort of working, or is it completely dead? If you don't have a copy of the euro MondialQV wiring diagram 251/82, give a shout, and I can post a link to a pdf copy.
Hi Steve, Thanks for the reply and insight. I found prior posts from you with links to the schematics so thanks for posting those. The "check control" stuff is working properly it seems. The warning light for the brake lights does come on when the brake pedal is pressed. The warning light for "servicing needed" is on right now too as I have not reset it yet. There is a spot on the fuse panel where the white plug was toasted and a prior person enlarged the hole for a spade connector to go through and plug directly to the male connector. I'd still be interested in knowing which of the fuse panel wires are related to the brake lights.
Fuse panel : the vertical white plug with the wires on the right side, second upper 2 wires V (green) are connected inside the fuse panel with the lower side of fuse 28 (the last one the right side). Those green wires are going both to the stop light switch nr. 28. 1 green wire connected to stop light switch splits - 1 going to the hazard light switch - 1 going to sun roof switch Inside stop switch when pedal pressed makes contact to a Red wire that goes to the 109f control unit. And from there to the stop bulbs. 1 green wire connected to stop light switch make contact when released to a Red/black wire that also goes to control unit 109f and from there also to the bulbs. How this exactly works is still a mistery for me....
