I bought this 1999 Dakota 4x4 and was told it needed a new multi-switch. The dash and cluster was in the back seat when I bought it so I had to plug the cluster and headlight switch up to drive it home. Noticed that when I pressed the brakes the cluster lights would mess up and I had no tail lights. The next day I checked and changed fuses and everything seems to be working right except a few things. 1.The cluster lights still mess up when brakes are pressed. 2.The blower barely works and messes the cluster lights up like the brakes do. 3.The wipers have no delay, just off, low and high. The previous owner said he changed the heater core so I'm guessing he didn't hook something back up or pinched a wire or something. Sorry for the long post just wanted to cover everything I know so far. All help is appreciated.

 

Think I figured out the culprit.... I'm going with the ctm is bad. Checked every wire and connector and everything looks fine. Noticed that the passenger side floor is wet and the ctm is under that side of the dash and the heater core was just replaced so maybe the ctm got wet at some point. Now I just have to figure out the cheapest way to replace it. Is it just plug and play or does it need to be (re)programmed?

 

The ctm has nothing to do with the blower motor nor the tail lights. It actually sounds like you have a bad/missing ground.

There should be a heavy ground wire from the body to dash near where it rolls on the drivers side.

 

I didn't find any wires undone while I was taking the dash back out. I forgot to mention that when I was checking fuses I plugged one into the power door locks and it was like it was stuck trying to lock so I left that fuse out. The tail lights worked after changing fuses. Apparently the ctm controls everything that was messing up after I fixed the fuses. One other thing I noticed today was that when I turn on the fog lights the relay buzzes so I switched it with the horn relay and both are still good. The previous owner said he thinks it needs an ignition switch too cause sometimes it will shut off with the key and sometimes it won't and he would have to unplug the auto shutdown fuse under the hood. I'm going to put the dash back in next week sometime and see if anything changes. And the inside lights don't come on at all unless I push the ones by the windshield on. I was thinking it was a ground at first but I cannot find any that are loose or not connected anywhere. I have been over this truck more in the last day than I have my 97 in the past 3 years looking for bad wires. I don't really won't to take the hvac unit out and have to refill the coolant to check for bad wires in and behind it. I did find something odd, there was a wire under the drivers side dash that had a ground connected to the other grounds, a small connector that didn't look like it even belongs in the truck and a thin white and a thin red wire going through the firewall and just hanging by the brake booster. I'll keep checking for bad wires and try a new ctm but I guess if I can't figure it out I will just swap stuff with my 97 and use the 99 for a toy. I also have an 01 (or maybe 03) Durango right now. Would I be able to swap the ctm from the Durango to the Dakota to see if that is the problem without messing anything up?

 

No on the '03 to '99 ctm swap. Dodge changed the computer bus in '01 and they are not compatibile. It went from a two wire, CCD, bus before '00 to a one wire, PCI, bus in '01+.

The CTM doesn't control very much in earlier models. It does control the power door locks and the dome lighting but not the headlights, fog lights, tail lights, brake lights or any exterior lighting. It does do the intermittent wipers. It does not do the heater at all.

 

Could it be the cluster itself?

 

It really sounds more like a bad ground. You could temporarily try adding a ground to see if the problem goes away.

The tail lights AND the wipers share a ground. It's actually located up by the battery, just to the rear of it.

Try running a cluster self test. Key off, hold down the trip reset and turn the key on. Continue to hold the trip button down until the display reads CHEC. It'll sweep the gauges and test all the bulbs. Any codes will show up in the odometer. It'll say 999 when finished.

 

I did the cluster test and it had no problems. The only place I haven't looked at for bad wires is in the doors and back panels and under headliner and behind hvac unit. All they will have to wait for a sunny day when I'm not working tho.

 

I'm with Dan, sounds like a ground issue.

 

Is there any diagrams that shows where all the grounds should be?