grey Posted February 5, 2014 Report Share Posted February 5, 2014 There are three problems with my instrument cluster: Long ago the odometer starting going crazy-town and it runs backwards now. Fine. Whatever. This story begins when the dash illumination lights went out. First one bulb, then the other. I've been using a clip on light, and I finally got to looking at it over the weekend. I partially pulled the panel to do a basic visual inspection since they're on top. The soft circuit *looks* fine (though there is certainly wear to where they twist), and for magic-voodoo-reasons the lights have come on and cut off independently and randomly but they don't stay on. The bulbs *look* fine too. Sort of stuck on that one. So I put the panel back in, and finish up for the day So the next day my wife, who is the regular driver, tells me the speedometer stopped working. The tachometer works fine, but the speedometer sit's limply at the bottom. So tonight I fought the wheel bravely, and managed to pull it off and got the whole cluster out. The cables are all on securely, and I can see the end of the speedo cable waiting earnestly in it's socket. Then when I plugged it back in the, "dim" headlight light was out. Rats! So apparently it's some sort of quantum problem where by inspecting the problem caused more problems. Anyone have experience debugging their instrument cluster? Dash lights and speedometer are 'safety' things so I'd like them to work again. I'd appreciate some recommendations on how I might proceed. Quote Link to comment Share on other sites More sharing options...
tulaweb Posted February 5, 2014 Report Share Posted February 5, 2014 The speedometer is usually the cable but if the odometer is running backwards I have to guess, well no I have no guess for that. With the combination of things you describe I'd start with assuming a bad ground. most of the idiot lights are interchangeable with the two cluster illumination lights on top of the cluster, so if you have one known good one, switch them around to see which could be just the bulb. Use some contact cleaner to clean the two connectors and their mating surfaces on the circuit board. There are two ground blocks near the back of the headlights in the engine compartment. Those are the root of all evil with electrical problems. Remove, clean and replace all the connectors on that. Quote Link to comment Share on other sites More sharing options...
andrethx Posted February 5, 2014 Report Share Posted February 5, 2014 welcome, grey! when you have a chance, please post your location, model year & configuration of your car, etc. we geek out on that stuff here. it certainly sounds like you have problems with your grounds, as dave suggests. as far as i know, a backwards-running odometer means that the speedo unit (actually, the odometer gears inside) is bad and needs to be repaired or replaced. given that you're having problems with the instrument lights, it might be easier to swap out the whole instrument cluster for a good used one as a first step or you could end up troubleshooting the lighting problem twice. also, you should check to make sure that your car is not looking newer as the odometer runs down.... andré Quote Link to comment Share on other sites More sharing options...
Bean Posted February 5, 2014 Report Share Posted February 5, 2014 Hi Grey - I'd agree with Dave and Andre on their suggestions. The electrical functioning intermittently is almost certainly electrical connection, but I would guess it's at the plug for the cluster itself that needs to be looked at, or the ground. Regardless of these specific issues, I would look at cleaning ALL grounding points you can see. Pretty sure there is a grounding tree under the dash on the steering column, but for good preventative maintenance I would start pulling whatever connections you can and inspect, clean, and reassemble with some dielectric grease or something similar. Speedo cable is likely broken at the transmission end. I have heard that the generic speedo cable repair kit can fix these cables - but they tend to go due to lack of lubrication / maintenance. They show signs when the cable starts to get a bit jumpy and jerky, and when it starts bouncing is when the cable is starting to break. If you want to have a functioning odo then finding a used instrument cluster will be the way to go. If you can't find one locally I am sure one of our well known vendors of used parts could hook you up. Rabin Quote Link to comment Share on other sites More sharing options...
grey Posted February 6, 2014 Author Report Share Posted February 6, 2014 Thanks for the quick responses. I'll post some introductory stuff when I have a few moments. So I'm least concerned about the odometer. And "backwards" was not quite right. It actually runs in reverse dial order. Super strange. If there's some sort of chronological phenomenon associated with that, I certainly don't wish to take part! I'll try swapping some bulbs, and when it warms up a bit I'll tackle cleaning the ground trees. They're definitely calcified and oily, so I'm sure it wouldn't hurt to give them a going over. Any tips on getting them out and what to clean them with? Inspecting the speedo cable will have to wait... I'm having some nasty starter issues. I guess that will be my next post. Quote Link to comment Share on other sites More sharing options...
Bean Posted February 6, 2014 Report Share Posted February 6, 2014 Grounding trees are usually held on with a 10mm bolt. Wires just pull off, but I would take the time to gently snug up the female connectors so they bite into the spades when you reinstall. One thing I forgot to mention is that if you take the cover off the bottom of the steering column you will see the column is mounted with two nuts. Loosening those is an easy way to drop the steering wheel a little lower to get the cluster out. I often find its easier to do that than remove the steering wheel. Rabin Quote Link to comment Share on other sites More sharing options...
tulaweb Posted February 6, 2014 Report Share Posted February 6, 2014 I often find its easier to do that than remove the steering wheel. I find removing the wheel is really easy. A deep socket on a breaker bar easily removes the nut and two or three whacks around the back of the wheel and it easily comes right off. Quote Link to comment Share on other sites More sharing options...
Bean Posted February 6, 2014 Report Share Posted February 6, 2014 You are right when it is that easy - I've had more than a few that were ridiculously hard to come off. Like the only thing that worked was an air hammer on the shaft, and all the strength in my knees behind the wheel forcing it off at the same time... In those cases - couple Philips screws and 30 seconds of spinning 13mm nuts is much easier, so now I don't even bother with the wheel unless I have too. Pretty sure all my cars are/will be Momo'd though - so I'm not even sure I have to tough the wheel to remove the cluster. (ALWAYS leave the nut screwed on 5-6 turns when you're pooping the wheel off.) Plus - I invariably forget to mark the wheel and it goes on crooked a few times before I get it right. Rabin Quote Link to comment Share on other sites More sharing options...
grey Posted February 7, 2014 Author Report Share Posted February 7, 2014 I did the breaker bar with a deep socket approach. Getting it off the first time was a real hassle! Any recommendations on what to clean the groundtrees with once I get them off? Quote Link to comment Share on other sites More sharing options...
Bean Posted February 7, 2014 Report Share Posted February 7, 2014 Brass brushes, brake clean, and then I use Corrosion 3000 as my dielectric spray / protectant. Brake clean is pretty harsh - so use it well ventilated area and always wear latex/nitrile gloves. Rabin Quote Link to comment Share on other sites More sharing options...
ptootsov Posted February 7, 2014 Report Share Posted February 7, 2014 I can say that cleaning the grounding trees, especially the ones under the dash does make a difference. When I got my mom's car back on the road most the dash and button lights were dim or off. The digital clock would fade or go out completely. I spent time on a Saturday and cleaned all 6 trees and now all the lights are functional. Even the clock is on and keeps fairly good time. Peeter '87 505 STX Quote Link to comment Share on other sites More sharing options...
nolvad Posted February 16, 2014 Report Share Posted February 16, 2014 Hey so my water temp and oil pressure lights come on randomly so I pulled the instrument cluster today and found this, anyone think it's an issue? Quote Link to comment Share on other sites More sharing options...
Bean Posted February 16, 2014 Report Share Posted February 16, 2014 I can't see those causing an intermittent light, but I don't even have a cluster handy to know if those have been added or if they're supposed to be there. Poor grounds in the engine bay, and poor connections on sensors can also be a issue with false lights. Temp sensor on its way out could also be the culprit. Rabin Quote Link to comment Share on other sites More sharing options...
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