Matt Wood Posted July 2, 2020 Share Posted July 2, 2020 Hi Guys, I decided to take the plunge and spend the money on a cluster with a tach and have it shipped over to the uk (Trust me it cost far too much!!!!!) I tested the tach in the truck and it worked great, now i've 'restored it' and put it in i've gone to use the lights and turn signals and none of it works... my question is... are the circuits different for an 80s truck and and 85 truck? mine is an 85 and has all the proper gauges just no tach. i assumed it would just plug and play since i dont have dummy lights. When i turn on the lights the high beam light comes on VERY dim and then gets bright when i click the high beam button. thats the only light that seems to 'work' I have compared the circuit boards and i cant see a real difference, is there a resistor that they added / changed or is there something more sinister happening with the voltage regulator on the cluster? Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 2, 2020 Share Posted July 2, 2020 Matt - Yes, there were some changes for some of 1980 trucks vs the 1981 - 86 trucks. The differences I remember were for the warning lights in the cluster. They were in different places. I just looked at the 1980 EVTM and I cannot tell from it what was changed because the circuits are still the same, they just put things in different places. I think there's a post on FTE about this, and I can look. But do you really have a 1980 instrument cluster? Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 2, 2020 Share Posted July 2, 2020 Matt - Yes, there were some changes for some of 1980 trucks vs the 1981 - 86 trucks. The differences I remember were for the warning lights in the cluster. They were in different places. I just looked at the 1980 EVTM and I cannot tell from it what was changed because the circuits are still the same, they just put things in different places. I think there's a post on FTE about this, and I can look. But do you really have a 1980 instrument cluster? Check this out: https://www.ford-trucks.com/forums/1028455-howto-81-86-gauge-cluster-in-80-model-gauge-models-only.html#post9810375 Link to comment Share on other sites More sharing options...
Matt Wood Posted July 2, 2020 Author Share Posted July 2, 2020 Matt - Yes, there were some changes for some of 1980 trucks vs the 1981 - 86 trucks. The differences I remember were for the warning lights in the cluster. They were in different places. I just looked at the 1980 EVTM and I cannot tell from it what was changed because the circuits are still the same, they just put things in different places. I think there's a post on FTE about this, and I can look. But do you really have a 1980 instrument cluster? well i cant confirm its form an 80 but the markings on the cluster have lead me to assume its from an 80 truck, here is a picture of the PCB, i may end up creating my own wiring for the tach and using the working PCB for now... Link to comment Share on other sites More sharing options...
Matt Wood Posted July 2, 2020 Author Share Posted July 2, 2020 Check this out: https://www.ford-trucks.com/forums/1028455-howto-81-86-gauge-cluster-in-80-model-gauge-models-only.html#post9810375 Thanks for the link! From his description "80 cluster has a green PCB" i now question if i have one from an 80.... Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 2, 2020 Share Posted July 2, 2020 Thanks for the link! From his description "80 cluster has a green PCB" i now question if i have one from an 80.... What color are your two printed circuits? The odd one is the 1980 one. So you should be good with the other one. But your original printed circuit doesn't have the tach connections? If so, you could put eye terminals under the nuts and wire into the harness the other side of the connector. It would be a pain, but it has been done. Link to comment Share on other sites More sharing options...
82F150I6 Posted July 3, 2020 Share Posted July 3, 2020 A while back I installed a '80 cluster with tach into my '82. It was a drop-in replacement except that the '80 cluster would blink the Oil warning light whenever I signaled a right turn. I recently installed the factory tach into the original '82 cluster (using the eyelet method others mentioned), put that into the truck and things are back to normal. AFAIK, the cluster regulator supplies voltage to the Fuel, Water Temp, and Oil Pressure gauges. If the gauges work then it's likely the regulator is OK. Make sure the harness connector is securely locked to the rear of the instrument cluster. I didn't when I reinstalled the '82 cluster and had a moment of mild panic when I started the truck and none of the lamps or gauges worked. Link to comment Share on other sites More sharing options...
Matt Wood Posted July 4, 2020 Author Share Posted July 4, 2020 What color are your two printed circuits? The odd one is the 1980 one. So you should be good with the other one. But your original printed circuit doesn't have the tach connections? If so, you could put eye terminals under the nuts and wire into the harness the other side of the connector. It would be a pain, but it has been done. so an update to the saga everyone, i pinned out all three clusters i have (one of which being a green PCB cluster from a 1980s truck). everything seemed fine although the resistance was a little on the high side on the cluster giving me issues (the one with the tach) so i used a fibreglass pen to clean up all the copper contacts on the PCB and also all the terminals on the bulb holders, doing all this got only the right hand indicator working. i then decided to change every light bulb and to my surprise it fixed all the lights, they all now switch on! I had looked at every bulb and they all looked intact so who knows why they weren't working.. The issue i was having with the lights and high beam was caused by the ground on the drivers fender by the side light.... dont ask me why the cluster needs that ground at all but that was the cause of that... Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 4, 2020 Share Posted July 4, 2020 so an update to the saga everyone, i pinned out all three clusters i have (one of which being a green PCB cluster from a 1980s truck). everything seemed fine although the resistance was a little on the high side on the cluster giving me issues (the one with the tach) so i used a fibreglass pen to clean up all the copper contacts on the PCB and also all the terminals on the bulb holders, doing all this got only the right hand indicator working. i then decided to change every light bulb and to my surprise it fixed all the lights, they all now switch on! I had looked at every bulb and they all looked intact so who knows why they weren't working.. The issue i was having with the lights and high beam was caused by the ground on the drivers fender by the side light.... dont ask me why the cluster needs that ground at all but that was the cause of that... Congrat's, Matt! That was a very thorough process, and you fixed several problems. Maybe even some you didn't know you had. And, since that pub you take pics in front of is probably open for the first time in quite a while, what are your plans? Link to comment Share on other sites More sharing options...
Matt Wood Posted July 4, 2020 Author Share Posted July 4, 2020 Congrat's, Matt! That was a very thorough process, and you fixed several problems. Maybe even some you didn't know you had. And, since that pub you take pics in front of is probably open for the first time in quite a while, what are your plans? funny you say that we went to a differnt pup this evening to celebrate my mum's birthday! Had a lovely social distanced meal. That pub you speak of incidentally opened at 6am this morning for fresh pints! as did every pub in England, i can't say i went for that early morning pint however Link to comment Share on other sites More sharing options...
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