CASHEYE Posted January 19, 2016 Share Posted January 19, 2016 Hey guys, I've been talking to Heckler about this issue but I think I've reached the extent of my extremely limited ability to solve this issue and I don't want to keep bugging him about it. I've seen a few other threads on here and on other supra forums where after unplugging/plugging in various components on the dashboard, that the speedo cluster fails to illuminate when the headlights are turned on, but the solutions weren't clear. This problem extends to my rear fog light which is wired up in a similar method to Heckler's tutorial on the circuit boards he sells for the rear/fog mod. So far I've done the following; Checked the fuses in the drivers footwell - all are fine. Checked the dimmer/rheostat outside of the car in a circuit - this functions normally. Checked the fog light bulb outside of the car - this works fine. Checked the LEDs in the cluster outside of the car - these work. The selection lights for the gearbox (auto), the indicators and the highbeam lights all work as they should. The high, dipped, front fogs and sidelights all work fine. I've tried to bypass the dimmer using an LED to see if it would light up but it didn't. I've got to take it for an MOT test next week and I'm gonna need to get this fixed before then. Is there anything else I should try before I start paying someone else (which I'd rather not) to take a look at it. Thanks, Quote Link to comment Share on other sites More sharing options...
Ric Posted January 19, 2016 Share Posted January 19, 2016 have you tried a new dimmer? Quote Link to comment Share on other sites More sharing options...
CASHEYE Posted January 19, 2016 Author Share Posted January 19, 2016 No not yet, As far as I can tell it's working fine. when I removed it from the car it put it in a circuit with a battery and the fog bulb and it worked just fine. When I bypass it though, the cluster lights still don't come on.. Quote Link to comment Share on other sites More sharing options...
CASHEYE Posted January 20, 2016 Author Share Posted January 20, 2016 I finally found my multi meter this morning and I tested the dimmer/rheostat as it advises in the 'Body Electrical' part of the repair manuals section on here and there was a voltage drop when I turned the dial. Just to check the wires in the car again, I put the meter between the pins of the plug for the dimmer and there was no voltage. Any more ideas? Quote Link to comment Share on other sites More sharing options...
heckler Posted January 20, 2016 Share Posted January 20, 2016 I'd still try a dimmer... Quote Link to comment Share on other sites More sharing options...
np89 Posted January 20, 2016 Share Posted January 20, 2016 Do your sidelights work? Quote Link to comment Share on other sites More sharing options...
CASHEYE Posted January 20, 2016 Author Share Posted January 20, 2016 I'd still try a dimmer... I'll pm keron and see if he's got any. Do your sidelights work? And yes, side lights - all lights everything other than the ones that illuminate the dials and needles are working. Quote Link to comment Share on other sites More sharing options...
SupraP-Z Posted January 21, 2016 Share Posted January 21, 2016 When switching your headlight stalk to the on/off position, does the odometer reading disappear/reappear? Mine seems to be the same problem as yours with the added benefit of what ive just explained. Great Quote Link to comment Share on other sites More sharing options...
CASHEYE Posted January 24, 2016 Author Share Posted January 24, 2016 When switching your headlight stalk to the on/off position, does the odometer reading disappear/reappear? Mine seems to be the same problem as yours with the added benefit of what ive just explained. Great Nope, it's just the cluster lights that don't work. I bought a replacement dimmer from Keron but that hasn't solved the problem. Quote Link to comment Share on other sites More sharing options...
heckler Posted January 24, 2016 Share Posted January 24, 2016 Does the heater unit light up with the side lights on? Probably worth looking at the plug on the back guages... Quote Link to comment Share on other sites More sharing options...
CASHEYE Posted January 24, 2016 Author Share Posted January 24, 2016 Does the heater unit light up with the side lights on? Probably worth looking at the plug on the back guages... Yeah those lights work. All the other lights in the car work Headlights Headliner Heater controls Rear lights Boot light Quite literally every socket that has a bulb, works. Earlier I said that when I put my meter between the wires that plug into the dimmer switch, there was no voltage being shown. The engine and the headlight/sidelights were turned on. Surely that checking anything in the circuit that comes after the dimmer is pointless because there isn't any power getting to them anyway. I can only access a small portion of the wiring loom to check but everything is bound together so tightly that I doubt I've tugged on and broken a wire. Quote Link to comment Share on other sites More sharing options...
heckler Posted January 24, 2016 Share Posted January 24, 2016 With the side lights on, will the heater unit brightness change with the dimmer? Quote Link to comment Share on other sites More sharing options...
CASHEYE Posted January 24, 2016 Author Share Posted January 24, 2016 Nope. They just seem to stay on full brightness. Quote Link to comment Share on other sites More sharing options...
heckler Posted January 24, 2016 Share Posted January 24, 2016 And the rest of the lights? Auto spoiler etc? Can you see what voltage is at the dash lights? Quote Link to comment Share on other sites More sharing options...
CASHEYE Posted January 24, 2016 Author Share Posted January 24, 2016 Do you mean active spoiler? I don't have one. Umm right, these are the readings I've just taken (by cluster lights I mean the larger bulbs which your pcbs replace); Park selection light - 10.75v Fuel warning light - 10.68v Cluster lights - 00.00v Now the heater control LEDs are messed up anyway from the mod I was doing with different switches and lights BUT... the two LEDs for 'AUTO' read at 5.35v (these are not very bright at all) and the rest of the LEDs read at 2.02v (these are much brighter) The dimmer switch had no effect on the voltage of these readings for any of the contacts tested. Quote Link to comment Share on other sites More sharing options...
heckler Posted January 24, 2016 Share Posted January 24, 2016 Disconnect the heater unit, and see if the dash lights work... Quote Link to comment Share on other sites More sharing options...
CASHEYE Posted January 24, 2016 Author Share Posted January 24, 2016 Nope. Unplugged and still not coming on. Quote Link to comment Share on other sites More sharing options...
heckler Posted January 24, 2016 Share Posted January 24, 2016 At this point, I think your down to checking wires... Quote Link to comment Share on other sites More sharing options...
CASHEYE Posted January 24, 2016 Author Share Posted January 24, 2016 Sheeeeeeeet. Well I just went onto your website to look at how you wired up your pcbs. It says you can solder the wires directly to the circuit. But the picture for that part isn't showing up (on the pre and facelift versions). I guess it doesn't matter either way because the problem is further down the line so using something like your pcbs instead of the bulbs wouldn't work either right? Quote Link to comment Share on other sites More sharing options...
heckler Posted January 24, 2016 Share Posted January 24, 2016 Nope. Just remember the pcb's are polarity sensitive. Ok, another idea. 1) with lights on, the positive pin for the lights, to a an earth point on the chassis. 2) a con/resistance check between the negative pin for the lights and an earth point on the chassis. Quote Link to comment Share on other sites More sharing options...
CASHEYE Posted January 25, 2016 Author Share Posted January 25, 2016 Ok, By positive pin for the lights, are you referring to the spade connector at the bottom right hand corner of the cluster unit? The IG+ ? If so... I took a reading between that spade connector and the GROUND pin for the dimmer switch. During this whole process; The engine was turned ON The side lights were ON The Dimmer was connected and turned up (I turned the dimmer up and down and didn't see any change though out this test) The hazards button was connected The remaining info lights in the top panel were connected The heater controls were connected. The things that weren't plugged in were; Mirror folding switch Mirror adjusting switch Cigarette lighter Clock Radio Below I've included a picture of the back and I've labelled it (more for my reference). So.. on a fully charged battery... Readings between points and results are as follows; D - E = 13.6v Cluster and Dimmer D - 1 = 13.4v D - 2 = 13.4v D - 3 = 13.11v Then I measured between A8 and A9 as these pins appear to be feeding directly to the dial lights A8 - A9 = Didn't register voltage Then I rechecked the LED bulbs out of the car on a 12V battery and they still work. Indicators A6 - A7 = 10.7v / 0.79v All of the lights in F still work. I have no idea what 'G' is but it's fed from the wire on pin C10. What's the purpose of the connections on D/E? Couldn't I just wire up some lights directly to these spade connectors? (I'm slowly loosing my mind). Quote Link to comment Share on other sites More sharing options...
heckler Posted January 25, 2016 Share Posted January 25, 2016 G is a speed converter. Try the following..... with gauges fitted 1) Bypass the dimmer... connect GND to RTN... this will run the dash lights at 12v. 2) Bypass the dimmer, connect RTN direct to a chassis earth point. Really need to do con/resistance check between. (with gauges removed, eng off) 1)A9 and POS on the Dimmer plug (these should be connected together) 2)A8 and chassis - Again, should be connected together. A Voltage check between POS on the dimmer plug and a chassis ground point. Quote Link to comment Share on other sites More sharing options...
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