Shane Posted March 11, 2012 Share Posted March 11, 2012 Finally completed the idiot light to gauge conversion. How do I check to make sure that the speedometer is accurate as well as the tach and fuel gauge? Any advice is appreciated. Link to comment Share on other sites More sharing options...
johnnyc Posted March 11, 2012 Share Posted March 11, 2012 Check the speedo with a GPS unit. You should be idling at about 500-600 RPM. And you should have taken note of the fuel level before you took the old cluster out. Link to comment Share on other sites More sharing options...
Shane Posted March 12, 2012 Author Share Posted March 12, 2012 Check the speedo with a GPS unit. You should be idling at about 500-600 RPM. And you should have taken note of the fuel level before you took the old cluster out. :no: No, no... Don't get me wrong I did that and it is good as far as I could see, but I was letting the gas run down to see when the light comes on. The needle is sitting on E, but the light has yet to come on. Like I have stated in alot of my post I am not a mechanic :wrench: and do not claim to be one, however, :idea: I am very logical and exercise common sense :rotf: .. Thanks alot for the advice. If it is off, how do you adjust it Link to comment Share on other sites More sharing options...
cruiser54 Posted March 12, 2012 Share Posted March 12, 2012 Does your cluster have the low fuel light in it, or a bulb in that socket? Those low fuel lights usually come on at about 1/8 to 1/16 of a tank. Link to comment Share on other sites More sharing options...
ParadiseMJ Posted March 12, 2012 Share Posted March 12, 2012 AFIK the only way to adjust the mechanical speedo is to have the proper speedo gear in the t-case to account for tire size. If you have larger tires or changed the gearing or t-case it is probably off. I have 31's and my speedo is about 9-10% off. I just adjusted in my head (using logic and common sense, and a GPS of course). If my speedo reads ~65...the GPS says I'm going ~71. I have wanted to swap out the speedo gear, but I'm on to other priorities, and I'm lazy. Link to comment Share on other sites More sharing options...
Shane Posted March 15, 2012 Author Share Posted March 15, 2012 I filled the tank today and the hand only went to a little over 3/4. Along with that my speedometer reads about 7 mph less than GPS. Can I just simply pull the needles off and put them where they should be? Another question my oil pressure gauge starts out at 40. As I get higher in the gears it goes down to almost 20; is this correct? It runs good. If not how do ya fix it.. Basically the question is can I pull the needles on the gauges to adjust them to being accurate? Does the oil pressure reading sound correct? Link to comment Share on other sites More sharing options...
Shane Posted March 15, 2012 Author Share Posted March 15, 2012 I filled the tank today and the hand only went to a little over 3/4. Along with that my speedometer reads about 7 mph less than GPS. Can I just simply pull the needles off and put them where they should be? Another question my oil pressure gauge starts out at 40. As I get higher in the gears it goes down to almost 20; is this correct? It runs good. If not how do ya fix it.. Basically the question is can I pull the needles on the gauges to adjust them to being accurate? Does the oil pressure reading sound correct? Is this possiable??? Link to comment Share on other sites More sharing options...
Backdraft Posted March 15, 2012 Share Posted March 15, 2012 No. Link to comment Share on other sites More sharing options...
chastings Posted March 16, 2012 Share Posted March 16, 2012 The speedo reading wouldn't have changed with the installation of your new gauge cluster, if its reading fast now, it was reading fast with the old one too. I'm running 235's on my comanche and it always registers 4 mph too slow (I just accept the fact that I'm driving 4 mph faster than my speedo shows, or you can change speedo gear) Does the oil pressure drop to 20 only in higher rpms? Seems strange.... When I did my swap my oil pressure at cold read 20 idle and 60 when driving. Once it warmed up it always read 20 though. I swapped sending units with my cherokee and all of a sudden the gauge would read correct at all temperatures (always 20 @ idle and 60 when driving). I went to return the faulty sending unit back to napa and they realized it was the wrong part number. It looked correct and was similar but was not calibrated the same as the correct unit and showed a huge discrepancy only at operating temperature. Perhaps this is part of your problem? Not sure about the fuel gauge, did it work properly with your old cluster? Almost sounds like the float is sticking in the tank. I was hesitant about the light coming on in my fuel gauge, but it does work. The needle was literally buried at the empty mark before it came on. I had a spare can of gas in the back and nothing but time. Link to comment Share on other sites More sharing options...
Shane Posted March 16, 2012 Author Share Posted March 16, 2012 The oil gauge may reach 50. On the highway it drops below 40 and then steadies itself around 25 until I give it gas. The oil is good and seems to be getting the oil pressure. The sending unit they gave me is in the shape of a bell (best description). Any one know how tho check the ooil pressure? I'll check the part tomorrow to see if its right. Let's say every thing is good; is it possiable to adjust the gauges???????? Link to comment Share on other sites More sharing options...
Shane Posted March 16, 2012 Author Share Posted March 16, 2012 Another question? Seeing how you never know the people in which you get a part from or what they have done to it; is it possiable that the needles are pushed on too far? Just an idea, thought I would ask. Link to comment Share on other sites More sharing options...
chastings Posted March 16, 2012 Share Posted March 16, 2012 Your best bet is to buy a mechanical aftermarket oil pressure gauge and run it for a bit to get a baseline. A good rule of thumb is 10 psi for every 1000 rpm. I'm almost certain there is no way to adjust the gauges (but I've been wrong before). Link to comment Share on other sites More sharing options...
Shane Posted March 17, 2012 Author Share Posted March 17, 2012 Your best bet is to buy a mechanical aftermarket oil pressure gauge and run it for a bit to get a baseline. A good rule of thumb is 10 psi for every 1000 rpm. I'm almost certain there is no way to adjust the gauges (but I've been wrong before). So the oil pressure reading 20 psi isn't a bad thing??????? I have the oil sending unit that looks like a bell. Does yours look like that? Got it from auto zone. If yours don't look like that, then what does it look like? Thanks alot man for all your help... Link to comment Share on other sites More sharing options...
Shane Posted March 17, 2012 Author Share Posted March 17, 2012 Your best bet is to buy a mechanical aftermarket oil pressure gauge and run it for a bit to get a baseline. A good rule of thumb is 10 psi for every 1000 rpm. I'm almost certain there is no way to adjust the gauges (but I've been wrong before). So the oil pressure reading 20 psi isn't a bad thing??????? I have the oil sending unit that looks like a bell. Does yours look like that? Got it from auto zone. If yours don't look like that, then what does it look like? Thanks alot man for all your help... :dunno: Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 17, 2012 Share Posted March 17, 2012 The oil gauge may reach 50. On the highway it drops below 40 and then steadies itself around 25 until I give it gas. The oil is good and seems to be getting the oil pressure. The sending unit they gave me is in the shape of a bell (best description). Any one know how tho check the ooil pressure? I'll check the part tomorrow to see if its right. Let's say every thing is good; is it possiable to adjust the gauges???????? You can calibrate the gauges, but you need specialized test equipment. DO NOT pull the needle on a gauge to make it read what you think it should read. You bought the oil pressure sender from Autism Zone, right? What is the part number of the sender you bought? Shaped "like a bell" is correct, but there are many oil pressure senders shaped like a bell with different HI-LO ohm ranges. Link to comment Share on other sites More sharing options...
Shane Posted March 17, 2012 Author Share Posted March 17, 2012 The oil gauge may reach 50. On the highway it drops below 40 and then steadies itself around 25 until I give it gas. The oil is good and seems to be getting the oil pressure. The sending unit they gave me is in the shape of a bell (best description). Any one know how tho check the ooil pressure? I'll check the part tomorrow to see if its right. Let's say every thing is good; is it possiable to adjust the gauges???????? You can calibrate the gauges, but you need specialized test equipment. DO NOT pull the needle on a gauge to make it read what you think it should read. You bought the oil pressure sender from Autism Zone, right? What is the part number of the sender you bought? Shaped "like a bell" is correct, but there are many oil pressure senders shaped like a bell with different HI-LO ohm ranges. Part # PS133. All advice is appreciated... Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 17, 2012 Share Posted March 17, 2012 Part # PS133. All advice is appreciated... PS133 is the switch for the MJ/XJ oil pressure idiot light. Bring it back. You need Autismzone p/n CP7577 (called a sender / variable resistor) for your oil pressure gauge. http://www.autozone.com/autozone/accessories/1Sunpro-1-8-in-NPT-oil-pressure-sender-with-1-4-in-NPT-adapter-for-electrical-oil-gauges/_/N-269r?itemIdentifier=87626_0_0_ Link to comment Share on other sites More sharing options...
Shane Posted March 17, 2012 Author Share Posted March 17, 2012 Part # PS133. All advice is appreciated... PS133 is the switch for the MJ/XJ oil pressure idiot light. Bring it back. You need Autismzone p/n CP7577 (called a sender / variable resistor) for your oil pressure gauge. http://www.autozone.com/autozone/accessories/1Sunpro-1-8-in-NPT-oil-pressure-sender-with-1-4-in-NPT-adapter-for-electrical-oil-gauges/_/N-269r?itemIdentifier=87626_0_0_ Am I right in assuming that this would cause the gauge to read incorrectly???? I like the autism zone :rotfl2: Any ideas as to my fuel gauge light not coming on at E? Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 17, 2012 Share Posted March 17, 2012 First question: Of course. Second: Check the bulb. :cheers: Link to comment Share on other sites More sharing options...
Shane Posted March 17, 2012 Author Share Posted March 17, 2012 Hey, thanks alot buddy!!!!! :cheers: Where did ya get the column shift indicator that you have? Link to comment Share on other sites More sharing options...
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