Hey guys, When i ordered my truck i ordered just about every electical option with the exception of the overhead trip computer,keyless entry and heated seats. I have the map light set up. My question is, does anyone know if the harness is already there on a SLT or is something that will need to be wired. Short of pulling down the overhead,i can't seem to find out from the parts dept. I have installed other options and have found that the wireing harness was already there. Just want to be sure before i order the trip computer. Thanks in advance TGCTD

 

The wiring harness is already installed behind the headliner. You will have to shoot the circuits and get the modules for the power center under the hood. But, why waste your time and money? I have yet to see one that worked worth a hoot!

 

My truck has the computer, and I agree with RCW--it's not very accurate. I can see why the "MPG guesser," as someone on here called it, is by nature an inexact tool, but even the outside thermometer seems a bit weird--it consistently reads 5-10 degrees high when I first start the truck. Then it slowly comes down to the right temp. Once it's on, though, that's my favorite display in winter so I know when to start considering whether the roads are about to freeze or not. I do wish it had a chime like my M3 that would go off when it hit 32 degrees F.

 

I thought about doing the same thing. But after driving my wife's Grand Cherokee for a few days while we were on vacation I didn't find the mileage guesser to be all that accurate and decided against it. I do have to add that the thermometer and compass seemed to be more accurate than the mileage though.

 

My 2001 "guesser" has been less than 1 mpg off when I have checked against it. The truck is stock though. We had a Saab with I think they called it an "Information Center" that worked awesome. It had avg. MPG, avg. MPH, distance to destination, you could set the time you wanted to get somewhere and distance and it would set a pace to get there at that time. It also had a switch to turn off all gauges except the speedo (it was really easy on the eyes at night). It would turn on the gauge light if it was getting out of normal range. If you revved into the red zone the tach would come on, low on gas the fuel gauge would come on, etc. The only quirk was that the thing would chime at 37 degrees to warn about a freezing road.

 

[quote author=wheezer link=board=5;threadid=9534;start=0#91868 date=1042553572]<br>The only quirk was that the thing would chime at 37 degrees to warn about a freezing road. <br>[/quote]<br><br>Maybe water freezes at a higher temp in Sweden.

 

If your just looking for the compass and the temp. check into one of these mirrors;<br><br>Electronic Rear View Mirror<br><br>Here's one that Northern Tool carries;<br><br>Northern Tool's mirror<br><br><br>Here is one more company that has them. (this mirror is my favorite)<br><br>Mirror with map lights<br><br>Hope that helps. ;D<br><br>DB<br><br>

 

RCW, Thanks for the info. If the harness is already up there,it should be a plug in operation.As far as modules according to the parts listing the display is the module.The ambient temp switch should slao be there if the harness is. As far as the inaccuracy,i know the temp reads the last temp at key off and does not register the accurate temp until after you move the vehicle because you &quot;store&quot; the last under hood temp,because of where the ambient temp sensor is located.The MPG &quot;guesser&quot; as is has been called takes info from the fuel level sensor and the odometer and is only as accurate as those guages. Compass accuracy is dependent on the calibration of your inclination and must not be performed under power lines. So i would imagine if the dealer did not calibrate the compass from the factory it would never read right in a different location from manufacture. Anyhow thanks for the input TGCTD

 

[quote author=TGCTD link=board=5;threadid=9534;start=0#92732 date=1042727175]<br>As far as the inaccuracy,i know the temp reads the last temp at key off and does not register the accurate temp until after you move the vehicle because you &quot;store&quot; the last under hood temp,because of where the ambient temp sensor is located.<br><br>The MPG &quot;guesser&quot; as is has been called takes info from the fuel level sensor and the odometer and is only as accurate as those guages.[/quote]<br><br>Now that info solves a couple of mysteries for me, particularly the temp deal. On the MPG guesser, the question then becomes whether the fuel-level sensor input it gets is more accurate than whatever feeds the fuel gauge, or if the fuel gauge is somehow programmed to calculate pessimistically, because at 1/8 tank on the gauge I can only put in about 27 gallons... That would translate to a 64 gallon tank. ???

 

Just to let anyone know who is interested,i have done some research and the harness is not there. There is a base overhead console and a premium console. The base overhead console does not come with the correct harness for mini-trip computer op and the ambient sensor or the section of harness for the ambient sensor. anyone interested,i have more information,such as part numbers and circuit connections for the harness to be installed. Tony

 

I asked Tacoma Dodge about installing one. They said the wiring harness etc. is not there. They've done a couple and they never work out - something always melts or puffs little smoke *****. Also, from them, the I.C. board that fits in the overhead console is $700.<br><br>I've been looking at aftermarket units that can be re-calibrated for accuracy after bombing...<br><br>http://go.jeep-xj.info/HowtoTripC.htm<br><br>http://www.kel.mtl.pl/_enginfo.htm<br><br><br><br>

 

Melting &amp; puffs of smoke? ??? I have researched the wireing diagrams and the pin connectors. It is only a matter of unplugging the base harness and installing the premium overhead harness. How can anyone smoke wires doing this? What is involved is to remove the head liner A,B,&amp; C pillars,left side kick panel and knee bolster to gain access. You will need to unplug the C-3 connector and remove the original &quot;base&quot; harness. If you have clearance lights,it is part of this harness. The new harness comes with a 12 pin connector at the overhead console,instead of the 3 pin that is there now. The premium harness plugs into the C-3 connector inplace of the base harness and the remaining connector plugs into the C 358 harness. The C-358 connector carries the BUS signals from the PCM to calculate items like distance to empty,fuel mileage etc. The compass is all internal,and the ambient temp is retrieved from under the hood. You will need to purchase the harness that runs under the hood from the C-114 connector that is near the the under hood light.(if you have one). You will need to purchase the ambient temp sensor and mount it next to the hood release on the under side of the hood. The harness from the C-3 connector to the overhead console is ordered with or without clearance lights.(depending if you have them)and will also come with the two connectors for vanity mirrors if you want to install them. Retail cost is probably in the neighborhood of $ 500.,and that is if you do the installation yourself. My cost,with my employee discount is in the neighborhood of $ 250. so to me it would be worth it. As far as accuracy,your fuel tank capacity needs to be programmed into the mini-trip computer to have an accurate Dis to empty . The fuel mileage is based on fuel tank level and odometer received over the BUS, so anyone who has inaccurate readings should check their programming. As far as the compass,variance also has to be programmed into the computer by geographic location to give a true reading of N. Temp only updates after 3 secs. of driving at 30 mph after key on. I don't think bombing is going to change the accuracy of the mileage calculator,but may read lower than you would like. TGCTD

 

I did have my overhead trip computer replaced under waranty back in 99 because it would show all 888888's. When I signed the invoice it had over $1,000 dollars worth of parts on it, along with 9.5 hours of labor. Sure glad DC paid for that one.<br><br>DB

 

TGCTD,<br><br>Gotta love it when owners know more about their rig than the dealer . Based on the dealer's experience, I'd decided to go with aftermarket, but I'm rethinking this since the factory unit would look a whole lot better! Have you done this and had it work? Do you know how to re-program the mileage accuracy? Seems like all of the guys I've talked to and the posts I've read indicate that the computer indicates better mileage than actual because it's measuring injector signal and with the larger injectors, the signal measured is of shorter duration. I would think a lot of guys would like to know how to correct this. If you can help out here, I'm going to replan my trip to the wrecking yard for some wiring harnesses and trip computer.<br><br>Thanks<br>Rob

 

Hate to disappoint you Rob,but i am a Gold certified Chrysler tech at a Dodge dealership. I guess when i first asked the questions on the harness being present i was trying to short-cut any research. : Armed with a factory service manual , i found what was necessary to get the job done. AS for accuracy compass calibration it can be done without any special equipment.However fuel tank capacity will need to be calibrated with a DRB,or similar scanner that has the capabilities. As for fuel mileage,the average MPG calculator takes it's information from the odometer and fuel level sensor (why fuel tank capacity is important ),and the mini-trip computer sends this information from the PCM via the Bus i identified as the C358 connector. For instantaneious MPG i am not positive exactly what the PCM is reading to optain that ???,but i would speculate that it would get that information from the MAP sensor and the APPS sensor. The compass is all internal to the mini-trip computer,and the ambient temp comes from a two wire sensor under the hood. Although i don't have my parts yet i have no dought at all that that the install will work. Hope this helps. Tony ;D