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Unread 11-15-2013, 02:48 PM   #1
simple
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1978 CJ7 
 
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Rewire 1978 cj7 because gauges don't work?

I've owned my 1978 cj7 renegade for a couple of months now. The only gauges that work are the speedometer, blinker indicators, and the high beam indicator. My question is would it be better to get new gauges and rewire everything or continue the splice jobs that are all over the place under the dash and search for what wrong under there?

How difficult is a complete rewire and which harness is the best?

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Unread 11-15-2013, 03:20 PM   #2
danmc77
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I'm still down to the frame on my 78, so i haven't had to tackle the wiring yet, but here's my two cents:

a new chasis harness (complete vehicle) is going to run about $500 give or take, so you have to weigh the amount you will spend vs the realistic ability to repair the old one. Wires can and do corrode inside the insulation, so bad spices aren't always the culprit. But, if you decide to repair vs replace, I highly recommend taking the time to obtain a nice, detailed wiring schematic, remove it from the vehicle and go through and eliminate unnecessary wires and solder all splices and heat-shrink wrap them. No crimps anywhere that aren't ultimately soldered.

I re-wired an 89 Ramcharger with a Painless chassis harness and it took me a few days of free time to figure out all the switches, terminals, and plugs. Although, that was a universal system, and I think they have a Jeep-specific one, so it might be a bit easier.

Test the gauges first, than the wire terminals on the harness for the gauges and maybe ultimately the sending units (gas, oil, etc.) to find why they're not working. But I agree - if you have a crap-load of crimps and splices - look to do a larger repair just for safety and reliability - even if it's not the cause of the gauge failure.
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Unread 11-15-2013, 03:27 PM   #3
danmc77
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BTW - if you do it right, soldering wires is super easy and it makes you feel good to have a nice, professional result when you do it right. Not to mention they are more reliable splices and terminations.

Get a hold of wire crimp connectors - bare if possible; or remove the colored plastic sleeve. tedious, I know - and "tin" them. heat the terminal with the iron, and let the solder melt onto it. Then tin the actual wire too. Now you can crimp the terminal to joint or terminate the wire, then solder it. With both tinned, just heat them up and you'll have a nice clean soldered joint. add solder if needed. use heat shrink to insulate.

I'm no expert, but I did this whole process on my 68 Charger and it took a while, but I redesigned the charging system and dash harness and it's worked flawlessly for the last 5 years.
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Unread 11-15-2013, 03:48 PM   #4
atopi3
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Iam doing a 88 YJ right now and dammc is right in what he is saying the painless harness is the way to go.I would like to add: Check the fuse then pull that fuse and check that you got power on the termanial prongs. Those prongs get week and durty under there you may need to squeze them together a little bit for a good connection. Good luck Happing jeeping
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Unread 11-15-2013, 04:13 PM   #5
keithcj-7
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Quote:
Originally Posted by atopi3 View Post
Iam doing a 88 YJ right now and dammc is right in what he is saying the painless harness is the way to go.I would like to add: Check the fuse then pull that fuse and check that you got power on the termanial prongs. Those prongs get week and durty under there you may need to squeze them together a little bit for a good connection. Good luck Happing jeeping
X2 on the fuse block prongs rust was the culprit for me on my 78 renegade.
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Unread 11-15-2013, 04:41 PM   #6
jeepwhore
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Given the nature of CJ gauges to quit working, re-wiring might be akin to chopping off your arm to trim a fingernail.

Unless the harness is completely hacked and you're sure it's not just burnt gauges then go for it, but it might be time and money put to better use elsewhere.
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