Grounding help 74 CJ5

[CJ 74]

A little confused about grounding a 74 CJ5 , just bought this CJ. The negative post of a new battery and cable install has a wire that's not connected to anything. I want to get a good ground to the dash, the fuel and temp gauges don't work. One site said this can't be connected directly and the other site says it can be. I noticed when the lights are on the speedometer, temp and fuel gauges don't light up. Any help would be greatly appreciated.

 

[Hedgehog]

What was the logic leading to the thought that the unused ground wire on the post clamp can't be used? A ground is a ground is a ground. I'd have no trouble running a wire to the dash. Maybe not to something that draws a LOT of amperage, but for gauges and other low power users, why not?

 

[gr8dain]

What was the logic leading to the thought that the unused ground wire on the post clamp can't be used? A ground is a ground is a ground. I'd have no trouble running a wire to the dash. Maybe not to something that draws a LOT of amperage, but for gauges and other low power users, why not?

Wondered the same thing. I have a wire from the neg terminal to a grounding block under the dash. Then lots of wires from that to other items in the cab. The glass tub made grounds a real problem with my CJ. Fun times.

 

[CJ 74]

Not sure why the grounding wire is not used, just bought this Jeep. Looks like someone tried to fix the gauge issues before, extra parts came with this and one was a fuel sending unit. I am hoping the problem is just a bad ground. So I should be able run a wire directly from the negative post to the firewall or dash and be ok? Thanks for the replies.

 

[gr8dain]

If you do, then the firewall or dash will be grounded for sure.

 

[Lumpy Grits]

Mount it to the firewall. Use a through bolt & nut, and not just a sheet metal screw.
Run a dedicated lead from the dash panel to the newly mounted battery GND.
Attach the main GND from the battery to the top bolt of your starter.
Make sure a GND strap goes from the engine to the frame.
Use external starwashers as they 'bite' into the metal to maintain contact.
Coat these GNDs with battery terminal spray.
Good luck,

LG

 

[CJ 74]

Thanks for all the help! Bought a ground strap and 10g wire this week and plan on working on the jeep this weekend.

 

[Hedgehog]

Most after market battery cables come with that extra wire. If you need it, it's there, if not do harm done. If you use it remember to have enough extra wire to remove the battery clamp and move it around.

 

[CJ 74]

Thanks for all the help! Ran the wires as suggested, fuel gauge started working as soon as the dash was grounded but still no lights on the dash. Temp gauge is still not working tried the 12 volt test light on the temp sensor wire and had no power, also checked the sensor itself nothing. Traced the wire up the wiring harness to the connector and tested the terminals there was no power on any of the wires coming through that harness. Any ideas?

 

[JeepCJ5]

I had the exact same problem and also assumed it was a ground issue, but it was the switch. Try turning the headlight dimmer switch left and right and see if the lights flicker at all.

In my case, I had one specific spot where the lights came on. I swapped out a new switch and the dash lights work perfectly now.

 

[j6824]

Thanks for all the help! Ran the wires as suggested, fuel gauge started working as soon as the dash was grounded but still no lights on the dash. Temp gauge is still not working tried the 12 volt test light on the temp sensor wire and had no power, also checked the sensor itself nothing. Traced the wire up the wiring harness to the connector and tested the terminals there was no power on any of the wires coming through that harness. Any ideas?

You sure the jumper wire off the fuel gauge is there with good connection? I'd check sender wire, too...often they're cut or disconnected in favor of a mechanical replacement.

I'd bet that the sender is bad, especially if its original

Gauge might be,too...

Best diagnostic around : civilianjeepinfo.com

 

[CJ 74]

No luck with the switch even tried them all and tried moving some wires to see if there was a loose connection. Thanks though. Sure will try checking the fuel gauge jumper wire Saturday. I looked behind and under the dash, looks like someone has tried fixing the lights before, some of the light socket wires have been cut and replaced with aftermarket sockets. Not convinced they are getting any power going to try testing them Sat. Appreciate all the help!

 

[Turbogus]

This here thread I've referred to again and again and it's kept me out of trouble;
Been reading the good book of JeepHammer! - JeepForum.com

 

[Lumpy Grits]

PLZ follow what JH sez.
Sure has helped me over the years.


LG

 

[CJ 74]

Really good info. Thanks guys.

 

[Turbogus]

Even if the CVR has a tight connection, if there's any oxidation, it could lead to erratic results.