MPH Gauge ?

[AMC86Kid]

What is this part of the back of the gauge for ,  power? ground ? lighting? 

 

 

[Green Mesa XJ]

What the hell? Where is the printed circuit?

I’d have to dig out the electrical manual. it’s probably going to be a common ground, maybe.


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[Warren Mohler]

1 hour ago, Green Mesa XJ said:

What the hell? Where is the printed circuit?

This is a new one on me! I've worked on these since they came out and never saw direct wired gauge cluster

[eaglescout526]

He did away with the printed circuit and wired everything directly. Kinda impressive actually. 

[Green Mesa XJ]

Explains some of the trouble with gauges.

I’ve had trouble with the 84-86 printed circuits going bad. Peeling apart and degrading.
There were no replacements available for the printed circuits in the early 2000s i was able to get a spare printed circuit for the 87 or 88- 90 full instrument, Jeep was clearing it out for $12. I thought maybe it’d be close enough to work on the 86 cluster, it’s not. Eventually we bought 89-90 clusters to replace it and never had trouble with their printed circuits. Honestly that’s what I’d do here. As long as the dash harness is intact it’s plug and play. All of those gauges should come back to life accurately.

My first car I wired a cluster like this, original cluster didn’t have a factory tach and I wanted one, took a cluster out of another same era model and it didn’t plug in so I wired it directly, was not a good solution, worked for a bit then got lest dependable if I hit a bump.




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[Green Mesa XJ]

Here is the 1986 electrical book,
I’d have to look at the circuit but I think it’s a common ground most of the light and gauges share. But what’s in the book is not explicitly clear





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[AMC86Kid]

I will try to hook it up to a ground and see if that changes anything 

[Green Mesa XJ]

Find a cheap cluster out of a 1988-90 and throw that in, as long as your engine and dash harness are still factory/intact not cut up it will work.
It’s harder to find 84-early87 style like that one is and I never could find a good one when I search years ago .


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[Big_Mark]

Add on question, what is the magic to detach the speedo cable from the gauge? I  gather there is a clip to squeeze but from where or what angle? 

[Eagle]

5 hours ago, Big_Mark said:

Add on question, what is the magic to detach the speedo cable from the gauge? I  gather there is a clip to squeeze but from where or what angle? 

 

What year? It makes a difference.

[Green Mesa XJ]

I looked at the 89 cluster a little different but the way it’s routed it’s probably a ground. I can’t find a good breakdown of the c1 plug in the cluster. The cluster plug is the same 1984-90, one of my books ought to have it


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[Big_Mark]

On 5/30/2020 at 6:27 PM, Eagle said:

 

What year? It makes a difference.

Thanks for the response, it's an 1989, I have large hands and wrists so I may just drop the steering column to gain access.

[JustEmptyEveryPocket]

Did you find the bolt that holds the speedo cable by the driver side control arm? If you remove it from there you can push way more of the cable up into the cab, thereby making the backside of the cluster much easier to see and get to.

[Eagle]

20 hours ago, Big_Mark said:

Thanks for the response, it's an 1989, I have large hands and wrists so I may just drop the steering column to gain access.

 

Your speedo cable is attached with a white, nylon clip. On two sides there are tabs that you squeeze together, allowing the cable to slide off the head.

[Big_Mark]

Thanks for the tips "J.E.E.P." and Eagle I should be able to get it out easier with these tips.