Guage accuracy question

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kansasboy001
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Guage accuracy question

Postby kansasboy001 » Thu Apr 05, 2018 9:38 am

My 83's stock guages are horribly inaccurate even with the voltage regulator mod. I've been thinking of swapping the entire dash from an 86 to get the newer guages. Or save up for a Dakota. Are the 86+ guages and senders actually somewhat accurate?

Thanks
1983 Cherokee Laredo. 360/ 727/ np229/ Rochester quadrajet/ Msd ignition

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babywag
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Re: Guage accuracy question

Postby babywag » Thu Apr 05, 2018 10:18 am

Not worth the effort to swap the whole dash just for gauges. Newer are more accurate, but probably still not what you're after?
Go aftermarket like dakota digital, or roll your own gauges w/ an overlay like many have done.

The stock gauges can be calibrated to be more accurate, but it takes effort to check/repair all the wiring, and replace the CVR.
They still won't be great though.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

letank
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Re: Guage accuracy question

Postby letank » Thu Apr 05, 2018 10:50 am

As Tony said, our gauges are neither precise nor accurate, but give you an idea of what is happening.

I am pretty pleased with the CVR mod on the 85. The 74 is still running the OEM cvr and has been fairly reliable, except for the gas gauge.

Recheck your ground, add extra ground wiring from battery to engine, from engine to frame and especially frame to gauge cluster*, ignition module to engine and frame.

* I added an extra wire from the cluster common screw ground to the heater control ground and one to the mount behind the cluster.

Do not forget the ammeter bypass as well.
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (226 Kmiles... the running test lab)
See Engine bits and Fuel and brake lines, and Body work

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kansasboy001
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Re: Guage accuracy question

Postby kansasboy001 » Thu Apr 05, 2018 11:08 am

babywag wrote:Not worth the effort to swap the whole dash just for gauges. Newer are more accurate, but probably still not what you're after?
Go aftermarket like dakota digital, or roll your own gauges w/ an overlay like many have done.

The stock gauges can be calibrated to be more accurate, but it takes effort to check/repair all the wiring, and replace the CVR.
They still won't be great though.


Money is the big thing pushing me towards dash swap. I can get a whole 86 j20 for less than a Dakota. As far as the wiring goes my general harness is in really good shape and I've ran new ground for fuel sending unit. Done the voltage regulator mod as well. I assume the newer guages at least are consistent in their readings? Also new dash has better wiper and hvac controls right?
1983 Cherokee Laredo. 360/ 727/ np229/ Rochester quadrajet/ Msd ignition

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babywag
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Re: Guage accuracy question

Postby babywag » Thu Apr 05, 2018 11:25 am

Yes, but it's more than just slapping in dash. There are several differences in the wiring harness that will need to be addressed.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

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kansasboy001
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Re: Guage accuracy question

Postby kansasboy001 » Thu Apr 05, 2018 1:31 pm

babywag wrote:Yes, but it's more than just slapping in dash. There are several differences in the wiring harness that will need to be addressed.


Obviously ammeter delete would be the big change in wiring. But other than that isn't it just different connectors and connector locations?
1983 Cherokee Laredo. 360/ 727/ np229/ Rochester quadrajet/ Msd ignition

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babywag
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Re: Guage accuracy question

Postby babywag » Thu Apr 05, 2018 1:42 pm

All switches & connectors, etc. are different.
@ minimum you’d need to graft those in, and modify any wiring as needed.
The whole HVAC harness is wired differently, you’d need that wiring as well to use new stuff.
different gauge cluster wiring, different sending units for gauges.
Would need wiper module & associated wiring.

Whole lotta work for small improvement.
If you prefer look of newer dash then swap everything including dash harness, and probably still have mod some stuff.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

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kansasboy001
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Re: Guage accuracy question

Postby kansasboy001 » Thu Apr 05, 2018 2:11 pm

Newer ac is happening anyways. Regardless of dash swap. Mine didn't have ac from factory and this j20 is the only fsj remotely close to me. If I don't swap the dash not sure what I'm gonna do for the controlls. Haven't been able to find anyone that's used other controls for the ac than the factory ones.
1983 Cherokee Laredo. 360/ 727/ np229/ Rochester quadrajet/ Msd ignition

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babywag
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Re: Guage accuracy question

Postby babywag » Thu Apr 05, 2018 4:14 pm

Then swap dash and whole harness, make it easier on youself.
Swap engine harness too, be less work than all little changes.

I’d swap column as well.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

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kansasboy001
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Re: Guage accuracy question

Postby kansasboy001 » Thu Apr 05, 2018 4:27 pm

babywag wrote:Then swap dash and whole harness, make it easier on youself.
Swap engine harness too, be less work than all little changes.

I’d swap column as well.

I was thinking that but how would I do the tailgate and rear defrost wiring? The j20 fuse box doesn't have the wiring for them. Other than that it'd pretty much be a bolt across swap
1983 Cherokee Laredo. 360/ 727/ np229/ Rochester quadrajet/ Msd ignition

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Stuka
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Re: Guage accuracy question

Postby Stuka » Thu Apr 05, 2018 4:44 pm

It is not an easy swap. And it involves removing the windshield.

The later dash is setup for the later steering column which has all the dash functionality on the turn signal.

I would go after market long before swapping the dash.
1981 J10 AMC 258 with HEI and Weber 32/36 DGEV Carb, T176, NP208, D44/M23 with 4.56 gears and Detroit Locker, 6" lift, 33x12.50 Cooper STT's, BJ's Offroad Rear Dozer Bumper.
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weeegoneeer
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Re: Guage accuracy question

Postby weeegoneeer » Thu Apr 05, 2018 4:58 pm

Pretty sure a late model dash, which as said above would need a late model harness, would also need the matching engine / frame harnesses as well. Would also need to update the fuel sender and oil pressure sender. Sounds like a nightmare.
1984 GW

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babywag
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Re: Guage accuracy question

Postby babywag » Thu Apr 05, 2018 5:38 pm

kansasboy001 wrote:
babywag wrote:Then swap dash and whole harness, make it easier on youself.
Swap engine harness too, be less work than all little changes.

I’d swap column as well.

I was thinking that but how would I do the tailgate and rear defrost wiring? The j20 fuse box doesn't have the wiring for them. Other than that it'd pretty much be a bolt across swap


high probability wiring is there, switches are obviously not.
Adding it wouldn’t be big deal, just reuse your wiring if it’s not there, get newer style switches/pigtails if needed.

Again, whole lotta work for little benefit.
-Tony
'88 GW (aka Babywag) '90 GW (aka JunkBucket) both fuel injected.

letank
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Re: Guage accuracy question

Postby letank » Sat Apr 07, 2018 7:02 pm

in fact 86 and later senders are reverse than 85 senders for temp, oil press and gas. the 85 and older models read low with infinite resistance and the 86 and newer read high with infinite resistance or disconnected sender.... discovered when I swapped an 87 intake manifold on the 74... the temp went thru the roof after the engine had started, the coolant was not even luke warm.
Michel
74 wag (349 Kmiles... parked, next step is a rust free body)
85 Gwag (226 Kmiles... the running test lab)
See Engine bits and Fuel and brake lines, and Body work

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kansasboy001
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Re: Guage accuracy question

Postby kansasboy001 » Sat Apr 07, 2018 9:19 pm

letank wrote:in fact 86 and later senders are reverse than 85 senders for temp, oil press and gas. the 85 and older models read low with infinite resistance and the 86 and newer read high with infinite resistance or disconnected sender.... discovered when I swapped an 87 intake manifold on the 74... the temp went thru the roof after the engine had started, the coolant was not even luke warm.

Yes the whole system pretty much changed. Appears to be a fully amc designed system with 12v guages and not the old 5v Stewart warner guages in the older dash.
1983 Cherokee Laredo. 360/ 727/ np229/ Rochester quadrajet/ Msd ignition


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