Gauzes and tach down

[Chiclassics]

So it was raining in southern California last 2 days. After the rain i took out my bronco for a drive(it was left out during rain). And I started smelling like a subtle burning thing for few mins and it stopped (electrical/oil burn cant tell). After a while my temp, oil , fuel gauges stopped working, along with after market tach((Toms) . The car does start, lights , signals, wipers all work just the gauges and tach stopped working. I was going to open up the gauge cluster to see if my IVR burnt out(I recently put a new one earlier this week) but before I do that I wanted to see if someone dealt with this before and could be because of another point of failure, given my tach also stopped working at same. Is there some sort of common thing between these 2?

 

[joebronco73]

So it was raining in southern California last 2 days. After the rain i took out my bronco for a drive(it was left out during rain). And I started smelling like a subtle burning thing for few mins and it stopped (electrical/oil burn cant tell). After a while my temp, oil , fuel gauges stopped working, along with after market tach((Toms) . The car does start, lights , signals, wipers all work just the gauges and tach stopped working. I was going to open up the gauge cluster to see if my IVR burnt out(I recently put a new one earlier this week) but before I do that I wanted to see if someone dealt with this before and could be because of another point of failure, given my tach also stopped working at same. Is there some sort of common thing between these 2?

Check your IVR, but is your gauge cluster updated with the volt meter? If so, check your "hot" 12V leads and grounds. If you smell hot/burning wires, you have a short and something is overloading the wire(s).

 

[Broncobowsher]

I don't remember the wiring for the gauges. Have not messed with a stock fuse box in decades.
Guessing the tach is powered off the power into the IVR? It's aftermarket so anything is possible.
If the IVR died, and what you describe it sounds like it did, it caused enough of a short to take out a fuse (hopefully) and that took out everything on that circuit.
Replace IVR, verify there isn't any odd shorts going on there, change the fuse. Should be a simple fix.
Unless it actually fried wiring and the wire acted as the fuse. No remote control help for that one.

 

[Chiclassics]

Ok, I dug into it this a little.

I have a painless wiring harness. Apparently both gauge cluster and tach are fed by same fuse of 10amps(Pic below). The fuse came installed with wiring harness so I am assuming its the right load. It ran fine last few months where my fuel gauze and oil pressure were working okay but not ideal. Realized my old IVR was giving out unreliable output 8/10/11v which was causing fluctuations in the gauges but never had fuse blown.

I replaced IVR with new one from WH.(not solid state one but the thermal one). I checked that output is pulsating 6v. So i know IVR is functioning okay. But i started noticing this blown fuse issue only after changing IVR. Btw I changed another fuse this afternoon which also was blown after 10min drive. For those 10mins both my fuel gauge and oil pressure were giving accurate readings.

My gauge cluster is grounded stock style - by the holding screws to the dash.

My questions are
1) is 10amp not enough to feed gauges and tach?
2) if something is grounding where should I check ?
3) any other possible reasons?

https://imgur.com/a/xFL9iMb

 

[B RON CO]

Hi, I would not try a bigger fuse, for a simple test, I would disconnect the tach and see if that eliminates the fuse blowing. Good luck

 

[Broncobowsher]

Do not upsize the fuse. You quickly move the fuse burning up into the wiring burning up.
disconnecting loads off the circuit is the correct way to tell which load is the overload.

 

[Chiclassics]

Update
I opened up gauge cluster noticed a slightly cut positive wire that was going to tach I taped it up and switched back to old and IVR its holding good now. Im
Going to wait couple of days and then switch to new IVR and see if fuse blows again then probably I’ll know it’s IVR

 

[Chiclassics]

So far my old IVR holds well no fuse blows. Its little off but works. Still not sure if it was the new IVR or the exposed tach positive wire that was causing the ground. I am going to just leave the old IVR as it is until it completely dies. My fuel gauge seems to work , which I mostly care about, everything else my spidey senses can pick up (haha)

 

[DirtDonk]

Since all three gauges are on a common wire, either that wire is wonky or there’s something wrong with the other two gauges.
The old IVR is probably adjustable. If you think it reads a little low, you might be able to tweak it upward a little with the dashpot screw thingy.