I have a turbo b20/b16 transmission obd0 in an ef hatchback. Ive been chasing overheating issues and flickering tach problems, and I finally discovered the cause when my speedo cable happened to shake out of its socket on the transmission today. As soon as it came out of its hole, my tach stopped bouncing, my coolant temp dropped to normal, and my lights stopped flickering with my turn signals. Im so relieved, but need some pointers. I dont understand how a mechanical speedometer can cause these electrical issues. Its cable driven! Am I missing something?

 

If I jiggle the speedo cable at the transmission the gauges go nuts. Wtf.

 

Check the thermostat ground and all other grounds.

 

I did that before I even knew this was the problem. I even added 3 extra grounds.

 

I'm starting to think that maybe there is a faulty ground related to the cluster or something, and it makes intermittent ground through the speed cable, and as I jiggle it, I break and reconnect that ground. Odd.

 

Actually I found on my da (and all da integras that ive worked on) ground the cluster through the speedo cable. Its bizzare I know but pulling the cable out causes the cluster to freak out in strange ways. Hook it back up and alls well again

 

Weird. My speeds mechanical sender in the tyranny is bad in my ef n my tach cluster is fine.

 

On my prelude the speed sensor assembly was only held down by one bolt on an arm sticking off the module. The arm broke off and the gear into the tranny wouldnt hold in. Dunno if civics are the same way, never owned one.

 

Huh. Yea it sounds like its grounded through the cable, does it show it in DA teg helms manual schematics?

 

It doesnt show that its supposed to ground through the cable. The cluster has 2 harness grounding points. One by the windshield washer bottle, and another by the fusebox. Theyre those bulk wire things that bolt onto the body. And as far as I cam remember, g301 (by the washer bottle) isnt bolted on my car and just hangs out. But I could be wrong.

Anyways it sounds like a missing ground causes the issue. Ill bet if you made a ground going from the cluster main ground to the body it would stop freaking out when the cable slips out