Tach Fuse

Terry C

Registered User
My Ford Shop Manual, for my 92 Super Coupe, says there is a tach fuse. I can not find it anywhere, the fuse panel under the dash or the one in the engine compartment. Is this a miss print or could someone please tell me where to locate it. It is suppose to be a 10 amp fuse.

Terry
 
I know. It says it is a 10 amp fuse. I checked all the 10 amp fuses in the panel and none are broken.
 
There is no fuse specifically for the Tach circuit. There is 10 amp fuse for the whole cluster though- temp guage,oil guage,check guage light,fuel guage, speedo & tach.12 volt is supplied to the cluster through connector C142 which is supplied by the ignition primary junction block. If the cluster fuse was bad, none of the guages, the check guage light or speedo would work. Ground signal for the tach is supplied by C170 at DIS module on engine to C120 at right side cowl to C142 at vehicle maintenace monitor, then out of maintenance module to C157 at instrument cluster. Hope that helps.
 
Yes. All the other gauges and lights work. Also I didn't see Tach mentioned on the fuse panel either. Thank you for your help.
 
That's correct, that fuse is marked as cluster.

Not sure why your manual would say there is a tach fuse.
 
In that case, 214 takes you back to the D.I.S module & its related imput's(wiring & signal) from the cam sensor which is where the the tach gets its signal from.
The 2 issues are related.
 
Yes it is KMT. There is a test for the VMMM and it fails step one - no tach input. No further tests can be ran with out the tach input. I have been wire checking for continuity and grounds - found nothing wrong yet, including the tach input to the VMMM.
Doug, I have been fighting this problem since 2004. At first it would go into limp home mode. (two cylinders & tack working)) It seem to be the DIS. I have replaced many of them over the years. Now it bucks, tach intermittent and dies. (2013-2016) I can get it started, no tach & CEL on to get it home.
I just replaced the main forward harness, (thanks KMT) DIS, Cam & Crank sensors with parts from Super Coupe Performance in February. It died on the way home. (about 7-8 miles) I did mange to get it home and have been working on ever since. I even changed EEC's. (good second computer) No help.
I do have a new coil coming today and will try that. If that fails, I'm going to try the DIS that KMT sent me. You never know. Maybe another DIS from NAPA, that fixed everything in 2016, till December of last year when it started to die again.
 
I fixed my problem. After talking to Bill at Super Performance, who said the Cam Sensor several times. (Doug H, you were also correct, I should have paid more attention.) I went out to the car to check it out. As I was removing the harness connector, I noticed it didn't seem plugged in all the way. I saw there was a new rubber moisture seal in the cam sensor plug and one on the harness connector to it. (two seals) No wonder it did seat correctly. I removed the one on the harness connecter, plugged it back in the cam sensor and put the belts back on. Got in, it started right up with a working tach and no engine check light. Yea!!! Took it for a short test drive and everything seems to be working. I will continue to drive it some more to reprogram the EEC module. (computer) Thank you to everyone for your help.
 
Thanks for the update Terry, glad to hear everything is resolved.

2 seals would prevent it from connecting properly for sure. I've never
done it, but other guy's in our shop have installed new oil filters with the old
seal still stuck to the filter head/block.
 
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