'91 120 evvie - tach vs VRO

[baggywinkles]

I disconnected the VRO on my engine and separated the 4-wire plug from the VRO to the console. Now, my tach jumps all over the place: pegs itself, drops to zero and in a few minutes works fine. Then it repeats the whole process. Am I dealing with a problem because of the disconnection of the alarm plug or is it something totally separate?<br />jimmy, port charlotte fl

 

[Dhadley]

Re: '91 120 evvie - tach vs VRO

Should be two seperate deals. Plug it back in and see what happens. The alarm will beep at you but see if the tach straightens out.<br /><br />Interesting.

 

[clanton]

Re: '91 120 evvie - tach vs VRO

I cant remember, but some of the early engine used the tach signal wire to power the VRO alarm. Look for a gray wire in the vro plug. The gray wire should come from the regulator to tach, with a jumper to the vro harness. If this is not the case, check for loose and dirty connections. I can look at oem manual next week for wire location next week, if needed.