electric fan causing reset

[1986mitz]

hows it going. I finally drove my 1986 Montero with turbo and micro today. it ran decent till my electric fan came on .. engine died and would not restart. Im running a hall sensor from DIY , its pretty close to alternator. im going to try shielding it some more tomarrow.. it lost rpm signal , I thought I lost sensor , sync , and or burned my ecm. I ran test on sensor and its putting out 9.6 volts while turning crank over tooth . my battery voltage was 12.6. does hall sensor show same voltage that is being supplied to sensor. I may have a weak ground path. im gona verify my grounds tomarrow. also wondering if my old alternator is putting out enough amps to run my electronics . Im just fishing for info, trying to get my project reliable so I can drive it to my new place. don't want to have to tow it you know... lol. any ideas will be great thanks. My jeep restarted after it sat for a bit, not sure if it reset or what. here is my last msq.. thanks again.

[Matt Cramer]

The battery voltage did take an abrupt dip when the fans came on, but it's hard to tell if it is an overtaxed alternator or from the RPM drop.

I'd check grounding too. Definitely seems to be SOMETHING keeping it from getting a good signal from the Hall sensor.

How exactly is the Hall sensor wired up?

[1986mitz]

Hey Matt , I have separate power and ground to hall sensor . swithed 12v and block ground, and signal going to vr pos. Though I noticed when I checked sensor signal on my test its putting out 9.6 volts and supplied volts was 12.6. im gona work on pimping out the grounds today. Maybe voltage drop on ground side?? Thanks ...

[1986mitz]

I had another thought. My missing tooth gap is real close to sensor . it just about touches first tooth at tdc. I have not set up , or calibrated the timing . the auto trigger function. im close at around 10 deg. I should pimp out the timing right. Im going to add a wasted spark soon, so I should do it now right... I need to use a timing light to match up right?? thanks

[Matt Cramer]

Please make sure VR negative is NOT connected.

[1986mitz]

Hey Matt . Yes I have neg on vr taped off. Question , hall gap is best around 1mm? I have it at .5mm . I will move it. I've read too close is bad as well as too far.

[1986mitz]

Fixed.. Turned out to be a bad hall sensor input. I installed a vr to vr1 circuit and adjusted air gap to 0.33 and been solid ever since.