alternator high voltage question

[jkinga1c]

i recently swaped a v-8 into my 86 ranger. it was originaly a 2.9 liter fuel injected. i used a 302 from a 79 f-100. used the alternater from the 79 and also wired a voltage regulater to it. replaced the voltage regulater 3 times and the alternater is brand new. my voltmeter reads around 17 volts at idle and around 18 if im running the engine over 1500 rpm. is this safe or is there something im missing. is that too many volts for my msd box and fuel pump.

 

[MAKG]

No, that's very high.

Is it regulated at all (i.e., do you get more voltage if you run it at 4000 RPM)? If not, it's miswired. If it's regulating, but at the wrong voltage, it may need an adjustment.

 

[jkinga1c]

yes i have a regulater on it the voltage goes up when the rpms do after i drove it for a while today it went down to around 14 at idle and max of 16. this only happens after i drive for a while. how do i adjust it i dont see an adjustment on the regulater. if i put a larger pulley on the alternater making it spin slower would that work or is the regulater supposed to keep it lower no mater how much the alternater is creating?

 

[Will]

Is it a solid-state regulator or an old point type? Is your gauge accurate? Put a Fluke on it and see before you panic.

15V is about the max you want to see with the engine running.

How about sketching us a picture of how you have it wired?

 

[MAKG]

My experience is with the old points-type regulator. You take the cover off and turn a screw to adjust the point gap.

They are built like one of the old Heathkit buzzer kits. Seriously. Bimetal spring heats up and breaks contact, cools and reconnects.

I'll suggest that if this is giving you trouble, you install an alternator with an integral regulator.

 

[jkinga1c]

not sure what kind it is its just a duralast replacement from auto zone. napa looks like they have the same one.

 

[jkinga1c]

drawing of how i wired my voltage regulater

 

[jkinga1c]

problem solved i ran a grounding wire from my alternater to the mounting screw of the voltage regulater. that grounded the voltage regulater, it was mounted to the plastic inner fender before so it couldnt ground. works good now.