QuestionHey john,
I read and answer you gave someone about his land rover tach not working the right way. First off I'll explain what is going on.
I replaced a squeaky belt with a new one and one day after work I didn't let is warm up like I usually do and kind of stepped on it to pass someone. The squeak came back then I noticed the tach would stop working, not all the way but it would sit right about at 0. The lights then dimmed and the air slowed.
When i start the truck the srs light comes and and most the dash lights flicker. After about 10 min without the lights on the tach will start working but when i turn the air and lights on it drops.
When I start driving and shut the air off the tach will start working and stay on untill i stop at a stop light, then i have to do the process of turning the air off to make it work.
Thinking the alternator was bad i replaced it and it continues to do the same thing.
Tested the alternator with my multimeter it puts out 13.7 or something when the tach is working, 12 when the air is on, and 9 when the lights and air are both on.
Looking at the belt I heard theres 2 ways for it to go on, the right way and the wrong way. I'm pretty sure its on the right way. The ribbed part is down and it also worked fine until i stepped on it the one night. The belt is also hanging off the tensioner pulley about 1/8 inch and what looked to be rubber shavings from the belt were all over the old alternator. The belt looks like its in the right spot on everything else other than the tensioner.
I live in Minnesota in the freezing cold so when i start it in the mornings it acts like its not charging at all, but after about 15 min everything will fully work without having the lights on. letting it warm up for about 30 min will let everything work perfect even the lights and it will stay working for awhile.
Just wondering any thoughts on that and if you finally came to a conclusion of what is going on as I've seen many forum posts on the same topic and really no clear answer to what is happening. I just don't want to go out and buy a $158 tensioner if that is not quite it. The tensioner seems to have good tension, i tried to wiggle it by hand and it doesn't move at all, but with a wrench it will so its not seized.
AnswerThe voltage readings you supply tell me the alternator is not delivering enough output under load. The belt may be slipping, or the unit may be bad. It's one of those two possibilities. Your description leads me to wonder if the belt is routed right and under good tension. It's also possible you have the wrong belt or the tensioner is bad. I don't know how to post a picture here but if you do a google image search for "land rover v8 belt routing" you will see images of the standard configurations. Is yours right? If not, get it corrected, and if it is right, you have to decide if the tensioner is loose, the belt is too long or the alternator is just no good.
