'91 E350 7.5L gas - How to get to the alternator
 

Hello everyone,

I have a '91 E350 with 7.5L gas engine which has charging system trouble. Basically the battery doesn't charge when in the van. I still don't know if it's the battery or the alternator or anything else. I'm going to get the battery tested in the next couple of days (I don't have a charger or a tester), but if the battery is OK, I'm going to take the alternator out and get it tested.

I can see the alternator and the belt, but I can't get to it. The air cleaner housing (?) is in the way. My questions are,

1. Is taking the air cleaner housing off the easiest way to get to the alternator?

2. How do I get it off? Get those two small hoses on the front and the two hoses on the right off, then take the lid off, take the filter off and look around for a way to get bottom of the air filter housing off so I can access the belt? I'm a noobynoobynoob and I don't want to break anything :).

Here are the images ImageShack(TM) slideshow

3. This is not that important, but I'm just curious. What's that cylinder like thing in the last photo? It's in the front inside under the hood, driver's side.

Here's the image ImageShack(TM) slideshow

Thanks.

3. Is the vacuum reservoir for the emission system (TAB, TAD & EGR solenoids).

Yes you will have to remove the air intake ducts.

Got the battery tested and charged. They said the battery is OK.

Came back, reconnected battery and tried starting. Engine cranked without a problem and started. Did the alternator test again. I don't have a tachometer, so in the description below, judging by sound, 'low rpm' means about twice the idle rpm and 'high rpm' means about three times idle rpm. The voltage kept fluctuating sometimes, and the +/- error accounts for that.

Open circuit voltage before test 12.50 V.

Idle: 12.7 +/- 0.2 V without anything on, 11.4 +/- 0.2 V with headlights and cabin heater on full.

Low rpm: 12.4 +/- 0.5 V without anything on, 11.4 +/- 0.5 V with headlights and cabin heater on full.

High rpm: 12.2 +/- 0.2 V without anything on, 11.4 +/- 0.5 V with headlights and cabin heater on full.

Open circuit voltage after test 12.10 V.


So I disconnected the negative from the battery and started getting the air cleaner housing off. Here are some questions I have.

1. What are these two big hoses going to the right? Because they go in to the engine, I guess they are the engine air intakes? Here are the images. ImageShack(TM) slideshow

2. What are these two smaller hoses at the front? Images here. ImageShack(TM) slideshow

3. There is a small line at the right bottom. What is that? There was something like a square sponge, which I guess is a filter of some sort, where it starts, but it was not rigidly connected to the line. I don't know if I or someone else broke it. Are the square thing and the line supposed to be in two pieces or one? Images here. The line is in the center of the last picture. ImageShack(TM) slideshow

4. There is also a small line at left top. What is that? Here are the images. ImageShack(TM) slideshow

5. And finally there is a big line coming in from the bottom to the left edge of the air filter housing. I guess this is the air intake to the filter? Does this line just go to bottom of the vehicle or is there something before the air filter? Images here ImageShack(TM) slideshow

6. Finally got to the alternator. As far as I can see, there are two belts. There is a tensioner for the other belt, but there isn't one for the belt turning the alternator. How do I get the tension off the belt to get the alternator off? Here are the images. ImageShack(TM) slideshow

I thought I might be able to slip the alternator off without loosening the belt, and started taking the bolts off. But the second bolt seems to be too tight for my socket wrench which is only about 8" long. Maybe it's because of corrosion. Tried WD-40, but didn't work. Trying to find a steel pipe or something that I can use to extend the length of the socket wrench so I can get more leverage.

Replaced alternator, and it works fine now. Thanks.

Hello Eric,
How do you get the alternator off without loosening the belt? Is there a tensioner for the alternator belt? I'm try to take mine off.
Thanks
Viet