1994 850 Alternator Issue

Post by **shaker_chi** » 02 Aug 2014, 12:02

My 1994 850 n/a has 205,000 on it. At 200,000 the alternator went out and I installed a rebuilt Bosch. Yesterday, my battery was dead and when I did the quick test (remove negative post while running) the car died. My question is, why isn't my electrical/charging light lighting up in the dash. The bulb works, but it never lit up. What triggers this? I had to work today, so when I get home tonight I'll put the multimeter on it and see what's going on. Thanks.

Post by **Ozark Lee** » 02 Aug 2014, 13:42

For starters it is kinda dangerous to run the car without the battery. The battery prevents voltage spikes that can happen from just the alternator. In the old days, before electronic ignitions, it was perfectly acceptable but I would wouldn't it recommend on a car with a computer controlled ignition system.

If the battery light isn't on then the alternator should be working. You can get an auto parts store to load test it to make sure it is putting out something close to what it should. The test is painless and they can do it with the alternator in the car.

My guess is that you have a parasitic draw problem. The glove box light falls into the usual suspect list but you can put an ammeter in series with a battery cable and check the draw. If it is excessive you can pull fuses until you locate the circuit that is causing the problem.

...Lee

Post by **abscate** » 02 Aug 2014, 18:43

shaker_chi wrote:My 1994 850 n/a has 205,000 on it. At 200,000 the alternator went out and I installed a rebuilt Bosch. Yesterday, my battery was dead and when I did the quick test (remove negative post while running) the car died. My question is, why isn't my electrical/charging light lighting up in the dash. The bulb works, but it never lit up. What triggers this? I had to work today, so when I get home tonight I'll put the multimeter on it and see what's going on. Thanks.

Your alternator could be putting out fine but your battery is simply not accepting the charge.

Disconnecting the battery while running is not only not testing anything, it's potentially damaging.

Post by **rspi** » 03 Aug 2014, 02:59

Post by **tryingbe** » 03 Aug 2014, 11:12

rspi wrote:cleaning wires/cable videos

I replaced the alternator to starter, starter to battery and ground cables with 0/1 gauge welding wires using this wire crimping tool.
http://www.harborfreight.com/hydraulic- ... 66150.html

With headlights on, defrost on, a/c on, I get solid 13.6V at the battery.

It worked so well that I also upgraded my sister's 240 battery and ground cables.

Check out how much bigger the 0/1 welding cable is compare to stock positive cable.

Post by **shaker_chi** » 03 Aug 2014, 17:28

Thanks for the responses. My cables are 21 years old, so maybe it's time to replace.

Post by **tryingbe** » 03 Aug 2014, 18:37

shaker_chi wrote:Thanks for the responses. My cables are 21 years old, so maybe it's time to replace.

Before you spend any money to replace any parts, buy yourself a multimeter. A cheap one from habor freight will do.

You need to figure out why your battery is not charging before putting money into parts. How old is the battery? Cable ends making good contacts? Auto parts store will test alternator/battery for free.

To test the battery to starter/starter to alternator cable, I do this test.

With everything turn on and car running (headlight, a/c, rear defrost, etc), measure the alternator pos to the battery pos and see what the voltage drop is. Lower # is better. I've seen 1.2 voltage on my 85 Dodge GLH before.

If you want to upgrade the battery to starter, starter to alternator, and the ground cables, here is what you need to buy.

http://www.ebay.com/itm/181074818504?ss ... 1497.l2649

http://www.ebay.com/itm/261298170208?ss ... 1497.l2649

http://www.harborfreight.com/hydraulic- ... 66150.html

With everything on and cable replacement, my 850's voltage drop between the pos of the alternator and the pos end of the battery is now .07 V vs .7 V before.