The Bodyman

I bought a 1989 C-4
Bought a new battery car starts no problem. Alternator checked last week at advanced auto they said "all is good". Car sits for couple days dead. Parasitic draw. Check fuses with my meter no more than .38 draw. Today the only way car will continue to Start and keep running is battery cables from my truck to car. As soon as I disconnect cables car dies and won,t start. This is the first of many issues.

A Peter C4

Autozone has checked alternaters for me before and said they were good, put on car and no charge so do not believe them everytime. Are the connections good and clean and tight at battery, is battery full charged to start when testing? Is ground cable on car end connection good?

Klondike

Disconnect your battery and charge it up. Just put your + battery cable back on but leave the ground cable off. Then pull your interior lights fuse so you can work with the door open and not draw power for the courtesy lights. (Hopefully that isn't your problem line) Put your meter on amps and connect the plus lead to your neg battery post with an alligator clip and the neg meter lead to ground. You should see your current draw on the meter then. Start pulling and replacing fuses one at a time till you see the meter current take it's biggest drop. That should be the circuit with the problem drain. Might not tell you exactly what or where, but it will narrow it down to what's on that fuse line. You may have just a little reading from something like the clock, but it should be minuscule in the milli-amps and not your problem drain. Good hunting.

bac22

Not sure about an 89, but on my 96 the car doesn't draw anything more then 30mA (.03A) when sitting which is normal...you said you saw no more then .38A draw...not sure of an 89, but over a 1/4 of an amp seems awful high.

I guess you might see that on the fuse that powers the indoor lights. What circuit was drawing .38A?

Also, not sure of an 89, but on my 96 there are fuses under the hood as well that need to be checked for a draw.

scuba717

+1 on Klondike's suggestion for parasitic draw. At .38A your draw is way too high s/b in the mA range. But might not be your only problem. If the car won't run w/o being connected to your truck. It's in the alternator/regulator/charging circuit. As always, make sure your grounds are clean.

Paul Workman

.38A is 380 mA...a little over 10x as much as it should draw. 380 mA is typical if there is a courtesy bulb running somewhere. (My wife's C3 light in the rear storage compartment was on - due to a bad switch. I discovered it by accident - walking past the car in the dark and saw the glow around the edges of the compartment hatch!)

And, just for the record, you DON'T have to take your car to someplace to see if the alternator is charging, IF you have a volt meter handy:

With the engine running, the alternator will be putting out 14.6 volts (cold), and drop back to approx 13.4 to 13.8 after running and under-hood temps are fully heated up. But, if it reads approx the same as the reading at the battery with the engine off (12 something volts), then it is NOT charging for some reason.

And, you can get an idea if the batter is up to snuff too, w/o having to go to a shop to have it tested.

The battery test amounts to a load test to see if the battery can maintain a minimum spec voltage with a specific load applied. The shop will first fully charge the battery, and then hook it up to a "dummy load" which will draw several amperes. After a set amount of time (seconds), the voltage is read and must exceed a minimum (usually above 10.1 volts) to be considered "good".

You can (sorta) do your own battery load test at home under real conditions. IF after cranking a fully charged (series 75, lead-acid) battery for about 7-10 seconds (distributor disconnected to prevent starting) and the battery voltage is still above 10.1 volts while cranking, the battery is OK. (If you want to test the battery again, you'll need a charger to first fully recharge the batter, but DO let the starter cool down for several minutes or damage may occur if test is repeated before it cools sufficiently.)

You should know that if this "shade-tree mechanic's load test" results in a voltage less than 9 volts, the battery is shot, and due to be replaced. A ZR-1 will NOT run if voltage dips much below 10 volts. The ignition typical of the L98 is a little more tolerant - will usually run still well into the 9s or slightly less, I find.



P.

The Bodyman

Still working on all the above. Hope tomorrow to have some good news.

Cliff Harris

The most common parasitic draws are motors that should turn off but don't. Likely suspects are the antenna, seats and headlights.

hcbph

There are DVOM's that will read dc amperage via the clampon's and can be useful to help track things down. Another is the meter shown, you pull a fuse from the fuse block, put it into the meter body and plug the pigtail into the slot in the fuse block. It shows the draw happening through that particular fuse. There are also some circuit breakers on the front of the fuse block. It can measure them too but you'll need to make up some pigtails to accomplish that.

Good luck.

The Bodyman

Looks like a very convenient tester. Yes, I will go buy one. I'm a bodyman not a mechanic, I am trying to learn. lol. If you can offer me a brief description of attaching pig tails for circuit breakers that would be helpful. TY

The Bodyman

Ironically decided to check circuit breakers in fuse box (30 minutes after car was shut down) the power accessory 30A circuit breaker was extremely hot to the touch. Another issue that just showed up. Lucky I checked or battery would have died and me scratching my head.

auggy

My 94 draws 350 m/a(a third of an amp) for 15 minutes then drops to 20. Its the lighting control module doing it. .38 might be 380 m/a depending on your scale. Anything above 50 m/a is not ok.I don't like this and got tired of the battery drain. After enough time it's going to cause premature battery failure. Now after I put the car away I disconnect the neg battery cable. Put the little dedicated socket wrench right on the battery so I know where it is. No worries anymore and the battery stays on a near full charge.

The Bodyman

Update: Electrical Nightmare!
Alternator was not charging battery. Bench test all good. Replaced Belt tensionor, spring was no good belt slipping and pigtail to alternator was spliced before I bought the car so replaced pigtail to be sure connection was good. Good news 13.9 /14.2V when running.
A/C clutch was smoken ordered a new clutch assem., pulley turns but makes a nasty noise.
A/C compressor did not seem to be seized.
I mentioned earlier about a battery draw pulled out crsty lamp fuse it's been 24 hours battery at 12.6V. Thought I found problem. Decided to check circuit breakers in fuse box (30 minutes after car was shut down) the power accessory 30A circuit breaker was extremely hot to the touch. Another issue that just showed up. Lucky I checked, or battery would have died and me scratching my head. Thank You Cliff Harris.
I am going to put the courtesy light fuse back in and keep the 30A pwr accy circuit breaker out. Hope for the best tomorrow. Battery is at 12.6V now. I don't know how to test battery draw at the breaker some help would be appreciated.
TY Cliff.
My guess is the switch for Power locks, Power Seats, Trunk, Mirrors or another item that could work without car running my be stuck on. Maybe the problem and hope the solution?

bac22

Follow Klondike's post and go from there, it's easy to do.

When I was having trouble I actually got about 10' 2 strand stereo wire with 4 alligator clips. Pulled the negative battery cable and connected 1 alligator clip to the negative battery post and the other alligator clip negative battery cable. The other side connected to each lead of my volt/amp meter...basically creating a continuous path for the power. That way I could have my volt meter next to me while pulling fuses

My problem turn out to be the ASR module that I had to replaced.

The Centech product is a nicer/cleaner way to go though...been thinking of getting one myself...can grab them at Harbor Frieght
https://www.harborfreight.com/30-amp...ter-67724.html

Paul Workman

Dittos on the Centech! I have one (also fm Harbor Freight) and keep in handy.

Davis Tremblay

Yes this might be an electrical nightmare and this problem has been resolved by a car mechanic and not an electrician.

cdm747

And what the heck is that supposed to mean.

Hot Rod Roy

Another ancient post!!!