TheSamba.com :: View topic - Slow Starter Turnover -Resolved

Sun Feb 14, 2010 6:45 pm

Can't quite figure this one out. '73 Bus. The engine is slow turning over. Starter engages fine, battery tests out okay, alternator charging the battery okay. It fires okay and starts after a few seconds even though it's turning over slowly.

It acts like I have a weak battery or a bad battery connection. I pulled the battery connectors and they seem fine. Cable to the starter looks good. Strap is firmly grounded. I pulled the connectors at the starter and cleaned them. Issue is intermittant. Sometimes it turns over like it should.

Is there another grounding strap somewhere? What am I missing?

Sun Feb 14, 2010 6:48 pm

Mine was doing the exact same thing. Turned out that the timing was off. Hasn't done it since...

Sun Feb 14, 2010 6:50 pm

transmission ground strap

Sun Feb 14, 2010 7:38 pm

I like the transmission ground strap idea. Can't see it from underneath. Where is it?

Sun Feb 14, 2010 8:23 pm

do you know how to use a volt meter? Do you have one, even a cheap one?

On a low scale like 12V or 20V etc read the voltage between battery posts. What is it? It should be about 12.5V

Same as above but have someone crank the bus for a second. What is it? It should remain near 12V or above. If it reads lower like 8V or 9V then either the battery is bad or the starter / engine is binding or has a shorted winding. Battery is the usual suspect.

On a low scale like 12V or 20V etc put the red lead on the 12V positive POST of the battery and the black lead where the 12V positive wire from the battery is held on with a nut to the starter. Have some one crank it for a second. What is it? It should be -0-. If you read any voltage then there is corrosion between the battery 12V positive post and the starter.

Do the same test as the one just before this but put the red lead on the transmission and the black lead on the negative battery post. If it reads any voltage when you crank then you have corrosion in the ground wires or strap.

Keep you body clear of moving parts when you do this. I buy some cheap 24" etc leads with alligator clips on them so the meter is hooked up and I can read it without being hurt if someone gets it going and dumps the clutch etc.

Mon Feb 15, 2010 5:59 am

SG:

Dump the clutch! Spooky thought. I think I'll put the bus up on jack stands to be safe. This kind of thing makes me nervous.

Yes, I have a meter. Haven't actually checked the battery while turning it over, but I have carefully inspected the cables and they seem fine. I'll try all three tests to be sure.

Is there a transmission ground strap on a '73? Where, exactly? Thanks.

Mon Feb 15, 2010 6:44 am

Crawl under the driver's side, just forward of the wheel. Look at the front of the transmission. Can't miss it. Should look like a braided battery ground strap.

Mon Feb 15, 2010 6:53 am

Clean all the ground straps on their mating surfaces and add a couple just to eliminate the ground issues. You might want to have the battery tested at the local shop.

Mon Feb 15, 2010 10:30 am

Alright get your meter, and check the battery, if your meter has a load feature, even better. If you do have the load feature load the battery. Then, grab ground from the engine, and load it, if the voltage drops more at the engine than at the battery then its the ground strap. They sell better ground straps than the braided kinds we have at auto part stores, just put on a new one.

Tue Feb 23, 2010 2:26 pm

For anyone interested, I think I have this beat. Long story short, the connector on the battery is one of those clamp style that clamp the wire to the connector instead of a crimp. Someone reworked it at some point. I pulled it apart, cut a little off, cleaned it and reassembled and it is working fine.

I intend to replace both ground straps and the positive cable to stop this from happening again.

Tue Feb 23, 2010 9:02 pm

Kudos for getting on it. Most do not know that the corrosion will travel down the cable(s). Hard to tell when the insulation still looks new. Early Mopar's have a huge problem with this.
You were schmart for cutting some off to get fresh copper.

Wed Feb 24, 2010 6:15 am

I'm a 20 year field guy with the worlds largest connector manufacturer, and what you say is an undeniable truth. Corrosion travels way, way up the cable. I've seen things on aircraft and vehicles that would curl your toes. I was cringing when I realized that was a clamp style on that battery connector.

About the only way to really make a battery cable reliable is with a good gas-tight crimp, which is attempted by some on battery connectors, then use tin plated copper wire, then tin-dip the whole end. Never seen that on a car, just military vehicles and some commercial trucks.

The other choice is a good grade of adhesive lined heat shrink over the crimp as a secondary moisture barrier. Done correctly, that will protect the wire for years, even around battery acid.

Wed Feb 24, 2010 9:46 am

For decades I have globbed the heck out of my cable ends and battery post with Vasoline, including the junction of the wire to the terminal. Works very well. I still have the original negative cable on my '72 Dodge truck. The insulation has cracked almost the whole length at this point from heat, grease, and age. But there is no visible corrosion. I carry a spare which I picked up years ago for if and when this original fails, but I am pig headed and just want to see how long I can get this one to last so I won't change it until forced to.

I consider the replacement style ends for emergency use only. I don't think I have run one on any of my own vehicles in over twenty five years. If I buy a used vehicle that has one on it they are removed as the first step in the restoration.

It is my preference to run a ground strap straight for the negative terminal on the battery to the engine on a bus. This lessens the likelihood of seeing a high current flow along the clutch cable if the ground strap fails. If you use a ground cable that has a second wire that can be run to the body the original ground strap will become redundant.