Starter Relay Rattle?

[The Baron]

I have a 1984 M1009, and have done the Doghead relay modification. The starter will not turn. When I turn the key the starter relay begins to make a rattling sound. I tried replacing the relay and it made no difference. From what I have read this may be due to bad batteries. A week ago I took my 5 year old batteries in to Autozone to have them tested and they tested out as good. I have cleaned the battery terminals as well. Is there a possibility this test was wrong and the batteries are bad? Any ideas what may be wrong?

 

[Jeeperjoe]

Did they give you a CCA reading on the Batts? That could be the issue.. otherwise I'm no real help here

By rattle do you mean fast clicking? If so sounds like bad Batts

 

[Tinstar]

Did they load test them or just slap a voltmeter on it?
A battery will read fine, but fail a load test.
Since yours are 5 years old anyway I would replace them.

 

[The Baron]

I don't think they bothered. I question if they know how to use any of the equipment they have. I will try replacing them.

 

[cucvrus]

Just load test them. I have 5 year old batteries in one of my M1009's and it starts fine. i will think about getting new ones when they don't load test anymore. I have a tool that checks all the CCA and such. It was a bit expensive but it has lasted a long time. But yes load testing is needed. getting 12 volts means nothing. I see guys arc a screw driver across the posts and if it snaps they say the battery is good. Not the case.

 

[Tinstar]

5 years in the battery world is a long time.
I know some can and do last longer (like yours), but I would still recommend replacement.
The older the battery, the greater the chance it will leave you stranded. Usually at the worst possible time.

Good battery's, with a full charge, makes troubleshooting CUCV issues a whole lot easier.

I would rather replace them early and continue driving, than try and wring the life out of them and have to maybe walk later.

When they fail, they are DRT. (Dead Right There).