88 S10 Electrical Problems

[urbanknight]

I changed out the alternator, battery and battery cables.. Voltmeter gives me normal charge when off and on.. When I turn on the headlights, the in dash voltmeter droPs down to half and the gas gauge will go down to about .5 of a tank, and will start turning off the radio if I have it too loud.. this is annoying since it shouldnt be doing that and there are not enough audio comPonants or accessories to be loading the electrical system THAT bad... any Ideas...comments... etc...

[lieffer]

I have an 88 2dr , 2wd Blazer and I am having the exact same problems with my dash and I do not know what the problem is either.

[urbanknight]

Well so I went through a bit of testing the otherday, Used a multimeter and checked the drain on the battery and the fuses, When the engine is off it is a solid 12.7 V

Engine On No Load: 14.4

Radio On: 14.3

Lights on: 13.7

Lights and radio on: 13.4

There is no voltage shortage, I have a 100 Atlternator in there.. (sigh) this is bloody frustrating.

[urbanknight]

anyone?

[urbanknight]

Also, I just tested it yesterday with a circuit tester.. I hooked up a test lamp to the negetive terminal and the cable. It lit up brightly then pulsated on and off about once a second until I removed the ECM b Fuse then it stayed steadily on. If anyone could help me out I'm kinda new at this and I need any help I can get. Thanks..

[k-5_350]

check your grounds even if they look good, clean them. It sounds like you have gone threw all the troubleshooting steps. Hope this helps

[amac209]

sounds like your alternator isn't charging. get a shop to load test it and check the diodes. i've seen quite a few aftermarket alternators that were crap. a alternator with burnt out diodes will also drain the battery. i'd just take it back and tell them to give me a new one. this is assuming all the connections are good as K-5 350 mentioned.