GMC Repair: windshield wipers, electrical schematics, diagnostic worksheet

Question
Hello , I have a 99 new model Z-71 extended cab pick up with appx. 130K on it. The wipers only run high speed , could I need a new switch or do you think it's the wiper moter it self ? It has delay wipers but like I say they only work on high and you have to time it exactly right to get them shut off and end up at the bottom of the windshield. I know these electrical problems are hard to diagnose but I thought maybe it was some common problem that you may have run across alot and could say more than likely what the problem would be. Thanks Dan.

Answer
Without an electrical schematic and the proper diagnostic worksheet your problem could be either the SWITCH, WIRING, wiper control module or the wiper motor itself.

I do NOT know what type of wiper motor that your vehicle has on it as I do not have the exact book for a Z-71. However I do have several 99 books that have different types of wiper motors listed.

If you can take a picture of your motor and e-mail it to me at:

onlineautohelp@msn.com

I can identify it and provide you with electrical schematics and simple diagnostic test procedures to perform in order to diagnose your problem.

When you e-mail the pictures, PLEASE include this QUESTION and the specifics of your vehicle as I answer 20 to 40 questions daily and can't remember who wants what.


autohelp