Windshield wipers don’t work after adding solenoid

[Mackcm]

Looking for help, and interested in if anyone else has had the same issue. I have an ‘89 itasca, and after the truck battery died a few times we realized the PO had removed the solenoid and wired the truck battery directly to the coach battery. I bought a replacement solenoid based on some posts here/in the Facebook group identifying which one I needed. https://www.amazon.com/gp/aw/d/B0797WZBD9?psc=1&ref=ppx_pop_mob_b_asin_title
 

We had a windshield wiper splice existing under the hood, so we used that (as per the wiring diagram) to attach to the perpendicular node on the solenoid. The notes on the wiring diagram are super hard to read, so I am assuming that the instruction is to splice the windshield wiper wire as the switch, but am not 100% sure. https://www.winnebago.com/Files/Files/Winnebago/Resources/Diagram/1990/084682.pdf

 

When we turning the engine on, the windshield wiper fuse was blown, and the solenoid didn’t have voltage to the coach battery side. 
 

We replaced the windshield wiper fuse and the wipers still aren’t working, and no solenoid voltage.
 

Anyone know where we went wrong, or have suggestions? I’ve have a hard time tracking down other itasca examples, and didn’t have existing wiring to copy so want to make sure I am approaching this correctly. 

[extech]

the relay you bought is for short time use. it will overheat if left on.  you need a constant duty relay. disconnect the wiper wire and see if the wipers work

[fred heath]

1 hour ago, Mackcm said:

Looking for help, and interested in if anyone else has had the same issue. I have an ‘89 itasca, and after the truck battery died a few times we realized the PO had removed the solenoid and wired the truck battery directly to the coach battery. I bought a replacement solenoid based on some posts here/in the Facebook group identifying which one I needed. https://www.amazon.com/gp/aw/d/B0797WZBD9?psc=1&ref=ppx_pop_mob_b_asin_title
 

We had a windshield wiper splice existing under the hood, so we used that (as per the wiring diagram) to attach to the perpendicular node on the solenoid. The notes on the wiring diagram are super hard to read, so I am assuming that the instruction is to splice the windshield wiper wire as the switch, but am not 100% sure. https://www.winnebago.com/Files/Files/Winnebago/Resources/Diagram/1990/084682.pdf

 

When we turning the engine on, the windshield wiper fuse was blown, and the solenoid didn’t have voltage to the coach battery side. 
 

We replaced the windshield wiper fuse and the wipers still aren’t working, and no solenoid voltage.
 

Anyone know where we went wrong, or have suggestions? I’ve have a hard time tracking down other itasca examples, and didn’t have existing wiring to copy so want to make sure I am approaching this correctly. 

You need an isolator that’s made for 12v use. A regular solenoid (starter type) is intended for short term use only. I’ve attached a link for an inexpensive isolator that I’ve used for over 6 years with no problem.

 

Stinger SGP38 80-AMP Battery Isolator and Relay,BLACK https://a.co/d/dDBzMrl

 

It’s common for people to grab the wire from the wiper motor to power the unit. It’s the most easily accessible “ignition on” power supply under the hood. This is a bad idea. The constant power drain by the isolator can affect the wiper operation. Early model Toyota actually lost the high speed function of the wipers due to the power draw.

 

Try to find another ignition hot circuit to draw power from. You need to have a good understanding of 12 volt automotive circuits. There are publications out there that explain the basics. A 12V test light is a must have.

 

The isolator comes with instructions for installation.

[Mackcm]

Thanks both, should have been clear that the wipers still don’t work after fuse was replaced and the wire was removed from the solenoid. And of course have been using a multimeter to test. 
 

and thanks for the updated link. Frustrating that the wiring diagram/other posts on this subject sent me in the other direction on what solenoid to buy. 
 

Clearly I’m unfamiliar with where else to pull a switch wire from the alternator but I will keep looking. 

[fred heath]

3 hours ago, Mackcm said:

Thanks both, should have been clear that the wipers still don’t work after fuse was replaced and the wire was removed from the solenoid. And of course have been using a multimeter to test. 
 

and thanks for the updated link. Frustrating that the wiring diagram/other posts on this subject sent me in the other direction on what solenoid to buy. 
 

Clearly I’m unfamiliar with where else to pull a switch wire from the alternator but I will keep looking. 

Check the condition of the wiper motor wire itself that was used for power. Many times those cheap plastic wire taps will sever the copper conductor. Whenever I remove one of those, I always install a new splice.

 

As far as “ignition hot” wire goes, look for any unused emission control plugs.

Many times you’ll find power there.